Grcov report - shared

1

//! Shared access to Cairo image surfaces.

2

use std::cmp::min;

3

use std::marker::PhantomData;

4

use std::ptr::NonNull;

5

use std::slice;

6

7

use cast::i32;

8

use cssparser::Color;

9

use nalgebra::{storage::Storage, Dim, Matrix};

10

11

use crate::color::color_to_rgba;

12

use crate::drawing_ctx::set_source_color_on_cairo;

13

use crate::error::*;

14

use crate::rect::{IRect, Rect};

15

use crate::surface_utils::srgb;

16

use crate::util::clamp;

17

18

use super::{

19

    iterators::{PixelRectangle, Pixels},

20

    AsCairoARGB, CairoARGB, EdgeMode, ImageSurfaceDataExt, Pixel, PixelOps, ToCairoARGB, ToPixel,

21

};

22

23

/// Interpolation when scaling images.

24

///

25

/// This is meant to be translated from the `ImageRendering` property.  We don't use

26

/// `ImageRendering` directly here, because this module is supposed to be lower-level

27

/// than the main part of librsvg.  Here, we take `Interpolation` and translate it

28

/// to Cairo's own values for pattern filtering.

29

///

30

/// This enum can be expanded to use more of Cairo's filtering modes.

31

pub enum Interpolation {

32

    Nearest,

33

    Smooth,

34

35

36

impl From<Interpolation> for cairo::Filter {

37

149

    fn from(i: Interpolation) -> cairo::Filter {

38

        // Cairo's default for interpolation is CAIRO_FILTER_GOOD.  This happens in Cairo's internals, as

39

        // CAIRO_FILTER_DEFAULT is an internal macro that expands to CAIRO_FILTER_GOOD.

40

149

        match i {

41

1

            Interpolation::Nearest => cairo::Filter::Nearest,

42

148

            Interpolation::Smooth => cairo::Filter::Good,

43

44

149

45

46

47

/// Types of pixel data in a `ImageSurface`.

48

2463

#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]

49

pub enum SurfaceType {

50

    /// The pixel data is in the sRGB color space.

51

    SRgb,

52

    /// The pixel data is in the linear sRGB color space.

53

    LinearRgb,

54

    /// The pixel data is alpha-only (contains meaningful data only in the alpha channel).

55

///

56

    /// A number of methods are optimized for alpha-only surfaces. For example, linearization and

57

    /// unlinearization have no effect for alpha-only surfaces.

58

    AlphaOnly,

59

60

61

impl SurfaceType {

62

    /// Combines surface types

63

///

64

    /// If combining two alpha-only surfaces, the result is alpha-only.

65

    /// If one is alpha-only, the result is the other.

66

    /// If none is alpha-only, the types should be the same.

67

///

68

    /// # Panics

69

    /// Panics if the surface types are not alpha-only and differ.

70

72

    pub fn combine(self, other: SurfaceType) -> SurfaceType {

71

72

        match (self, other) {

72

4

            (SurfaceType::AlphaOnly, t) => t,

73

6

            (t, SurfaceType::AlphaOnly) => t,

74

62

            (t1, t2) if t1 == t2 => t1,

75

            _ => panic!(),

76

77

72

78

79

80

/// Operators supported by `ImageSurface<Shared>::compose`.

81

pub enum Operator {

82

    Over,

83

In,

84

    Out,

85

    Atop,

86

    Xor,

87

    Multiply,

88

    Screen,

89

    Darken,

90

    Lighten,

91

    Overlay,

92

    ColorDodge,

93

    ColorBurn,

94

    HardLight,

95

    SoftLight,

96

    Difference,

97

    Exclusion,

98

    HslHue,

99

    HslSaturation,

100

    HslColor,

101

    HslLuminosity,

102

103

104

/// Wrapper for a Cairo image surface that enforces exclusive access when modifying it.

105

///

106

/// Shared access to `cairo::ImageSurface` is tricky since a read-only borrowed reference

107

/// can still be cloned and then modified. We can't simply use `cairo::ImageSurface::data()`

108

/// because in the filter code we have surfaces referenced from multiple places and it would

109

/// probably add more complexity to remove that and start passing around references.

110

///

111

/// This wrapper asserts the uniqueness of its image surface.

112

///

113

/// It uses the typestate pattern to ensure that the surface can be modified only when

114

/// it is in the `Exclusive` state, while in the `Shared` state it only allows read-only access.

115

2842

#[derive(Debug, Clone)]

116

pub struct ImageSurface<T> {

117

1421

    surface: cairo::ImageSurface,

118

119

1421

    data_ptr: NonNull<u8>, // *const.

120

1421

    width: i32,

121

1421

    height: i32,

122

1421

    stride: isize,

123

124

1421

    surface_type: SurfaceType,

125

126

1421

    _state: PhantomData<T>,

127

128

129

#[derive(Debug, Clone)]

130

pub struct Shared;

131

132

/// Shared state of `ImageSurface`

133

pub type SharedImageSurface = ImageSurface<Shared>;

134

135

#[derive(Debug, Clone)]

136

pub struct Exclusive;

137

138

/// Exclusive state of `ImageSurface`

139

pub type ExclusiveImageSurface = ImageSurface<Exclusive>;

140

141

// The access is read-only, the ref-counting on an `cairo::ImageSurface` is atomic.

142

unsafe impl Sync for SharedImageSurface {}

143

144

/// A compile-time blur direction variable.

145

pub trait BlurDirection {

146

    const IS_VERTICAL: bool;

147

148

149

/// Vertical blur direction.

150

pub enum Vertical {}

151

/// Horizontal blur direction.

152

pub enum Horizontal {}

153

154

impl BlurDirection for Vertical {

155

    const IS_VERTICAL: bool = true;

156

157

158

impl BlurDirection for Horizontal {

159

    const IS_VERTICAL: bool = false;

160

161

162

/// A compile-time alpha-only marker variable.

163

pub trait IsAlphaOnly {

164

    const IS_ALPHA_ONLY: bool;

165

166

167

/// Alpha-only.

168

pub enum AlphaOnly {}

169

/// Not alpha-only.

170

pub enum NotAlphaOnly {}

171

172

/// Iterator over the rows of a `SharedImageSurface`.

173

pub struct Rows<'a> {

174

    surface: &'a SharedImageSurface,

175

    next_row: i32,

176

177

178

/// Iterator over the mutable rows of an `ExclusiveImageSurface`.

179

pub struct RowsMut<'a> {

180

    // Keep an ImageSurfaceData here instead of a raw mutable pointer to the bytes,

181

    // so that the ImageSurfaceData will mark the surface as dirty when it is dropped.

182

    data: cairo::ImageSurfaceData<'a>,

183

184

    width: i32,

185

    height: i32,

186

    stride: i32,

187

188

    next_row: i32,

189

190

191

impl IsAlphaOnly for AlphaOnly {

192

    const IS_ALPHA_ONLY: bool = true;

193

194

195

impl IsAlphaOnly for NotAlphaOnly {

196

    const IS_ALPHA_ONLY: bool = false;

197

198

199

impl<T> ImageSurface<T> {

200

    /// Returns the surface width.

201

    #[inline]

202

770001

    pub fn width(&self) -> i32 {

203

770001

        self.width

204

770001

205

206

    /// Returns the surface height.

207

    #[inline]

208

769997

    pub fn height(&self) -> i32 {

209

769997

        self.height

210

769997

211

212

    /// Returns the surface stride.

213

    #[inline]

214

325697

    pub fn stride(&self) -> isize {

215

325697

        self.stride

216

325697

217

218

219

impl ImageSurface<Shared> {

220

    /// Creates a `SharedImageSurface` from a unique `cairo::ImageSurface`.

221

///

222

    /// # Panics

223

    /// Panics if the surface format isn't `ARgb32` and if the surface is not unique, that is, its

224

    /// reference count isn't 1.

225

    #[inline]

226

4165

    pub fn wrap(

227

        surface: cairo::ImageSurface,

228

        surface_type: SurfaceType,

229

    ) -> Result<SharedImageSurface, cairo::Error> {

230

        // get_pixel() assumes ARgb32.

231

4165

        assert_eq!(surface.format(), cairo::Format::ARgb32);

232

233

        let reference_count =

234

4161

            unsafe { cairo::ffi::cairo_surface_get_reference_count(surface.to_raw_none()) };

235

4162

        assert_eq!(reference_count, 1);

236

237

4162

        let (width, height) = (surface.width(), surface.height());

238

239

        // Cairo allows zero-sized surfaces, but it does malloc(0), whose result

240

        // is implementation-defined.  So, we can't assume NonNull below.  This is

241

        // why we disallow zero-sized surfaces here.

242

4162

        if !(width > 0 && height > 0) {

243

            return Err(cairo::Error::InvalidSize);

244

245

246

4162

        surface.flush();

247

248

4162

        let data_ptr = NonNull::new(unsafe {

249

4162

            cairo::ffi::cairo_image_surface_get_data(surface.to_raw_none())

250

})

251

        .unwrap();

252

253

4161

        let stride = surface.stride() as isize;

254

255

4161

        Ok(SharedImageSurface {

256

4161

            surface,

257

            data_ptr,

258

            width,

259

            height,

260

            stride,

261

            surface_type,

262

            _state: PhantomData,

263

})

264

4161

265

266

    /// Creates a `SharedImageSurface` copying from a `cairo::ImageSurface`, even if it

267

    /// does not have a reference count of 1.

268

    #[inline]

269

301

    pub fn copy_from_surface(surface: &cairo::ImageSurface) -> Result<Self, cairo::Error> {

270

301

        let copy =

271

301

            cairo::ImageSurface::create(cairo::Format::ARgb32, surface.width(), surface.height())?;

272

273

274

301

            let cr = cairo::Context::new(&copy)?;

275

301

            cr.set_source_surface(surface, 0f64, 0f64)?;

276

602

            cr.paint()?;

277

301

278

279

301

        SharedImageSurface::wrap(copy, SurfaceType::SRgb)

280

301

281

282

    /// Creates an empty `SharedImageSurface` of the given size and `type`.

283

    #[inline]

284

9

    pub fn empty(width: i32, height: i32, surface_type: SurfaceType) -> Result<Self, cairo::Error> {

285

9

        let s = cairo::ImageSurface::create(cairo::Format::ARgb32, width, height)?;

286

287

9

        SharedImageSurface::wrap(s, surface_type)

288

9

289

290

    /// Converts this `SharedImageSurface` back into a Cairo image surface.

291

    #[inline]

292

410

    pub fn into_image_surface(self) -> Result<cairo::ImageSurface, cairo::Error> {

293

410

        let reference_count =

294

410

            unsafe { cairo::ffi::cairo_surface_get_reference_count(self.surface.to_raw_none()) };

295

296

410

        if reference_count == 1 {

297

408

            Ok(self.surface)

298

        } else {

299

            // If there are any other references, copy the underlying surface.

300

2

            self.copy_surface(IRect::from_size(self.width, self.height))

301

302

410

303

304

30

    pub fn from_image(

305

        image: &image::DynamicImage,

306

        content_type: Option<&str>,

307

        mime_data: Option<Vec<u8>>,

308

    ) -> Result<SharedImageSurface, cairo::Error> {

309

30

        let rgba_image = image.to_rgba8();

310

311

30

        let width = i32(rgba_image.width()).map_err(|_| cairo::Error::InvalidSize)?;

312

30

        let height = i32(rgba_image.height()).map_err(|_| cairo::Error::InvalidSize)?;

313

314

30

        let mut surf = ExclusiveImageSurface::new(width, height, SurfaceType::SRgb)?;

315

316

60

        rgba_image

317

            .rows()

318

30

            .zip(surf.rows_mut())

319

4147

            .flat_map(|(src_row, dest_row)| src_row.zip(dest_row.iter_mut()))

320

1390979

            .for_each(|(src, dest)| *dest = src.to_pixel().premultiply().to_cairo_argb());

321

322

30

        if let (Some(content_type), Some(bytes)) = (content_type, mime_data) {

323

30

            surf.surface.set_mime_data(content_type, bytes)?;

324

30

325

326

30

        surf.share()

327

30

328

329

    /// Returns `true` if the surface contains meaningful data only in the alpha channel.

330

    #[inline]

331

472

    fn is_alpha_only(&self) -> bool {

332

472

        self.surface_type == SurfaceType::AlphaOnly

333

472

334

335

    /// Returns the type of this surface.

336

    #[inline]

337

581

    pub fn surface_type(&self) -> SurfaceType {

338

581

        self.surface_type

339

581

340

341

    /// Retrieves the pixel value at the given coordinates.

342

    #[inline]

343

13810664

    pub fn get_pixel(&self, x: u32, y: u32) -> Pixel {

344

13810664

        assert!(x < self.width as u32);

345

13810664

        assert!(y < self.height as u32);

346

347

        #[allow(clippy::cast_ptr_alignment)]

348

        let value = unsafe {

349

27621328

            *(self

350

                .data_ptr

351

                .as_ptr()

352

13810664

                .offset(y as isize * self.stride + x as isize * 4) as *const u32)

353

};

354

355

13810664

        Pixel::from_u32(value)

356

13810664

357

358

    /// Retrieves the pixel value by offset into the pixel data array.

359

    #[inline]

360

98337775

    pub fn get_pixel_by_offset(&self, offset: isize) -> Pixel {

361

98337775

        assert!(offset < self.stride * self.height as isize);

362

363

        #[allow(clippy::cast_ptr_alignment)]

364

98337775

        let value = unsafe { *(self.data_ptr.as_ptr().offset(offset) as *const u32) };

365

98337775

        Pixel::from_u32(value)

366

98337775

367

368

    /// Calls `set_source_surface()` on the given Cairo context.

369

    #[inline]

370

109719

    pub fn set_as_source_surface(

371

        &self,

372

        cr: &cairo::Context,

373

        x: f64,

374

        y: f64,

375

    ) -> Result<(), cairo::Error> {

376

109719

        cr.set_source_surface(&self.surface, x, y)

377

109719

378

379

    /// Creates a Cairo surface pattern from the surface

380

109

    pub fn to_cairo_pattern(&self) -> cairo::SurfacePattern {

381

109

        cairo::SurfacePattern::create(&self.surface)

382

109

383

384

    /// Returns a new `cairo::ImageSurface` with the same contents as the one stored in this

385

    /// `SharedImageSurface` within the given bounds.

386

62

    fn copy_surface(&self, bounds: IRect) -> Result<cairo::ImageSurface, cairo::Error> {

387

62

        let output_surface =

388

62

            cairo::ImageSurface::create(cairo::Format::ARgb32, self.width, self.height)?;

389

390

62

        let cr = cairo::Context::new(&output_surface)?;

391

62

        let r = cairo::Rectangle::from(bounds);

392

62

        cr.rectangle(r.x(), r.y(), r.width(), r.height());

393

62

        cr.clip();

394

395

62

        cr.set_source_surface(&self.surface, 0f64, 0f64)?;

396

124

        cr.paint()?;

397

398

62

        Ok(output_surface)

399

62

400

401

    /// Scales the given surface by `x` and `y` into a surface `width`×`height` in size, clipped by

402

    /// `bounds`.

403

10

    pub fn scale_to(

404

        &self,

405

        width: i32,

406

        height: i32,

407

        bounds: IRect,

408

        x: f64,

409

        y: f64,

410

    ) -> Result<SharedImageSurface, cairo::Error> {

411

10

        let output_surface = cairo::ImageSurface::create(cairo::Format::ARgb32, width, height)?;

412

413

414

10

            let cr = cairo::Context::new(&output_surface)?;

415

10

            let r = cairo::Rectangle::from(bounds);

416

10

            cr.rectangle(r.x(), r.y(), r.width(), r.height());

417

10

            cr.clip();

418

419

10

            cr.scale(x, y);

420

10

            self.set_as_source_surface(&cr, 0.0, 0.0)?;

421

20

            cr.paint()?;

422

10

423

424

10

        SharedImageSurface::wrap(output_surface, self.surface_type)

425

10

426

427

    /// Returns a scaled version of a surface and bounds.

428

    #[inline]

429

5

    pub fn scale(

430

        &self,

431

        bounds: IRect,

432

        x: f64,

433

        y: f64,

434

    ) -> Result<(SharedImageSurface, IRect), cairo::Error> {

435

5

        let new_width = (f64::from(self.width) * x).ceil() as i32;

436

5

        let new_height = (f64::from(self.height) * y).ceil() as i32;

437

5

        let new_bounds = bounds.scale(x, y);

438

439

5

        Ok((

440

5

            self.scale_to(new_width, new_height, new_bounds, x, y)?,

441

            new_bounds,

442

))

443

5

444

445

    /// Returns a surface with black background and alpha channel matching this surface.

446

9207

    pub fn extract_alpha(&self, bounds: IRect) -> Result<SharedImageSurface, cairo::Error> {

447

9207

        let mut output_surface =

448

9207

            cairo::ImageSurface::create(cairo::Format::ARgb32, self.width, self.height)?;

449

450

9207

        let output_stride = output_surface.stride() as usize;

451

452

17

            let mut output_data = output_surface.data().unwrap();

453

454

508081

            for (x, y, Pixel { a, .. }) in Pixels::within(self, bounds) {

455

503469

                let output_pixel = Pixel {

456

                    r: 0,

457

                    g: 0,

458

                    b: 0,

459

a,

460

};

461

503469

                output_data.set_pixel(output_stride, output_pixel, x, y);

462

463

17

464

465

17

        SharedImageSurface::wrap(output_surface, SurfaceType::AlphaOnly)

466

17

467

468

    /// Returns a surface whose alpha channel for each pixel is equal to the

469

    /// luminance of that pixel's unpremultiplied RGB values.  The resulting

470

    /// surface's RGB values are not meanignful; only the alpha channel has

471

    /// useful luminance data.

472

///

473

    /// This is to get a mask suitable for use with cairo_mask_surface().

474

153127

    pub fn to_luminance_mask(&self) -> Result<SharedImageSurface, cairo::Error> {

475

153127

        let bounds = IRect::from_size(self.width, self.height);

476

477

        let mut output_surface =

478

153127

            cairo::ImageSurface::create(cairo::Format::ARgb32, self.width, self.height)?;

479

480

153127

        let stride = output_surface.stride() as usize;

481

482

57

            let mut data = output_surface.data().unwrap();

483

484

32700085

            for (x, y, pixel) in Pixels::within(self, bounds) {

485

32623493

                data.set_pixel(stride, pixel.to_luminance_mask(), x, y);

486

487

57

488

489

57

        SharedImageSurface::wrap(output_surface, self.surface_type)

490

57

491

492

    /// Returns a surface with pre-multiplication of color values undone.

493

///

494

    /// HACK: this is storing unpremultiplied pixels in an ARGB32 image surface (which is supposed

495

    /// to be premultiplied pixels).

496

1579

    pub fn unpremultiply(&self, bounds: IRect) -> Result<SharedImageSurface, cairo::Error> {

497

        // Unpremultiplication doesn't affect the alpha channel.

498

1579

        if self.is_alpha_only() {

499

1

            return Ok(self.clone());

500

501

502

        let mut output_surface =

503

1578

            cairo::ImageSurface::create(cairo::Format::ARgb32, self.width, self.height)?;

504

505

1578

        let stride = output_surface.stride() as usize;

506

507

6

            let mut data = output_surface.data().unwrap();

508

509

94385

            for (x, y, pixel) in Pixels::within(self, bounds) {

510

93427

                data.set_pixel(stride, pixel.unpremultiply(), x, y);

511

512

6

513

514

6

        SharedImageSurface::wrap(output_surface, self.surface_type)

515

7

516

517

    /// Converts the surface to the linear sRGB color space.

518

    #[inline]

519

373

    pub fn to_linear_rgb(&self, bounds: IRect) -> Result<SharedImageSurface, cairo::Error> {

520

373

        match self.surface_type {

521

92

            SurfaceType::LinearRgb | SurfaceType::AlphaOnly => Ok(self.clone()),

522

281

            _ => srgb::linearize_surface(self, bounds),

523

524

373

525

526

    /// Converts the surface to the sRGB color space.

527

    #[inline]

528

310

    pub fn to_srgb(&self, bounds: IRect) -> Result<SharedImageSurface, cairo::Error> {

529

310

        match self.surface_type {

530

83

            SurfaceType::SRgb | SurfaceType::AlphaOnly => Ok(self.clone()),

531

227

            _ => srgb::unlinearize_surface(self, bounds),

532

533

310

534

535

    /// Performs a convolution.

536

///

537

    /// Note that `kernel` is rotated 180 degrees.

538

///

539

    /// The `target` parameter determines the position of the kernel relative to each pixel of the

540

    /// image. The value of `(0, 0)` indicates that the top left pixel of the (180-degrees-rotated)

541

    /// kernel corresponds to the current pixel, and the rest of the kernel is to the right and

542

    /// bottom of the pixel. The value of `(cols / 2, rows / 2)` centers a kernel with an odd

543

    /// number of rows and columns.

544

///

545

    /// # Panics

546

    /// Panics if `kernel` has zero rows or columns.

547

21991

    pub fn convolve<R: Dim, C: Dim, S: Storage<f64, R, C>>(

548

        &self,

549

        bounds: IRect,

550

        target: (i32, i32),

551

        kernel: &Matrix<f64, R, C, S>,

552

        edge_mode: EdgeMode,

553

    ) -> Result<SharedImageSurface, cairo::Error> {

554

21991

        assert!(kernel.nrows() >= 1);

555

21991

        assert!(kernel.ncols() >= 1);

556

557

        let mut output_surface =

558

21991

            cairo::ImageSurface::create(cairo::Format::ARgb32, self.width, self.height)?;

559

560

21991

        let output_stride = output_surface.stride() as usize;

561

562

9

            let mut output_data = output_surface.data().unwrap();

563

564

9

            if self.is_alpha_only() {

565

                for (x, y, _pixel) in Pixels::within(self, bounds) {

566

                    let kernel_bounds = IRect::new(

567

                        x as i32 - target.0,

568

                        y as i32 - target.1,

569

                        x as i32 - target.0 + kernel.ncols() as i32,

570

                        y as i32 - target.1 + kernel.nrows() as i32,

571

);

572

573

                    let mut a = 0.0;

574

575

                    for (x, y, pixel) in

576

                        PixelRectangle::within(self, bounds, kernel_bounds, edge_mode)

577

578

                        let kernel_x = (kernel_bounds.x1 - x - 1) as usize;

579

                        let kernel_y = (kernel_bounds.y1 - y - 1) as usize;

580

                        let factor = kernel[(kernel_y, kernel_x)];

581

582

                        a += f64::from(pixel.a) * factor;

583

584

585

                    let convert = |x: f64| (clamp(x, 0.0, 255.0) + 0.5) as u8;

586

587

                    let output_pixel = Pixel {

588

                        r: 0,

589

                        g: 0,

590

                        b: 0,

591

                        a: convert(a),

592

};

593

594

                    output_data.set_pixel(output_stride, output_pixel, x, y);

595

596

            } else {

597

116441

                for (x, y, _pixel) in Pixels::within(self, bounds) {

598

116300

                    let kernel_bounds = IRect::new(

599

116502

                        x as i32 - target.0,

600

116502

                        y as i32 - target.1,

601

116502

                        x as i32 - target.0 + kernel.ncols() as i32,

602

116390

                        y as i32 - target.1 + kernel.nrows() as i32,

603

);

604

605

116685

                    let mut r = 0.0;

606

116685

                    let mut g = 0.0;

607

116685

                    let mut b = 0.0;

608

116685

                    let mut a = 0.0;

609

610

1145958

                    for (x, y, pixel) in

611

626162

                        PixelRectangle::within(self, bounds, kernel_bounds, edge_mode)

612

613

519520

                        let kernel_x = (kernel_bounds.x1 - x - 1) as usize;

614

519520

                        let kernel_y = (kernel_bounds.y1 - y - 1) as usize;

615

519520

                        let factor = kernel[(kernel_y, kernel_x)];

616

617

513670

                        r += f64::from(pixel.r) * factor;

618

513024

                        g += f64::from(pixel.g) * factor;

619

510576

                        b += f64::from(pixel.b) * factor;

620

508811

                        a += f64::from(pixel.a) * factor;

621

622

623

485399

                    let convert = |x: f64| (clamp(x, 0.0, 255.0) + 0.5) as u8;

624

625

116577

                    let output_pixel = Pixel {

626

116088

                        r: convert(r),

627

116592

                        g: convert(g),

628

116313

                        b: convert(b),

629

116297

                        a: convert(a),

630

};

631

632

116287

                    output_data.set_pixel(output_stride, output_pixel, x, y);

633

634

635

21991

636

637

9

        SharedImageSurface::wrap(output_surface, self.surface_type)

638

9

639

640

    /// Performs a horizontal or vertical box blur.

641

///

642

    /// The `target` parameter determines the position of the kernel relative to each pixel of the

643

    /// image. The value of `0` indicates that the first pixel of the kernel corresponds to the

644

    /// current pixel, and the rest of the kernel is to the right or bottom of the pixel. The value

645

    /// of `kernel_size / 2` centers a kernel with an odd size.

646

///

647

    /// # Panics

648

    /// Panics if `kernel_size` is `0` or if `target >= kernel_size`.

649

    // This is public (and not inlined into box_blur()) for the purpose of accessing it from the

650

    // benchmarks.

651

228

    pub fn box_blur_loop<B: BlurDirection, A: IsAlphaOnly>(

652

        &self,

653

        output_surface: &mut cairo::ImageSurface,

654

        bounds: IRect,

655

        kernel_size: usize,

656

        target: usize,

657

) {

658

228

        assert_ne!(kernel_size, 0);

659

228

        assert!(target < kernel_size);

660

228

        assert_eq!(self.is_alpha_only(), A::IS_ALPHA_ONLY);

661

662

663

            // The following code is needed for a parallel implementation of the blur loop. The

664

            // blurring is done either for each row or for each column of pixels, depending on the

665

            // value of `vertical`, independently of the others. Naturally, we want to run the

666

            // outer loop on a thread pool.

667

//

668

            // The case of `vertical == false` is simple since the input image slice can be

669

            // partitioned into chunks for each row of pixels and processed in parallel with rayon.

670

            // The case of `vertical == true`, however, is more involved because we can't just make

671

            // mutable slices for all pixel columns (they would be overlapping which is forbidden

672

            // by the aliasing rules).

673

//

674

            // This is where the following struct comes into play: it stores a sub-slice of the

675

            // pixel data and can be split at any row or column into two parts (similar to

676

            // slice::split_at_mut()).

677

            struct UnsafeSendPixelData<'a> {

678

                width: u32,

679

                height: u32,

680

                stride: isize,

681

                ptr: NonNull<u8>,

682

                _marker: PhantomData<&'a mut ()>,

683

684

685

            unsafe impl<'a> Send for UnsafeSendPixelData<'a> {}

686

687

            impl<'a> UnsafeSendPixelData<'a> {

688

                /// Creates a new `UnsafeSendPixelData`.

689

///

690

                /// # Safety

691

                /// You must call `cairo_surface_mark_dirty()` on the surface once all instances of

692

                /// `UnsafeSendPixelData` are dropped to make sure the pixel changes are committed

693

                /// to Cairo.

694

                #[inline]

695

228

                unsafe fn new(surface: &mut cairo::ImageSurface) -> Self {

696

228

                    assert_eq!(surface.format(), cairo::Format::ARgb32);

697

228

                    let ptr = surface.data().unwrap().as_mut_ptr();

698

699

228

                    Self {

700

228

                        width: surface.width() as u32,

701

228

                        height: surface.height() as u32,

702

228

                        stride: surface.stride() as isize,

703

228

                        ptr: NonNull::new(ptr).unwrap(),

704

                        _marker: PhantomData,

705

706

228

707

708

                /// Sets a pixel value at the given coordinates.

709

                #[inline]

710

7866580

                fn set_pixel(&mut self, pixel: Pixel, x: u32, y: u32) {

711

7866580

                    assert!(x < self.width);

712

7866580

                    assert!(y < self.height);

713

714

7866580

                    let value = pixel.to_u32();

715

716

                    #[allow(clippy::cast_ptr_alignment)]

717

                    unsafe {

718

15733160

                        let ptr = self

719

                            .ptr

720

                            .as_ptr()

721

7866580

                            .offset(y as isize * self.stride + x as isize * 4)

722

                            as *mut u32;

723

7866580

                        *ptr = value;

724

725

7866580

726

727

                /// Splits this `UnsafeSendPixelData` into two at the given row.

728

///

729

                /// The first one contains rows `0..index` (`index` not included) and the second one

730

                /// contains rows `index..height`.

731

                #[inline]

732

18591

                fn split_at_row(self, index: u32) -> (Self, Self) {

733

18591

                    assert!(index <= self.height);

734

735

18591

736

18591

                        UnsafeSendPixelData {

737

18591

                            width: self.width,

738

                            height: index,

739

18591

                            stride: self.stride,

740

18591

                            ptr: self.ptr,

741

                            _marker: PhantomData,

742

},

743

18591

                        UnsafeSendPixelData {

744

18591

                            width: self.width,

745

18591

                            height: self.height - index,

746

18591

                            stride: self.stride,

747

18591

                            ptr: NonNull::new(unsafe {

748

18591

                                self.ptr.as_ptr().offset(index as isize * self.stride)

749

})

750

                            .unwrap(),

751

                            _marker: PhantomData,

752

},

753

754

18591

755

756

                /// Splits this `UnsafeSendPixelData` into two at the given column.

757

///

758

                /// The first one contains columns `0..index` (`index` not included) and the second

759

                /// one contains columns `index..width`.

760

                #[inline]

761

20388

                fn split_at_column(self, index: u32) -> (Self, Self) {

762

20388

                    assert!(index <= self.width);

763

764

20388

765

20388

                        UnsafeSendPixelData {

766

                            width: index,

767

20388

                            height: self.height,

768

20388

                            stride: self.stride,

769

20388

                            ptr: self.ptr,

770

                            _marker: PhantomData,

771

},

772

20388

                        UnsafeSendPixelData {

773

20388

                            width: self.width - index,

774

20388

                            height: self.height,

775

20388

                            stride: self.stride,

776

20388

                            ptr: NonNull::new(unsafe {

777

20388

                                self.ptr.as_ptr().offset(index as isize * 4)

778

})

779

                            .unwrap(),

780

                            _marker: PhantomData,

781

},

782

783

20388

784

785

786

228

            let output_data = unsafe { UnsafeSendPixelData::new(output_surface) };

787

788

            // Shift is target into the opposite direction.

789

228

            let shift = (kernel_size - target) as i32;

790

228

            let target = target as i32;

791

792

            // Convert to f64 once since we divide by it.

793

228

            let kernel_size_f64 = kernel_size as f64;

794

17231998

            let compute = |x: u32| (f64::from(x) / kernel_size_f64 + 0.5) as u8;

795

796

            // Depending on `vertical`, we're blurring either horizontally line-by-line, or

797

            // vertically column-by-column. In the code below, the main axis is the axis along

798

            // which the blurring happens (so if `vertical` is false, the main axis is the

799

            // horizontal axis). The other axis is the outer loop axis. The code uses `i` and `j`

800

            // for the other axis and main axis coordinates, respectively.

801

228

            let (main_axis_min, main_axis_max, other_axis_min, other_axis_max) = if B::IS_VERTICAL {

802

111

                (bounds.y0, bounds.y1, bounds.x0, bounds.x1)

803

            } else {

804

117

                (bounds.x0, bounds.x1, bounds.y0, bounds.y1)

805

};

806

807

            // Helper function for getting the pixels.

808

9013533

            let pixel = |i, j| {

809

9013305

                let (x, y) = if B::IS_VERTICAL { (i, j) } else { (j, i) };

810

811

9013305

                self.get_pixel(x as u32, y as u32)

812

9013305

};

813

814

            // The following loop assumes the first row or column of `output_data` is the first row

815

            // or column inside `bounds`.

816

228

            let mut output_data = if B::IS_VERTICAL {

817

111

                output_data.split_at_column(bounds.x0 as u32).1

818

            } else {

819

117

                output_data.split_at_row(bounds.y0 as u32).1

820

};

821

822

456

            rayon::scope(|s| {

823

38979

                for i in other_axis_min..other_axis_max {

824

                    // Split off one row or column and launch its processing on another thread.

825

                    // Thanks to the initial split before the loop, there's no special case for the

826

                    // very first split.

827

77502

                    let (mut current, remaining) = if B::IS_VERTICAL {

828

20277

                        output_data.split_at_column(1)

829

                    } else {

830

18474

                        output_data.split_at_row(1)

831

};

832

833

38751

                    output_data = remaining;

834

835

79429

                    s.spawn(move |_| {

836

                        // Helper function for setting the pixels.

837

7517699

                        let mut set_pixel = |j, pixel| {

838

                            // We're processing rows or columns one-by-one, so the other coordinate

839

                            // is always 0.

840

7477021

                            let (x, y) = if B::IS_VERTICAL { (0, j) } else { (j, 0) };

841

7477021

                            current.set_pixel(pixel, x, y);

842

7477021

};

843

844

                        // The idea is that since all weights of the box blur kernel are equal, for

845

                        // each step along the main axis, instead of recomputing the full sum, we

846

                        // can take the previous sum, subtract the "oldest" pixel value and add the

847

                        // "newest" pixel value.

848

//

849

                        // The sum is u32 so that it can fit MAXIMUM_KERNEL_SIZE * 255.

850

40678

                        let mut sum_r = 0;

851

40678

                        let mut sum_g = 0;

852

40678

                        let mut sum_b = 0;

853

40678

                        let mut sum_a = 0;

854

855

                        // The whole sum needs to be computed for the first pixel. However, we know

856

                        // that values outside of bounds are transparent, so the loop starts on the

857

                        // first pixel in bounds.

858

260911

                        for j in main_axis_min..min(main_axis_max, main_axis_min + shift) {

859

220233

                            let Pixel { r, g, b, a } = pixel(i, j);

860

861

220233

                            if !A::IS_ALPHA_ONLY {

862

159903

                                sum_r += u32::from(r);

863

159903

                                sum_g += u32::from(g);

864

159903

                                sum_b += u32::from(b);

865

866

867

218255

                            sum_a += u32::from(a);

868

869

870

38700

                        set_pixel(

871

38700

                            main_axis_min as u32,

872

38700

                            Pixel {

873

38700

                                r: compute(sum_r),

874

38700

                                g: compute(sum_g),

875

38700

                                b: compute(sum_b),

876

38700

                                a: compute(sum_a),

877

},

878

);

879

880

                        // Now, go through all the other pixels.

881

//

882

                        // j - target - 1 >= main_axis_min

883

                        // j >= main_axis_min + target + 1

884

38700

                        let start_subtracting_at = main_axis_min + target + 1;

885

886

                        // j + shift - 1 < main_axis_max

887

                        // j < main_axis_max - shift + 1

888

38700

                        let stop_adding_at = main_axis_max - shift + 1;

889

890

6245949

                        for j in main_axis_min + 1..main_axis_max {

891

16876273

                            if j >= start_subtracting_at {

892

7937336

                                let old_pixel = pixel(i, j - target - 1);

893

894

7937336

                                if !A::IS_ALPHA_ONLY {

895

5269870

                                    sum_r -= u32::from(old_pixel.r);

896

5269870

                                    sum_g -= u32::from(old_pixel.g);

897

5269870

                                    sum_b -= u32::from(old_pixel.b);

898

899

900

6723990

                                sum_a -= u32::from(old_pixel.a);

901

902

903

15030490

                            if j < stop_adding_at {

904

7304899

                                let new_pixel = pixel(i, j + shift - 1);

905

906

7304899

                                if !A::IS_ALPHA_ONLY {

907

4979044

                                    sum_r += u32::from(new_pixel.r);

908

4979044

                                    sum_g += u32::from(new_pixel.g);

909

4979044

                                    sum_b += u32::from(new_pixel.b);

910

911

912

6627941

                                sum_a += u32::from(new_pixel.a);

913

914

915

6207249

                            set_pixel(

916

                                j as u32,

917

6207249

                                Pixel {

918

6207249

                                    r: compute(sum_r),

919

6207249

                                    g: compute(sum_g),

920

6207249

                                    b: compute(sum_b),

921

6207249

                                    a: compute(sum_a),

922

},

923

);

924

925

2692988

});

926

927

228

});

928

929

930

        // Don't forget to manually mark the surface as dirty (due to usage of

931

        // `UnsafeSendPixelData`).

932

228

        unsafe { cairo::ffi::cairo_surface_mark_dirty(output_surface.to_raw_none()) }

933

228

934

935

    /// Performs a horizontal or vertical box blur.

936

///

937

    /// The `target` parameter determines the position of the kernel relative to each pixel of the

938

    /// image. The value of `0` indicates that the first pixel of the kernel corresponds to the

939

    /// current pixel, and the rest of the kernel is to the right or bottom of the pixel. The value

940

    /// of `kernel_size / 2` centers a kernel with an odd size.

941

///

942

    /// # Panics

943

    /// Panics if `kernel_size` is `0` or if `target >= kernel_size`.

944

    #[inline]

945

228

    pub fn box_blur<B: BlurDirection>(

946

        &self,

947

        bounds: IRect,

948

        kernel_size: usize,

949

        target: usize,

950

    ) -> Result<SharedImageSurface, cairo::Error> {

951

228

        let mut output_surface =

952

228

            cairo::ImageSurface::create(cairo::Format::ARgb32, self.width, self.height)?;

953

954

228

        if self.is_alpha_only() {

955

69

            self.box_blur_loop::<B, AlphaOnly>(&mut output_surface, bounds, kernel_size, target);

956

        } else {

957

159

            self.box_blur_loop::<B, NotAlphaOnly>(&mut output_surface, bounds, kernel_size, target);

958

959

960

228

        SharedImageSurface::wrap(output_surface, self.surface_type)

961

228

962

963

    /// Fills the with a specified color.

964

    #[inline]

965

102

    pub fn flood(&self, bounds: IRect, color: Color) -> Result<SharedImageSurface, cairo::Error> {

966

102

        let output_surface =

967

102

            cairo::ImageSurface::create(cairo::Format::ARgb32, self.width, self.height)?;

968

969

102

        let rgba = color_to_rgba(&color);

970

971

34

        if rgba.alpha.unwrap_or(0.0) > 0.0 {

972

34

            let cr = cairo::Context::new(&output_surface)?;

973

34

            let r = cairo::Rectangle::from(bounds);

974

34

            cr.rectangle(r.x(), r.y(), r.width(), r.height());

975

34

            cr.clip();

976

977

34

            set_source_color_on_cairo(&cr, &color);

978

136

            cr.paint()?;

979

34

980

981

68

        SharedImageSurface::wrap(output_surface, self.surface_type)

982

34

983

984

    /// Offsets the image of the specified amount.

985

    #[inline]

986

68

    pub fn offset(

987

        &self,

988

        bounds: Rect,

989

        dx: f64,

990

        dy: f64,

991

    ) -> Result<SharedImageSurface, cairo::Error> {

992

68

        let output_surface =

993

68

            cairo::ImageSurface::create(cairo::Format::ARgb32, self.width, self.height)?;

994

995

        // output_bounds contains all pixels within bounds,

996

        // for which (x - ox) and (y - oy) also lie within bounds.

997

68

        if let Some(output_bounds) = bounds.translate((dx, dy)).intersection(&bounds) {

998

22

            let cr = cairo::Context::new(&output_surface)?;

999

22

            let r = cairo::Rectangle::from(output_bounds);

1000

22

            cr.rectangle(r.x(), r.y(), r.width(), r.height());

1001

22

            cr.clip();

1002

1003

22

            self.set_as_source_surface(&cr, dx, dy)?;

1004

90

            cr.paint()?;

1005

22

1006

1007

46

        SharedImageSurface::wrap(output_surface, self.surface_type)

1008

24

1009

1010

    /// Returns a new surface of the same size, with the contents of the

1011

    /// specified image, optionally transformed to match a given box

1012

    #[inline]

1013

280

    pub fn paint_image(

1014

        &self,

1015

        bounds: Rect,

1016

        image: &SharedImageSurface,

1017

        rect: Option<Rect>,

1018

        interpolation: Interpolation,

1019

    ) -> Result<SharedImageSurface, cairo::Error> {

1020

280

        let output_surface =

1021

280

            cairo::ImageSurface::create(cairo::Format::ARgb32, self.width, self.height)?;

1022

1023

280

        if rect.is_none() || !rect.unwrap().is_empty() {

1024

25

            let cr = cairo::Context::new(&output_surface)?;

1025

148

            let r = cairo::Rectangle::from(bounds);

1026

66

            cr.rectangle(r.x(), r.y(), r.width(), r.height());

1027

66

            cr.clip();

1028

1029

66

            image.set_as_source_surface(&cr, 0f64, 0f64)?;

1030

1031

66

            if let Some(rect) = rect {

1032

41

                let mut matrix = cairo::Matrix::new(

1033

41

                    rect.width() / f64::from(image.width()),

1034

                    0.0,

1035

                    0.0,

1036

41

                    rect.height() / f64::from(image.height()),

1037

41

                    rect.x0,

1038

41

                    rect.y0,

1039

);

1040

41

                matrix.invert();

1041

1042

41

                cr.source().set_matrix(matrix);

1043

41

                cr.source().set_filter(cairo::Filter::from(interpolation));

1044

1045

1046

305

            cr.paint()?;

1047

66

1048

1049

91

        SharedImageSurface::wrap(output_surface, image.surface_type)

1050

66

1051

1052

    /// Creates a new surface with the size and content specified in `bounds`

1053

///

1054

    /// # Panics

1055

    /// Panics if `bounds` is an empty rectangle, since `SharedImageSurface` cannot

1056

    /// represent zero-sized images.

1057

    #[inline]

1058

1

    pub fn tile(&self, bounds: IRect) -> Result<SharedImageSurface, cairo::Error> {

1059

        // Cairo lets us create zero-sized surfaces, but the call to SharedImageSurface::wrap()

1060

        // below will panic in that case.  So, disallow requesting a zero-sized subregion.

1061

1

        assert!(!bounds.is_empty());

1062

1063

        let output_surface =

1064

1

            cairo::ImageSurface::create(cairo::Format::ARgb32, bounds.width(), bounds.height())?;

1065

1066

1067

1

            let cr = cairo::Context::new(&output_surface)?;

1068

1

            self.set_as_source_surface(&cr, f64::from(-bounds.x0), f64::from(-bounds.y0))?;

1069

2

            cr.paint()?;

1070

1

1071

1072

1

        SharedImageSurface::wrap(output_surface, self.surface_type)

1073

1

1074

1075

    /// Returns a new surface of the same size, with the contents of the specified

1076

    /// image repeated to fill the bounds and starting from the given position.

1077

    #[inline]

1078

1

    pub fn paint_image_tiled(

1079

        &self,

1080

        bounds: IRect,

1081

        image: &SharedImageSurface,

1082

        x: i32,

1083

        y: i32,

1084

    ) -> Result<SharedImageSurface, cairo::Error> {

1085

1

        let output_surface =

1086

1

            cairo::ImageSurface::create(cairo::Format::ARgb32, self.width, self.height)?;

1087

1088

1089

1

            let cr = cairo::Context::new(&output_surface)?;

1090

1091

1

            let ptn = image.to_cairo_pattern();

1092

1

            ptn.set_extend(cairo::Extend::Repeat);

1093

1

            let mut mat = cairo::Matrix::identity();

1094

1

            mat.translate(f64::from(-x), f64::from(-y));

1095

1

            ptn.set_matrix(mat);

1096

1097

1

            let r = cairo::Rectangle::from(bounds);

1098

1

            cr.rectangle(r.x(), r.y(), r.width(), r.height());

1099

1

            cr.clip();

1100

1101

1

            cr.set_source(&ptn)?;

1102

2

            cr.paint()?;

1103

1

1104

1105

1

        SharedImageSurface::wrap(output_surface, image.surface_type)

1106

1

1107

1108

    /// Performs the combination of two input surfaces using Porter-Duff

1109

    /// compositing operators.

1110

///

1111

    /// # Panics

1112

    /// Panics if the two surface types are not compatible.

1113

    #[inline]

1114

60

    pub fn compose(

1115

        &self,

1116

        other: &SharedImageSurface,

1117

        bounds: IRect,

1118

        operator: Operator,

1119

    ) -> Result<SharedImageSurface, cairo::Error> {

1120

60

        let output_surface = other.copy_surface(bounds)?;

1121

1122

1123

60

            let cr = cairo::Context::new(&output_surface)?;

1124

60

            let r = cairo::Rectangle::from(bounds);

1125

60

            cr.rectangle(r.x(), r.y(), r.width(), r.height());

1126

60

            cr.clip();

1127

1128

60

            self.set_as_source_surface(&cr, 0.0, 0.0)?;

1129

60

            cr.set_operator(operator.into());

1130

120

            cr.paint()?;

1131

60

1132

1133

60

        SharedImageSurface::wrap(

1134

60

            output_surface,

1135

60

            self.surface_type.combine(other.surface_type),

1136

60

1137

60

1138

1139

    /// Performs the combination of two input surfaces.

1140

///

1141

    /// Each pixel of the resulting image is computed using the following formula:

1142

    /// `res = k1*i1*i2 + k2*i1 + k3*i2 + k4`

1143

///

1144

    /// # Panics

1145

    /// Panics if the two surface types are not compatible.

1146

    #[inline]

1147

12

    pub fn compose_arithmetic(

1148

        &self,

1149

        other: &SharedImageSurface,

1150

        bounds: IRect,

1151

        k1: f64,

1152

        k2: f64,

1153

        k3: f64,

1154

        k4: f64,

1155

    ) -> Result<SharedImageSurface, cairo::Error> {

1156

24

        let mut output_surface = ExclusiveImageSurface::new(

1157

12

            self.width,

1158

12

            self.height,

1159

12

            self.surface_type.combine(other.surface_type),

1160

)?;

1161

1162

12

        composite_arithmetic(self, other, &mut output_surface, bounds, k1, k2, k3, k4);

1163

1164

12

        output_surface.share()

1165

12

1166

1167

9

    pub fn rows(&self) -> Rows<'_> {

1168

9

        Rows {

1169

            surface: self,

1170

            next_row: 0,

1171

1172

9

1173

1174

1175

impl<'a> Iterator for Rows<'a> {

1176

    type Item = &'a [CairoARGB];

1177

1178

4340

    fn next(&mut self) -> Option<Self::Item> {

1179

4340

        if self.next_row == self.surface.height {

1180

            return None;

1181

1182

1183

4340

        let row = self.next_row;

1184

1185

4340

        self.next_row += 1;

1186

1187

        // SAFETY: this code assumes that cairo image surface data is correctly

1188

        // aligned for u32. This assumption is justified by the Cairo docs,

1189

        // which say this:

1190

//

1191

        // https://cairographics.org/manual/cairo-Image-Surfaces.html#cairo-image-surface-create-for-data

1192

//

1193

        // > This pointer must be suitably aligned for any kind of variable,

1194

        // > (for example, a pointer returned by malloc).

1195

        unsafe {

1196

8680

            let row_ptr: *const u8 = self

1197

                .surface

1198

                .data_ptr

1199

                .as_ptr()

1200

4340

                .offset(row as isize * self.surface.stride);

1201

            let row_of_u32: &[u32] =

1202

4340

                slice::from_raw_parts(row_ptr as *const u32, self.surface.width as usize);

1203

4340

            let pixels = row_of_u32.as_cairo_argb();

1204

4340

            assert!(pixels.len() == self.surface.width as usize);

1205

4340

            Some(pixels)

1206

1207

4340

1208

1209

1210

impl<'a> Iterator for RowsMut<'a> {

1211

    type Item = &'a mut [CairoARGB];

1212

1213

4147

    fn next(&mut self) -> Option<Self::Item> {

1214

4147

        if self.next_row == self.height {

1215

            return None;

1216

1217

1218

4147

        let row = self.next_row as usize;

1219

1220

4147

        self.next_row += 1;

1221

1222

        // SAFETY: this code assumes that cairo image surface data is correctly

1223

        // aligned for u32. This assumption is justified by the Cairo docs,

1224

        // which say this:

1225

//

1226

        // https://cairographics.org/manual/cairo-Image-Surfaces.html#cairo-image-surface-create-for-data

1227

//

1228

        // > This pointer must be suitably aligned for any kind of variable,

1229

        // > (for example, a pointer returned by malloc).

1230

        unsafe {

1231

            // We do this with raw pointers, instead of re-slicing the &mut self.data[....],

1232

            // because with the latter we can't synthesize an appropriate lifetime for

1233

            // the return value.

1234

1235

4147

            let data_ptr = self.data.as_mut_ptr();

1236

4147

            let row_ptr: *mut u8 = data_ptr.offset(row as isize * self.stride as isize);

1237

            let row_of_u32: &mut [u32] =

1238

4147

                slice::from_raw_parts_mut(row_ptr as *mut u32, self.width as usize);

1239

4147

            let pixels = row_of_u32.as_cairo_argb_mut();

1240

4147

            assert!(pixels.len() == self.width as usize);

1241

4147

            Some(pixels)

1242

1243

4147

1244

1245

1246

/// Performs the arithmetic composite operation. Public for benchmarking.

1247

#[inline]

1248

12

pub fn composite_arithmetic(

1249

    surface1: &SharedImageSurface,

1250

    surface2: &SharedImageSurface,

1251

    output_surface: &mut ExclusiveImageSurface,

1252

    bounds: IRect,

1253

    k1: f64,

1254

    k2: f64,

1255

    k3: f64,

1256

    k4: f64,

1257

) {

1258

24

    output_surface.modify(&mut |data, stride| {

1259

139011

        for (x, y, pixel, pixel_2) in

1260

277986

            Pixels::within(surface1, bounds).map(|(x, y, p)| (x, y, p, surface2.get_pixel(x, y)))

1261

1262

138999

            let i1a = f64::from(pixel.a) / 255f64;

1263

138999

            let i2a = f64::from(pixel_2.a) / 255f64;

1264

138999

            let oa = k1 * i1a * i2a + k2 * i1a + k3 * i2a + k4;

1265

138999

            let oa = clamp(oa, 0f64, 1f64);

1266

1267

            // Contents of image surfaces are transparent by default, so if the resulting pixel is

1268

            // transparent there's no need to do anything.

1269

138999

            if oa > 0f64 {

1270

365076

                let compute = |i1, i2| {

1271

273098

                    let i1 = f64::from(i1) / 255f64;

1272

273098

                    let i2 = f64::from(i2) / 255f64;

1273

1274

273098

                    let o = k1 * i1 * i2 + k2 * i1 + k3 * i2 + k4;

1275

273098

                    let o = clamp(o, 0f64, oa);

1276

1277

273098

                    ((o * 255f64) + 0.5) as u8

1278

273098

};

1279

1280

91978

                let output_pixel = Pixel {

1281

91978

                    r: compute(pixel.r, pixel_2.r),

1282

91978

                    g: compute(pixel.g, pixel_2.g),

1283

91978

                    b: compute(pixel.b, pixel_2.b),

1284

91978

                    a: ((oa * 255f64) + 0.5) as u8,

1285

};

1286

1287

91978

                data.set_pixel(stride, output_pixel, x, y);

1288

1289

1290

12

});

1291

12

1292

1293

impl ImageSurface<Exclusive> {

1294

    #[inline]

1295

753

    pub fn new(

1296

        width: i32,

1297

        height: i32,

1298

        surface_type: SurfaceType,

1299

    ) -> Result<ExclusiveImageSurface, cairo::Error> {

1300

753

        let surface = cairo::ImageSurface::create(cairo::Format::ARgb32, width, height)?;

1301

1302

753

        let (width, height) = (surface.width(), surface.height());

1303

1304

        // Cairo allows zero-sized surfaces, but it does malloc(0), whose result

1305

        // is implementation-defined.  So, we can't assume NonNull below.  This is

1306

        // why we disallow zero-sized surfaces here.

1307

753

        if !(width > 0 && height > 0) {

1308

            return Err(cairo::Error::InvalidSize);

1309

1310

1311

753

        let data_ptr = NonNull::new(unsafe {

1312

753

            cairo::ffi::cairo_image_surface_get_data(surface.to_raw_none())

1313

})

1314

        .unwrap();

1315

1316

753

        let stride = surface.stride() as isize;

1317

1318

753

        Ok(ExclusiveImageSurface {

1319

753

            surface,

1320

            data_ptr,

1321

            width,

1322

            height,

1323

            stride,

1324

            surface_type,

1325

            _state: PhantomData,

1326

})

1327

753

1328

1329

    #[inline]

1330

753

    pub fn share(self) -> Result<SharedImageSurface, cairo::Error> {

1331

753

        SharedImageSurface::wrap(self.surface, self.surface_type)

1332

753

1333

1334

    /// Raw access to the image data as a slice

1335

    #[inline]

1336

697

    pub fn data(&mut self) -> cairo::ImageSurfaceData<'_> {

1337

697

        self.surface.data().unwrap()

1338

697

1339

1340

    /// Modify the image data

1341

    #[inline]

1342

609

    pub fn modify(&mut self, draw_fn: &mut dyn FnMut(&mut cairo::ImageSurfaceData<'_>, usize)) {

1343

609

        let stride = self.stride() as usize;

1344

609

        let mut data = self.data();

1345

1346

609

        draw_fn(&mut data, stride)

1347

609

1348

1349

    /// Draw on the surface using cairo

1350

    #[inline]

1351

25

    pub fn draw(

1352

        &mut self,

1353

        draw_fn: &mut dyn FnMut(cairo::Context) -> Result<(), InternalRenderingError>,

1354

    ) -> Result<(), InternalRenderingError> {

1355

25

        let cr = cairo::Context::new(&self.surface)?;

1356

25

        draw_fn(cr)

1357

25

1358

1359

30

    pub fn rows_mut(&mut self) -> RowsMut<'_> {

1360

30

        let width = self.surface.width();

1361

30

        let height = self.surface.height();

1362

30

        let stride = self.surface.stride();

1363

1364

30

        let data = self.surface.data().unwrap();

1365

1366

30

        RowsMut {

1367

            width,

1368

            height,

1369

            stride,

1370

            data,

1371

            next_row: 0,

1372

1373

30

1374

1375

1376

impl From<Operator> for cairo::Operator {

1377

60

    fn from(op: Operator) -> cairo::Operator {

1378

        use cairo::Operator as Cairo;

1379

        use Operator::*;

1380

1381

60

        match op {

1382

29

            Over => Cairo::Over,

1383

18

            In => Cairo::In,

1384

3

            Out => Cairo::Out,

1385

2

            Atop => Cairo::Atop,

1386

2

            Xor => Cairo::Xor,

1387

3

            Multiply => Cairo::Multiply,

1388

1

            Screen => Cairo::Screen,

1389

1

            Darken => Cairo::Darken,

1390

1

            Lighten => Cairo::Lighten,

1391

            Overlay => Cairo::Overlay,

1392

            ColorDodge => Cairo::ColorDodge,

1393

            ColorBurn => Cairo::ColorBurn,

1394

            HardLight => Cairo::HardLight,

1395

            SoftLight => Cairo::SoftLight,

1396

            Difference => Cairo::Difference,

1397

            Exclusion => Cairo::Exclusion,

1398

            HslHue => Cairo::HslHue,

1399

            HslSaturation => Cairo::HslSaturation,

1400

            HslColor => Cairo::HslColor,

1401

            HslLuminosity => Cairo::HslLuminosity,

1402

1403

60

1404

1405

1406

#[cfg(test)]

1407

mod tests {

1408

    use super::*;

1409

    use crate::surface_utils::iterators::Pixels;

1410

1411

    #[test]

1412

2

    fn test_extract_alpha() {

1413

        const WIDTH: i32 = 32;

1414

        const HEIGHT: i32 = 64;

1415

1416

1

        let bounds = IRect::new(8, 24, 16, 48);

1417

1

        let full_bounds = IRect::from_size(WIDTH, HEIGHT);

1418

1419

1

        let mut surface = ExclusiveImageSurface::new(WIDTH, HEIGHT, SurfaceType::SRgb).unwrap();

1420

1421

        // Fill the surface with some data.

1422

1423

1

            let mut data = surface.data();

1424

1425

1

            let mut counter = 0u16;

1426

8193

            for x in data.iter_mut() {

1427

8192

                *x = counter as u8;

1428

8192

                counter = (counter + 1) % 256;

1429

1430

1

1431

1432

1

        let surface = surface.share().unwrap();

1433

1

        let alpha = surface.extract_alpha(bounds).unwrap();

1434

1435

2049

        for (x, y, p, pa) in

1436

4097

            Pixels::within(&surface, full_bounds).map(|(x, y, p)| (x, y, p, alpha.get_pixel(x, y)))

1437

1438

2048

            assert_eq!(pa.r, 0);

1439

2048

            assert_eq!(pa.g, 0);

1440

2048

            assert_eq!(pa.b, 0);

1441

1442

2048

            if !bounds.contains(x as i32, y as i32) {

1443

1856

                assert_eq!(pa.a, 0);

1444

            } else {

1445

192

                assert_eq!(pa.a, p.a);

1446

1447

1448

2

1449