skia_utils.h | Explore in Territory

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 *
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 * modification, are permitted provided that the following conditions are
 * met:
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 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

// All of the functions in this file should move to new homes and this file
// should be deleted.

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_GRAPHICS_SKIA_SKIA_UTILS_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_GRAPHICS_SKIA_SKIA_UTILS_H_

#include <utility>

#include "base/check_op.h"
#include "base/notreached.h"
#include "cc/paint/paint_canvas.h"
#include "third_party/blink/renderer/platform/graphics/graphics_types.h"
#include "third_party/blink/renderer/platform/graphics/image.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/transforms/affine_transform.h"
#include "third_party/blink/renderer/platform/wtf/cross_thread_copier.h"
#include "third_party/blink/renderer/platform/wtf/math_extras.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "third_party/skia/include/core/SkCanvas.h"
#include "third_party/skia/include/core/SkColor.h"
#include "third_party/skia/include/core/SkData.h"
#include "third_party/skia/include/core/SkPoint.h"
#include "third_party/skia/include/core/SkRefCnt.h"
#include "third_party/skia/include/core/SkScalar.h"

namespace blink {

/**** constants ****/

enum { … };

bool PLATFORM_EXPORT IsValidImageSize(const gfx::Size&);

SkBlendMode PLATFORM_EXPORT
    WebCoreCompositeToSkiaComposite(CompositeOperator,
                                    BlendMode = BlendMode::kNormal);
SkBlendMode PLATFORM_EXPORT WebCoreBlendModeToSkBlendMode(BlendMode);

std::pair<CompositeOperator, BlendMode> PLATFORM_EXPORT
CompositeAndBlendOpsFromSkBlendMode(SkBlendMode sk_blend_mode);

// Multiply a color's alpha channel by an additional alpha factor where
// alpha is in the range [0, 1].
SkColor PLATFORM_EXPORT ScaleAlpha(SkColor, float);

bool PLATFORM_EXPORT
ApproximatelyEqualSkColorSpaces(sk_sp<SkColorSpace> src_color_space,
                                sk_sp<SkColorSpace> dst_color_space);

// Skia has problems when passed infinite, etc floats, filter them to 0.
inline SkScalar WebCoreFloatToSkScalar(float f) { … }

inline SkScalar WebCoreDoubleToSkScalar(double d) { … }

inline bool WebCoreFloatNearlyEqual(float a, float b) { … }

inline SkPathFillType WebCoreWindRuleToSkFillType(WindRule rule) { … }

inline WindRule SkFillTypeToWindRule(SkPathFillType fill_type) { … }

inline SkPoint FloatPointToSkPoint(const gfx::PointF& point) { … }

SkMatrix PLATFORM_EXPORT AffineTransformToSkMatrix(const AffineTransform&);
SkM44 PLATFORM_EXPORT AffineTransformToSkM44(const AffineTransform&);

bool NearlyIntegral(float value);

InterpolationQuality ComputeInterpolationQuality(float src_width,
                                                 float src_height,
                                                 float dest_width,
                                                 float dest_height,
                                                 bool is_data_complete = true);

// Technically, this is driven by the CSS/Canvas2D specs and unrelated to Skia.
// It should probably live in the CSS layer, but the notion of a "blur radius"
// leaks into platform/graphics currently (ideally we should only deal with
// sigma at this level).
// TODO(fmalita): find a better home for this helper.
inline float BlurRadiusToStdDev(float radius) { … }

void PLATFORM_EXPORT DrawPlatformFocusRing(const SkRRect&,
                                           cc::PaintCanvas*,
                                           SkColor4f,
                                           float width);
void PLATFORM_EXPORT DrawPlatformFocusRing(const SkPath&,
                                           cc::PaintCanvas*,
                                           SkColor4f,
                                           float width,
                                           float corner_radius);

inline SkCanvas::SrcRectConstraint WebCoreClampingModeToSkiaRectConstraint(
    Image::ImageClampingMode clamp_mode) { … }

// Attempts to allocate an SkData on the PartitionAlloc buffer partition.
// If this fails (e.g. due to low memory), returns a null sk_sp<SkData> instead.
// Otherwise, the returned buffer is guaranteed to be zero-filled.
PLATFORM_EXPORT sk_sp<SkData> TryAllocateSkData(size_t size);

// Skia's smart pointer APIs are preferable over their legacy raw pointer
// counterparts.
//
// General guidelines
//
// When receiving ref counted objects from Skia:
//
//   1) Use sk_sp-based Skia factories if available (e.g. SkShader::MakeFoo()
//      instead of SkShader::CreateFoo()).
//   2) Use sk_sp<T> locals for all objects.
//
// When passing ref counted objects to Skia:
//
//   1) Use sk_sp-based Skia APIs when available (e.g.
//      SkPaint::setShader(sk_sp<SkShader>) instead of
//      SkPaint::setShader(SkShader*)).
//   2) If object ownership is being passed to Skia, use std::move(sk_sp<T>).
//
// Example (creating a SkShader and setting it on SkPaint):
//
// a) ownership transferred
//
//     // using Skia smart pointer locals
//     sk_sp<SkShader> shader = SkShader::MakeFoo(...);
//     paint.setShader(std::move(shader));
//
//     // using no locals
//     paint.setShader(SkShader::MakeFoo(...));
//
// b) shared ownership
//
//     sk_sp<SkShader> shader = SkShader::MakeFoo(...);
//     paint.setShader(shader);

}  // namespace blink

namespace WTF {

// We define CrossThreadCopier<SKBitMap> here because we cannot include skia
// headers in platform/wtf.
template <>
struct CrossThreadCopier<SkBitmap> { … };

}  // namespace WTF

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_GRAPHICS_SKIA_SKIA_UTILS_H_
chromium/third_party/blink/renderer/platform/graphics/skia/skia_utils.h
