experimental/graphite/src/PaintParams.h

/*
 * Copyright 2022 Google LLC
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef skgpu_PaintParams_DEFINED
#define skgpu_PaintParams_DEFINED

#include "include/core/SkColor.h"
#include "include/core/SkPaint.h"

enum class SkBackend : uint8_t;
class SkPaintParamsKey;
class SkShader;
class SkShaderCodeDictionary;
class SkUniformBlock;

namespace skgpu {

// TBD: If occlusion culling is eliminated as a phase, we can easily move the paint conversion
// back to Device when the command is recorded (similar to SkPaint -> GrPaint), and then
// PaintParams is not required as an intermediate representation.
// NOTE: Only represents the shading state of an SkPaint. Style and complex effects (mask filters,
// image filters, path effects) must be handled higher up. AA is not tracked since everything is
// assumed to be anti-aliased.
class PaintParams {
public:
    PaintParams(const SkColor4f& color, sk_sp<SkBlender>, sk_sp<SkShader>);
    explicit PaintParams(const SkPaint&);

    PaintParams(const PaintParams&);
    ~PaintParams();

    PaintParams& operator=(const PaintParams&);

    SkColor4f color() const { return fColor; }

    skstd::optional<SkBlendMode> asBlendMode() const;
    SkBlender* blender() const { return fBlender.get(); }
    sk_sp<SkBlender> refBlender() const;

    SkShader* shader() const { return fShader.get(); }
    sk_sp<SkShader> refShader() const;

    void toKey(SkShaderCodeDictionary*,
               SkBackend,
               SkPaintParamsKey*,
               SkUniformBlock*) const;

private:
    SkColor4f        fColor;
    sk_sp<SkBlender> fBlender; // A nullptr here means SrcOver blending
    sk_sp<SkShader>  fShader; // For now only use SkShader::asAGradient() when converting to GPU
    // TODO: Will also store ColorFilter, dither, and any extra shader from an
    // active clipShader().
};

} // namespace skgpu

#endif // skgpu_PaintParams_DEFINED