The Tor Browser: comparison gfx/skia/trunk/include/gpu/GrPaint.h

--1:000000000000
+:1f83b83f78ee
+/*
+* Copyright 2011 Google Inc.
+*
+* Use of this source code is governed by a BSD-style license that can be
+* found in the LICENSE file.
+*/
+#ifndef GrPaint_DEFINED
+#define GrPaint_DEFINED
+#include "GrColor.h"
+#include "GrEffectStage.h"
+#include "SkXfermode.h"
+/**
+* The paint describes how color and coverage are computed at each pixel by GrContext draw
+* functions and the how color is blended with the destination pixel.
+*
+* The paint allows installation of custom color and coverage stages. New types of stages are
+* created by subclassing GrEffect.
+*
+* The primitive color computation starts with the color specified by setColor(). This color is the
+* input to the first color stage. Each color stage feeds its output to the next color stage. The
+* final color stage's output color is input to the color filter specified by
+* setXfermodeColorFilter which produces the final source color, S.
+*
+* Fractional pixel coverage follows a similar flow. The coverage is initially the value specified
+* by setCoverage(). This is input to the first coverage stage. Coverage stages are chained
+* together in the same manner as color stages. The output of the last stage is modulated by any
+* fractional coverage produced by anti-aliasing. This last step produces the final coverage, C.
+*
+* setBlendFunc() specifies blending coefficients for S (described above) and D, the initial value
+* of the destination pixel, labeled Bs and Bd respectively. The final value of the destination
+* pixel is then D' = (1-C)*D + C*(Bd*D + Bs*S).
+*
+* Note that the coverage is applied after the blend. This is why they are computed as distinct
+* values.
+*
+* TODO: Encapsulate setXfermodeColorFilter in a GrEffect and remove from GrPaint.
+*/
+class GrPaint {
+public:
+GrPaint() { this->reset(); }
+GrPaint(const GrPaint& paint) { *this = paint; }
+~GrPaint() {}
+/**
+* Sets the blending coefficients to use to blend the final primitive color with the
+* destination color. Defaults to kOne for src and kZero for dst (i.e. src mode).
+*/
+void setBlendFunc(GrBlendCoeff srcCoeff, GrBlendCoeff dstCoeff) {
+fSrcBlendCoeff = srcCoeff;
+fDstBlendCoeff = dstCoeff;
+}
+GrBlendCoeff getSrcBlendCoeff() const { return fSrcBlendCoeff; }
+GrBlendCoeff getDstBlendCoeff() const { return fDstBlendCoeff; }
+/**
+* The initial color of the drawn primitive. Defaults to solid white.
+*/
+void setColor(GrColor color) { fColor = color; }
+GrColor getColor() const { return fColor; }
+/**
+* Applies fractional coverage to the entire drawn primitive. Defaults to 0xff.
+*/
+void setCoverage(uint8_t coverage) { fCoverage = coverage; }
+uint8_t getCoverage() const { return fCoverage; }
+/**
+* Should primitives be anti-aliased or not. Defaults to false.
+*/
+void setAntiAlias(bool aa) { fAntiAlias = aa; }
+bool isAntiAlias() const { return fAntiAlias; }
+/**
+* Should dithering be applied. Defaults to false.
+*/
+void setDither(bool dither) { fDither = dither; }
+bool isDither() const { return fDither; }
+/**
+* Appends an additional color effect to the color computation.
+*/
+const GrEffectRef* addColorEffect(const GrEffectRef* effect, int attr0 = -1, int attr1 = -1) {
+SkASSERT(NULL != effect);
+if (!(*effect)->willUseInputColor()) {
+fColorStages.reset();
+}
+SkNEW_APPEND_TO_TARRAY(&fColorStages, GrEffectStage, (effect, attr0, attr1));
+return effect;
+}
+/**
+* Appends an additional coverage effect to the coverage computation.
+*/
+const GrEffectRef* addCoverageEffect(const GrEffectRef* effect, int attr0 = -1, int attr1 = -1) {
+SkASSERT(NULL != effect);
+if (!(*effect)->willUseInputColor()) {
+fCoverageStages.reset();
+}
+SkNEW_APPEND_TO_TARRAY(&fCoverageStages, GrEffectStage, (effect, attr0, attr1));
+return effect;
+}
+/**
+* Helpers for adding color or coverage effects that sample a texture. The matrix is applied
+* to the src space position to compute texture coordinates.
+*/
+void addColorTextureEffect(GrTexture* texture, const SkMatrix& matrix);
+void addCoverageTextureEffect(GrTexture* texture, const SkMatrix& matrix);
+void addColorTextureEffect(GrTexture* texture,
+const SkMatrix& matrix,
+const GrTextureParams& params);
+void addCoverageTextureEffect(GrTexture* texture,
+const SkMatrix& matrix,
+const GrTextureParams& params);
+int numColorStages() const { return fColorStages.count(); }
+int numCoverageStages() const { return fCoverageStages.count(); }
+int numTotalStages() const { return this->numColorStages() + this->numCoverageStages(); }
+const GrEffectStage& getColorStage(int s) const { return fColorStages[s]; }
+const GrEffectStage& getCoverageStage(int s) const { return fCoverageStages[s]; }
+GrPaint& operator=(const GrPaint& paint) {
+fSrcBlendCoeff = paint.fSrcBlendCoeff;
+fDstBlendCoeff = paint.fDstBlendCoeff;
+fAntiAlias = paint.fAntiAlias;
+fDither = paint.fDither;
+fColor = paint.fColor;
+fCoverage = paint.fCoverage;
+fColorStages = paint.fColorStages;
+fCoverageStages = paint.fCoverageStages;
+return *this;
+}
+/**
+* Resets the paint to the defaults.
+*/
+void reset() {
+this->resetBlend();
+this->resetOptions();
+this->resetColor();
+this->resetCoverage();
+this->resetStages();
+}
+/**
+* Determines whether the drawing with this paint is opaque with respect to both color blending
+* and fractional coverage. It does not consider whether AA has been enabled on the paint or
+* not. Depending upon whether multisampling or coverage-based AA is in use, AA may make the
+* result only apply to the interior of primitives.
+*
+*/
+bool isOpaque() const;
+/**
+* Returns true if isOpaque would return true and the paint represents a solid constant color
+* draw. If the result is true, constantColor will be updated to contain the constant color.
+*/
+bool isOpaqueAndConstantColor(GrColor* constantColor) const;
+private:
+/**
+* Helper for isOpaque and isOpaqueAndConstantColor.
+*/
+bool getOpaqueAndKnownColor(GrColor* solidColor, uint32_t* solidColorKnownComponents) const;
+/**
+* Called when the source coord system from which geometry is rendered changes. It ensures that
+* the local coordinates seen by effects remains unchanged. oldToNew gives the transformation
+* from the previous coord system to the new coord system.
+*/
+void localCoordChange(const SkMatrix& oldToNew) {
+for (int i = 0; i < fColorStages.count(); ++i) {
+fColorStages[i].localCoordChange(oldToNew);
+}
+for (int i = 0; i < fCoverageStages.count(); ++i) {
+fCoverageStages[i].localCoordChange(oldToNew);
+}
+}
+bool localCoordChangeInverse(const SkMatrix& newToOld) {
+SkMatrix oldToNew;
+bool computed = false;
+for (int i = 0; i < fColorStages.count(); ++i) {
+if (!computed && !newToOld.invert(&oldToNew)) {
+return false;
+} else {
+computed = true;
+}
+fColorStages[i].localCoordChange(oldToNew);
+}
+for (int i = 0; i < fCoverageStages.count(); ++i) {
+if (!computed && !newToOld.invert(&oldToNew)) {
+return false;
+} else {
+computed = true;
+}
+fCoverageStages[i].localCoordChange(oldToNew);
+}
+return true;
+}
+friend class GrContext; // To access above two functions
+SkSTArray<4, GrEffectStage> fColorStages;
+SkSTArray<2, GrEffectStage> fCoverageStages;
+GrBlendCoeff                fSrcBlendCoeff;
+GrBlendCoeff                fDstBlendCoeff;
+bool                        fAntiAlias;
+bool                        fDither;
+GrColor                     fColor;
+uint8_t                     fCoverage;
+void resetBlend() {
+fSrcBlendCoeff = kOne_GrBlendCoeff;
+fDstBlendCoeff = kZero_GrBlendCoeff;
+}
+void resetOptions() {
+fAntiAlias = false;
+fDither = false;
+}
+void resetColor() {
+fColor = GrColorPackRGBA(0xff, 0xff, 0xff, 0xff);
+}
+void resetCoverage() {
+fCoverage = 0xff;
+}
+void resetStages() {
+fColorStages.reset();
+fCoverageStages.reset();
+}
+};
+#endif

The Tor Browser / file comparison

comparison: gfx/skia/trunk/include/gpu/GrPaint.h

gfx/skia/trunk/include/gpu/GrPaint.h