Revert of Revert of Extract most of the mutable state of SkShader into a separate Context object. (https://codereview.chromium.org/249643002/)
Reason for revert:
Chromium side change landed along side DEPS roll that includes r14323.
Original issue's description:
> Revert of Extract most of the mutable state of SkShader into a separate Context object. (https://codereview.chromium.org/207683004/)
>
> Reason for revert:
> This is blocking the DEPS roll into Chromium. Failures can be seen here:
>
> http://build.chromium.org/p/tryserver.chromium/builders/android_dbg/builds/174333
>
> Original issue's description:
> > Extract most of the mutable state of SkShader into a separate Context object.
> >
> > SkShader currently stores some state during draw calls via setContext(...).
> > Move that mutable state into a separate SkShader::Context class that is
> > constructed on demand for the duration of the draw.
> >
> > Calls to setContext() are replaced with createContext() which returns a context
> > corresponding to the shader object or NULL if the parameters to createContext
> > are invalid.
> >
> > TEST=out/Debug/dm
> > BUG=skia:1976
> >
> > Committed: http://code.google.com/p/skia/source/detail?r=14216
> >
> > Committed: http://code.google.com/p/skia/source/detail?r=14323
>
> TBR=scroggo@google.com,skyostil@chromium.org,tomhudson@chromium.org,senorblanco@chromium.org,reed@google.com,bungeman@google.com,dominikg@chromium.org
> NOTREECHECKS=true
> NOTRY=true
> BUG=skia:1976
>
> Committed: http://code.google.com/p/skia/source/detail?r=14326
R=scroggo@google.com, skyostil@chromium.org, tomhudson@chromium.org, senorblanco@chromium.org, reed@google.com, bungeman@google.com, dominikg@chromium.org
TBR=bungeman@google.com, dominikg@chromium.org, reed@google.com, scroggo@google.com, senorblanco@chromium.org, skyostil@chromium.org, tomhudson@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=skia:1976
Author: bsalomon@google.com
Review URL: https://codereview.chromium.org/246403013
git-svn-id: http://skia.googlecode.com/svn/trunk@14328 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkShader.h b/include/core/SkShader.h
index 6566e69..cc2cc75 100644
--- a/include/core/SkShader.h
+++ b/include/core/SkShader.h
@@ -38,7 +38,7 @@
virtual ~SkShader();
/**
- * Returns true if the local matrix is not an identity matrix.
+ * Returns true if the local matrix is not an identity matrix.
*/
bool hasLocalMatrix() const { return !fLocalMatrix.isIdentity(); }
@@ -96,7 +96,7 @@
*/
kIntrinsicly16_Flag = 0x04,
- /** set (after setContext) if the spans only vary in X (const in Y).
+ /** set if the spans only vary in X (const in Y).
e.g. an Nx1 bitmap that is being tiled in Y, or a linear-gradient
that varies from left-to-right. This flag specifies this for
shadeSpan().
@@ -112,84 +112,111 @@
};
/**
- * Called sometimes before drawing with this shader. Return the type of
- * alpha your shader will return. The default implementation returns 0.
- * Your subclass should override if it can (even sometimes) report a
- * non-zero value, since that will enable various blitters to perform
- * faster.
- */
- virtual uint32_t getFlags() { return 0; }
-
- /**
* Returns true if the shader is guaranteed to produce only opaque
* colors, subject to the SkPaint using the shader to apply an opaque
* alpha value. Subclasses should override this to allow some
- * optimizations. isOpaque() can be called at any time, unlike getFlags,
- * which only works properly when the context is set.
+ * optimizations.
*/
virtual bool isOpaque() const { return false; }
- /**
- * Return the alpha associated with the data returned by shadeSpan16(). If
- * kHasSpan16_Flag is not set, this value is meaningless.
- */
- virtual uint8_t getSpan16Alpha() const { return fPaintAlpha; }
+ class Context : public ::SkNoncopyable {
+ public:
+ Context(const SkShader& shader, const SkBitmap& device,
+ const SkPaint& paint, const SkMatrix& matrix);
+
+ virtual ~Context();
+
+ /**
+ * Called sometimes before drawing with this shader. Return the type of
+ * alpha your shader will return. The default implementation returns 0.
+ * Your subclass should override if it can (even sometimes) report a
+ * non-zero value, since that will enable various blitters to perform
+ * faster.
+ */
+ virtual uint32_t getFlags() const { return 0; }
+
+ /**
+ * Return the alpha associated with the data returned by shadeSpan16(). If
+ * kHasSpan16_Flag is not set, this value is meaningless.
+ */
+ virtual uint8_t getSpan16Alpha() const { return fPaintAlpha; }
+
+ /**
+ * Called for each span of the object being drawn. Your subclass should
+ * set the appropriate colors (with premultiplied alpha) that correspond
+ * to the specified device coordinates.
+ */
+ virtual void shadeSpan(int x, int y, SkPMColor[], int count) = 0;
+
+ typedef void (*ShadeProc)(void* ctx, int x, int y, SkPMColor[], int count);
+ virtual ShadeProc asAShadeProc(void** ctx);
+
+ /**
+ * Called only for 16bit devices when getFlags() returns
+ * kOpaqueAlphaFlag | kHasSpan16_Flag
+ */
+ virtual void shadeSpan16(int x, int y, uint16_t[], int count);
+
+ /**
+ * Similar to shadeSpan, but only returns the alpha-channel for a span.
+ * The default implementation calls shadeSpan() and then extracts the alpha
+ * values from the returned colors.
+ */
+ virtual void shadeSpanAlpha(int x, int y, uint8_t alpha[], int count);
+
+ /**
+ * Helper function that returns true if this shader's shadeSpan16() method
+ * can be called.
+ */
+ bool canCallShadeSpan16() {
+ return SkShader::CanCallShadeSpan16(this->getFlags());
+ }
+
+ protected:
+ // Reference to shader, so we don't have to dupe information.
+ const SkShader& fShader;
+
+ enum MatrixClass {
+ kLinear_MatrixClass, // no perspective
+ kFixedStepInX_MatrixClass, // fast perspective, need to call fixedStepInX() each
+ // scanline
+ kPerspective_MatrixClass // slow perspective, need to mappoints each pixel
+ };
+ static MatrixClass ComputeMatrixClass(const SkMatrix&);
+
+ uint8_t getPaintAlpha() const { return fPaintAlpha; }
+ const SkMatrix& getTotalInverse() const { return fTotalInverse; }
+ MatrixClass getInverseClass() const { return (MatrixClass)fTotalInverseClass; }
+
+ private:
+ SkMatrix fTotalInverse;
+ uint8_t fPaintAlpha;
+ uint8_t fTotalInverseClass;
+
+ typedef SkNoncopyable INHERITED;
+ };
/**
- * Called once before drawing, with the current paint and device matrix.
- * Return true if your shader supports these parameters, or false if not.
- * If false is returned, nothing will be drawn. If true is returned, then
- * a balancing call to endContext() will be made before the next call to
- * setContext.
- *
- * Subclasses should be sure to call their INHERITED::setContext() if they
- * override this method.
+ * Subclasses should be sure to call their INHERITED::validContext() if
+ * they override this method.
*/
- virtual bool setContext(const SkBitmap& device, const SkPaint& paint,
- const SkMatrix& matrix);
+ virtual bool validContext(const SkBitmap& device, const SkPaint& paint,
+ const SkMatrix& matrix, SkMatrix* totalInverse = NULL) const;
/**
- * Assuming setContext returned true, endContext() will be called when
- * the draw using the shader has completed. It is an error for setContext
- * to be called twice w/o an intervening call to endContext().
- *
- * Subclasses should be sure to call their INHERITED::endContext() if they
- * override this method.
+ * Create the actual object that does the shading.
+ * Returns NULL if validContext() returns false.
+ * Size of storage must be >= contextSize.
*/
- virtual void endContext();
-
- SkDEBUGCODE(bool setContextHasBeenCalled() const { return SkToBool(fInSetContext); })
+ virtual Context* createContext(const SkBitmap& device,
+ const SkPaint& paint,
+ const SkMatrix& matrix,
+ void* storage) const = 0;
/**
- * Called for each span of the object being drawn. Your subclass should
- * set the appropriate colors (with premultiplied alpha) that correspond
- * to the specified device coordinates.
+ * Return the size of a Context returned by createContext.
*/
- virtual void shadeSpan(int x, int y, SkPMColor[], int count) = 0;
-
- typedef void (*ShadeProc)(void* ctx, int x, int y, SkPMColor[], int count);
- virtual ShadeProc asAShadeProc(void** ctx);
-
- /**
- * Called only for 16bit devices when getFlags() returns
- * kOpaqueAlphaFlag | kHasSpan16_Flag
- */
- virtual void shadeSpan16(int x, int y, uint16_t[], int count);
-
- /**
- * Similar to shadeSpan, but only returns the alpha-channel for a span.
- * The default implementation calls shadeSpan() and then extracts the alpha
- * values from the returned colors.
- */
- virtual void shadeSpanAlpha(int x, int y, uint8_t alpha[], int count);
-
- /**
- * Helper function that returns true if this shader's shadeSpan16() method
- * can be called.
- */
- bool canCallShadeSpan16() {
- return SkShader::CanCallShadeSpan16(this->getFlags());
- }
+ virtual size_t contextSize() const = 0;
/**
* Helper to check the flags to know if it is legal to call shadeSpan16()
@@ -322,7 +349,7 @@
* The incoming color to the effect has r=g=b=a all extracted from the SkPaint's alpha.
* The output color should be the computed SkShader premul color modulated by the incoming
* color. The GrContext may be used by the effect to create textures. The GPU device does not
- * call setContext. Instead we pass the SkPaint here in case the shader needs paint info.
+ * call createContext. Instead we pass the SkPaint here in case the shader needs paint info.
*/
virtual GrEffectRef* asNewEffect(GrContext* context, const SkPaint& paint) const;
@@ -362,26 +389,14 @@
SK_DEFINE_FLATTENABLE_TYPE(SkShader)
protected:
- enum MatrixClass {
- kLinear_MatrixClass, // no perspective
- kFixedStepInX_MatrixClass, // fast perspective, need to call fixedStepInX() each scanline
- kPerspective_MatrixClass // slow perspective, need to mappoints each pixel
- };
- static MatrixClass ComputeMatrixClass(const SkMatrix&);
-
- // These can be called by your subclass after setContext() has been called
- uint8_t getPaintAlpha() const { return fPaintAlpha; }
- const SkMatrix& getTotalInverse() const { return fTotalInverse; }
- MatrixClass getInverseClass() const { return (MatrixClass)fTotalInverseClass; }
SkShader(SkReadBuffer& );
virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
+
private:
SkMatrix fLocalMatrix;
- SkMatrix fTotalInverse;
- uint8_t fPaintAlpha;
- uint8_t fTotalInverseClass;
- SkDEBUGCODE(SkBool8 fInSetContext;)
+
+ bool computeTotalInverse(const SkMatrix& matrix, SkMatrix* totalInverse) const;
typedef SkFlattenable INHERITED;
};