diff options
Diffstat (limited to 'include/core/SkShader.h')
| -rw-r--r-- | include/core/SkShader.h | 52 |
1 files changed, 48 insertions, 4 deletions
diff --git a/include/core/SkShader.h b/include/core/SkShader.h index f3d4856..1cdbf17 100644 --- a/include/core/SkShader.h +++ b/include/core/SkShader.h @@ -145,12 +145,56 @@ public: virtual void beginSession(); virtual void endSession(); + /** + Gives method bitmap should be read to implement a shader. + Also determines number and interpretation of "extra" parameters returned + by asABitmap + */ + enum BitmapType { + kNone_BitmapType, //<! Shader is not represented as a bitmap + kDefault_BitmapType,//<! Access bitmap using local coords transformed + // by matrix. No extras + kRadial_BitmapType, //<! Access bitmap by transforming local coordinates + // by the matrix and taking the distance of result + // from (0,0) as bitmap column. Bitmap is 1 pixel + // tall. No extras + kSweep_BitmapType, //<! Access bitmap by transforming local coordinates + // by the matrix and taking the angle of result + // to (0,0) as bitmap x coord, where angle = 0 is + // bitmap left edge of bitmap = 2pi is the + // right edge. Bitmap is 1 pixel tall. No extras + kTwoPointRadial_BitmapType + //<! Matrix transforms to space where (0,0) is + // the center of the starting circle. The second + // circle will be centered (x, 0) where x may be + // 0. The post-matrix space is normalized such + // that 1 is the second radius - first radius. + // Three extra parameters are returned: + // 0: x-offset of second circle center + // to first. + // 1: radius of first circle in post-matrix + // space + // 2: the second radius minus the first radius + // in pre-transformed space. + + }; /** Optional methods for shaders that can pretend to be a bitmap/texture - to play along with opengl. Default just returns false and ignores - the out parameters. + to play along with opengl. Default just returns kNone_BitmapType and + ignores the out parameters. + + @param outTexture if non-NULL will be the bitmap representing the shader + after return. + @param outMatrix if non-NULL will be the matrix to apply to vertices + to access the bitmap after return. + @param xy if non-NULL will be the tile modes that should be + used to access the bitmap after return. + @param twoPointRadialParams Two extra return values needed for two point + radial bitmaps. The first is the x-offset of + the second point and the second is the radius + about the first point. */ - virtual bool asABitmap(SkBitmap* outTexture, SkMatrix* outMatrix, - TileMode xy[2]); + virtual BitmapType asABitmap(SkBitmap* outTexture, SkMatrix* outMatrix, + TileMode xy[2], SkScalar* twoPointRadialParams); ////////////////////////////////////////////////////////////////////////// // Factory methods for stock shaders |