Implement SkColorFilter::asColorMatrix() virtual, and override in

SkColorMatrixFilter.  Implement missing SkColorMatrixFilter::setMatrix() and
setArray() functions (were in .h, just not implemented).  Add a gm for color
matrix filters.

Review URL:  http://codereview.appspot.com/5500044/



git-svn-id: http://skia.googlecode.com/svn/trunk@2909 2bbb7eff-a529-9590-31e7-b0007b416f81

2 files changed, 28 insertions, 0 deletions

diff --git a/src/core/SkColorFilter.cpp b/src/core/SkColorFilter.cpp
index d3f5faa955..e91488b18c 100644
--- a/src/core/SkColorFilter.cpp
+++ b/src/core/SkColorFilter.cpp
@@ -15,6 +15,10 @@ bool SkColorFilter::asColorMode(SkColor* color, SkXfermode::Mode* mode) {
     return false;
 }
 
+bool SkColorFilter::asColorMatrix(SkScalar matrix[20]) {
+    return false;
+}
+
 void SkColorFilter::filterSpan16(const uint16_t s[], int count, uint16_t d[]) {
     SkASSERT(this->getFlags() & SkColorFilter::kHasFilter16_Flag);
     SkASSERT(!"missing implementation of SkColorFilter::filterSpan16");
diff --git a/src/effects/SkColorMatrixFilter.cpp b/src/effects/SkColorMatrixFilter.cpp
index a58e06da78..5ed86981a2 100644
--- a/src/effects/SkColorMatrixFilter.cpp
+++ b/src/effects/SkColorMatrixFilter.cpp
@@ -333,8 +333,32 @@ SkColorMatrixFilter::SkColorMatrixFilter(SkFlattenableReadBuffer& buffer)
     fFlags = buffer.readU32();
 }
 
+bool SkColorMatrixFilter::asColorMatrix(SkScalar matrix[20]) {
+    int32_t* SK_RESTRICT array = fState.fArray;
+    for (int i = 0; i < 20; i++) {
+        matrix[i] = SkFixedToScalar(array[i]);
+    }
+    if (NULL != fProc) {
+        // Undo the offset applied to the constant column in setup().
+        SkScalar offset = SkFixedToScalar(1 << (fState.fShift - 1));
+        matrix[4] -= offset;
+        matrix[9] -= offset;
+        matrix[14] -= offset;
+        matrix[19] -= offset;
+    }
+    return true;
+}
+
 SkFlattenable* SkColorMatrixFilter::CreateProc(SkFlattenableReadBuffer& buf) {
     return SkNEW_ARGS(SkColorMatrixFilter, (buf));
 }
 
+void SkColorMatrixFilter::setMatrix(const SkColorMatrix& matrix) {
+    setup(matrix.fMat);
+}
+
+void SkColorMatrixFilter::setArray(const SkScalar array[20]) {
+    setup(array);
+}
+
 SK_DEFINE_FLATTENABLE_REGISTRAR(SkColorMatrixFilter)