1 files changed, 51 insertions, 0 deletions
diff --git a/libs/graphics/effects/SkShaderExtras.cpp b/libs/graphics/effects/SkShaderExtras.cpp
new file mode 100644
index 0000000000..cf8f047de1
--- /dev/null
+++ b/libs/graphics/effects/SkShaderExtras.cpp
@@ -0,0 +1,51 @@
+#include "SkShader.h"
+#include "SkColorFilter.h"
+#include "SkShaderExtras.h"
+
+//////////////////////////////////////////////////////////////////////////////////////
+    
+SkComposeShader::SkComposeShader(SkShader* sA, SkShader* sB, SkColorCombine* combine)
+{
+    fShaderA = sA;      sA->ref();
+    fShaderB = sB;      sB->ref();
+    fCombine = combine; combine->ref();
+}
+
+SkComposeShader::~SkComposeShader()
+{
+    fCombine->unref();
+    fShaderB->unref();
+    fShaderA->unref();
+}
+
+bool SkComposeShader::setContext(const SkBitmap& device,
+                                 const SkPaint& paint,
+                                 const SkMatrix& matrix)
+{
+    return  this->INHERITED::setContext(device, paint, matrix) &&
+            fShaderA->setContext(device, paint, matrix) &&
+            fShaderA->setContext(device, paint, matrix);
+}
+
+void SkComposeShader::shadeSpan(int x, int y, SkPMColor result[], int count)
+{
+    SkShader*       shaderA = fShaderA;
+    SkShader*       shaderB = fShaderB;
+    SkColorCombine* combine = fCombine;
+    
+    SkPMColor       tmp[COUNT];
+    do {
+        int n = count;
+        if (n > COUNT)
+            n = COUNT;
+        
+        shaderA->shadeSpan(x, y, tmp, n);
+        shaderB->shadeSpan(x, y, result, n);
+        combine->combineSpan(tmp, result, n, result);
+        
+        result += n;
+        x += n;
+        count -= n;
+    } while (count > 0);
+}
+