Add SK_API to SkOverdrawCanvas and SkOverdrawColorFilter.

The SkiaRenderer in chromium is going to use the overdraw canvas and
filter for measuring overdraw. Move these headers out of src/ into
include/.

Bug: chromium:704285
Change-Id: I2abb1671b73e3d26552462cf700340a7e3b874f0
Reviewed-on: https://skia-review.googlesource.com/36160
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/include/effects/SkOverdrawColorFilter.h b/include/effects/SkOverdrawColorFilter.h
new file mode 100644
index 0000000000..ac97821269
--- /dev/null
+++ b/include/effects/SkOverdrawColorFilter.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkColorFilter.h"
+#include "SkFlattenable.h"
+
+#ifndef SkOverdrawColorFilter_DEFINED
+#define SkOverdrawColorFilter_DEFINED
+
+/**
+ *  Uses the value in the src alpha channel to set the dst pixel.
+ *  0             -> fColors[0]
+ *  1             -> fColors[1]
+ *  ...
+ *  5 (or larger) -> fColors[5]
+ *
+ */
+class SK_API SkOverdrawColorFilter : public SkColorFilter {
+public:
+    static constexpr int kNumColors = 6;
+
+    static sk_sp<SkOverdrawColorFilter> Make(const SkPMColor colors[kNumColors]) {
+        return sk_sp<SkOverdrawColorFilter>(new SkOverdrawColorFilter(colors));
+    }
+
+#if SK_SUPPORT_GPU
+    std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(GrContext*,
+                                                             SkColorSpace*) const override;
+#endif
+
+    void toString(SkString* str) const override;
+
+    static sk_sp<SkFlattenable> CreateProc(SkReadBuffer& buffer);
+    Factory getFactory() const override { return CreateProc; }
+    SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
+
+protected:
+    void flatten(SkWriteBuffer& buffer) const override;
+
+private:
+    SkOverdrawColorFilter(const SkPMColor colors[kNumColors]) {
+        memcpy(fColors, colors, kNumColors * sizeof(SkPMColor));
+    }
+
+    void onAppendStages(SkRasterPipeline*, SkColorSpace*, SkArenaAlloc*, bool) const override;
+
+    SkPMColor fColors[kNumColors];
+
+    typedef SkColorFilter INHERITED;
+};
+
+#endif // SkOverdrawColorFilter_DEFINED