1 files changed, 224 insertions, 0 deletions
diff --git a/Source/WebCore/platform/graphics/ImageBackingStore.h b/Source/WebCore/platform/graphics/ImageBackingStore.h
new file mode 100644
index 000000000..4c59f6842
--- /dev/null
+++ b/Source/WebCore/platform/graphics/ImageBackingStore.h
@@ -0,0 +1,224 @@
+/*
+ * Copyright (C) 2016 Apple Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "Color.h"
+#include "IntRect.h"
+#include "IntSize.h"
+#include "NativeImage.h"
+#include "SharedBuffer.h"
+
+namespace WebCore {
+
+class ImageBackingStore {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    static std::unique_ptr<ImageBackingStore> create(const IntSize& size, bool premultiplyAlpha = true)
+    {
+        return std::unique_ptr<ImageBackingStore>(new ImageBackingStore(size, premultiplyAlpha));
+    }
+
+    static std::unique_ptr<ImageBackingStore> create(const ImageBackingStore& other)
+    {
+        return std::unique_ptr<ImageBackingStore>(new ImageBackingStore(other));
+    }
+
+    NativeImagePtr image() const;
+
+    bool setSize(const IntSize& size)
+    {
+        if (size.isEmpty())
+            return false;
+
+        Vector<char> buffer;
+        size_t bufferSize = size.area().unsafeGet() * sizeof(RGBA32);
+
+        if (!buffer.tryReserveCapacity(bufferSize))
+            return false;
+
+        buffer.resize(bufferSize);
+        m_pixels = SharedBuffer::adoptVector(buffer);
+        m_pixelsPtr = reinterpret_cast<RGBA32*>(const_cast<char*>(m_pixels->data()));
+        m_size = size;
+        m_frameRect = IntRect(IntPoint(), m_size);
+        clear();
+        return true;
+    }
+
+    void setFrameRect(const IntRect& frameRect)
+    {
+        ASSERT(!m_size.isEmpty());
+        ASSERT(inBounds(frameRect));
+        m_frameRect = frameRect;
+    }
+
+    const IntSize& size() const { return m_size; }
+    const IntRect& frameRect() const { return m_frameRect; }
+
+    void clear()
+    {
+        memset(m_pixelsPtr, 0, (m_size.area() * sizeof(RGBA32)).unsafeGet());
+    }
+
+    void clearRect(const IntRect& rect)
+    {
+        if (rect.isEmpty() || !inBounds(rect))
+            return;
+
+        size_t rowBytes = rect.width() * sizeof(RGBA32);
+        RGBA32* start = pixelAt(rect.x(), rect.y());
+        for (int i = 0; i < rect.height(); ++i) {
+            memset(start, 0, rowBytes);
+            start += m_size.width();
+        }
+    }
+
+    void fillRect(const IntRect &rect, unsigned r, unsigned g, unsigned b, unsigned a)
+    {
+        if (rect.isEmpty() || !inBounds(rect))
+            return;
+
+        RGBA32* start = pixelAt(rect.x(), rect.y());
+        RGBA32 pixelValue = this->pixelValue(r, g, b, a);
+        for (int i = 0; i < rect.height(); ++i) {
+            for (int j = 0; j < rect.width(); ++j)
+                start[j] = pixelValue;
+            start += m_size.width();
+        }
+    }
+
+    void repeatFirstRow(const IntRect& rect)
+    {
+        if (rect.isEmpty() || !inBounds(rect))
+            return;
+
+        size_t rowBytes = rect.width() * sizeof(RGBA32);
+        RGBA32* src = pixelAt(rect.x(), rect.y());
+        RGBA32* dest = src + m_size.width();
+        for (int i = 1; i < rect.height(); ++i) {
+            memcpy(dest, src, rowBytes);
+            dest += m_size.width();
+        }
+    }
+
+    RGBA32* pixelAt(int x, int y) const
+    {
+        ASSERT(inBounds(IntPoint(x, y)));
+        return m_pixelsPtr + y * m_size.width() + x;
+    }
+
+    void setPixel(RGBA32* dest, unsigned r, unsigned g, unsigned b, unsigned a)
+    {
+        ASSERT(dest);
+        *dest = pixelValue(r, g, b, a);
+    }
+
+    void setPixel(int x, int y, unsigned r, unsigned g, unsigned b, unsigned a)
+    {
+        setPixel(pixelAt(x, y), r, g, b, a);
+    }
+
+#if ENABLE(APNG)
+    void blendPixel(RGBA32* dest, unsigned r, unsigned g, unsigned b, unsigned a)
+    {
+        if (!a)
+            return;
+
+        if (a >= 255 || !alphaChannel(*dest)) {
+            setPixel(dest, r, g, b, a);
+            return;
+        }
+
+        if (!m_premultiplyAlpha)
+            *dest = makePremultipliedRGBA(redChannel(*dest), greenChannel(*dest), blueChannel(*dest), alphaChannel(*dest), false);
+
+        unsigned d = 255 - a;
+
+        r = fastDivideBy255(r * a + redChannel(*dest) * d);
+        g = fastDivideBy255(g * a + greenChannel(*dest) * d);
+        b = fastDivideBy255(b * a + blueChannel(*dest) * d);
+        a += fastDivideBy255(d * alphaChannel(*dest));
+
+        if (m_premultiplyAlpha)
+            *dest = makeRGBA(r, g, b, a);
+        else
+            *dest = makeUnPremultipliedRGBA(r, g, b, a);
+    }
+#endif
+
+    static bool isOverSize(const IntSize& size)
+    {
+        static unsigned long long MaxPixels = ((1 << 29) - 1);
+        unsigned long long pixels = static_cast<unsigned long long>(size.width()) * static_cast<unsigned long long>(size.height());
+        return pixels > MaxPixels;
+    }
+
+private:
+    ImageBackingStore(const IntSize& size, bool premultiplyAlpha = true)
+        : m_premultiplyAlpha(premultiplyAlpha)
+    {
+        ASSERT(!size.isEmpty() && !isOverSize(size));
+        setSize(size);
+    }
+
+    ImageBackingStore(const ImageBackingStore& other)
+        : m_size(other.m_size)
+        , m_premultiplyAlpha(other.m_premultiplyAlpha)
+    {
+        ASSERT(!m_size.isEmpty() && !isOverSize(m_size));
+        m_pixels = other.m_pixels->copy();
+        m_pixelsPtr = reinterpret_cast<RGBA32*>(const_cast<char*>(m_pixels->data()));
+    }
+
+    bool inBounds(const IntPoint& point) const
+    {
+        return IntRect(IntPoint(), m_size).contains(point);
+    }
+
+    bool inBounds(const IntRect& rect) const
+    {
+        return IntRect(IntPoint(), m_size).contains(rect);
+    }
+
+    RGBA32 pixelValue(unsigned r, unsigned g, unsigned b, unsigned a) const
+    {
+        if (m_premultiplyAlpha && !a)
+            return 0;
+
+        if (m_premultiplyAlpha && a < 255)
+            return makePremultipliedRGBA(r, g, b, a, false);
+
+        return makeRGBA(r, g, b, a);
+    }
+
+    RefPtr<SharedBuffer> m_pixels;
+    RGBA32* m_pixelsPtr { nullptr };
+    IntSize m_size;
+    IntRect m_frameRect; // This will always just be the entire buffer except for GIF and PNG frames
+    bool m_premultiplyAlpha { true };
+};
+
+}