1 files changed, 127 insertions, 0 deletions
diff --git a/libsgl/images/SkFlipPixelRef.cpp b/libsgl/images/SkFlipPixelRef.cpp
new file mode 100644
index 0000000..95403cc
--- /dev/null
+++ b/libsgl/images/SkFlipPixelRef.cpp
@@ -0,0 +1,127 @@
+#include "SkFlipPixelRef.h"
+#include "SkFlattenable.h"
+#include "SkRegion.h"
+
+SkFlipPixelRef::SkFlipPixelRef(SkBitmap::Config config, int width, int height)
+: fFlipper(width, height) {
+    fConfig = config;
+    fSize = SkBitmap::ComputeSize(config, width, height);
+    fStorage = sk_malloc_throw(fSize << 1);
+    fPage0 = fStorage;
+    fPage1 = (char*)fStorage + fSize;
+}
+
+SkFlipPixelRef::~SkFlipPixelRef() {
+    sk_free(fStorage);
+}
+
+const SkRegion& SkFlipPixelRef::beginUpdate(SkBitmap* device) {
+    void*       writeAddr;
+    const void* readAddr;
+    this->getFrontBack(&readAddr, &writeAddr);
+
+    device->setConfig(fConfig, fFlipper.width(), fFlipper.height());
+    device->setPixels(writeAddr);
+
+    SkRegion    copyBits;
+    const SkRegion& dirty = fFlipper.update(&copyBits);
+
+    SkFlipPixelRef::CopyBitsFromAddr(*device, copyBits, readAddr);
+    return dirty;
+}
+
+void SkFlipPixelRef::endUpdate() {
+    this->swapPages();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+void* SkFlipPixelRef::onLockPixels(SkColorTable** ct) {
+    fMutex.acquire();
+    *ct = NULL;
+    return fPage0;
+}
+
+void SkFlipPixelRef::onUnlockPixels() {
+    fMutex.release();
+}
+
+void SkFlipPixelRef::swapPages() {
+    fMutex.acquire();
+    SkTSwap<void*>(fPage0, fPage1);
+    fMutex.release();
+}
+
+void SkFlipPixelRef::flatten(SkFlattenableWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
+    
+    buffer.write32(fSize);
+    // only need to write page0
+    buffer.writePad(fPage0, fSize);
+}
+
+SkFlipPixelRef::SkFlipPixelRef(SkFlattenableReadBuffer& buffer)
+        : INHERITED(buffer, NULL) {
+    fSize = buffer.readU32();
+    fStorage = sk_malloc_throw(fSize << 1);
+    fPage0 = fStorage;
+    fPage1 = (char*)fStorage + fSize;
+    buffer.read(fPage0, fSize);
+}
+
+SkPixelRef* SkFlipPixelRef::Create(SkFlattenableReadBuffer& buffer) {
+    return SkNEW_ARGS(SkFlipPixelRef, (buffer));
+}
+
+static SkPixelRef::Registrar::Registrar reg("SkFlipPixelRef",
+                                            SkFlipPixelRef::Create);
+
+///////////////////////////////////////////////////////////////////////////////
+
+static void copyRect(const SkBitmap& dst, const SkIRect& rect,
+                     const void* srcAddr, int shift) {
+    const size_t offset = rect.fTop * dst.rowBytes() + (rect.fLeft << shift);
+    char* dstP = static_cast<char*>(dst.getPixels()) + offset;
+    const char* srcP = static_cast<const char*>(srcAddr) + offset;
+    const size_t rb = dst.rowBytes();
+    const size_t bytes = rect.width() << shift;
+    
+    int height = rect.height();
+    while (--height >= 0) {
+        memcpy(dstP, srcP, bytes);
+        dstP += rb;
+        srcP += rb;
+    }
+}
+
+static int getShift(SkBitmap::Config config) {
+    switch (config) {
+        case SkBitmap::kARGB_8888_Config:
+            return 2;
+        case SkBitmap::kRGB_565_Config:
+        case SkBitmap::kARGB_4444_Config:
+            return 1;
+        case SkBitmap::kIndex8_Config:
+        case SkBitmap::kA8_Config:
+            return 0;
+        default:
+            return -1;  // signal not supported
+    }
+}
+
+void SkFlipPixelRef::CopyBitsFromAddr(const SkBitmap& dst, const SkRegion& clip,
+                                      const void* srcAddr) {
+    const int shift = getShift(dst.config());
+    if (shift < 0) {
+        return;
+    }
+    
+    const SkIRect bounds = {0, 0, dst.width(), dst.height()};
+    SkRegion::Cliperator iter(clip, bounds);
+    
+    while (!iter.done()) {
+        copyRect(dst, iter.rect(), srcAddr, shift);
+        iter.next();
+    }
+}
+