Add skia to the repository.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@16 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 120 insertions, 0 deletions

diff --git a/skia/images/SkCreateRLEPixelRef.cpp b/skia/images/SkCreateRLEPixelRef.cpp
new file mode 100644
index 0000000..5756237
--- /dev/null
+++ b/skia/images/SkCreateRLEPixelRef.cpp
@@ -0,0 +1,120 @@
+#include "SkChunkAlloc.h"
+#include "SkPackBits.h"
+#include "SkBitmap.h"
+#include "SkPixelRef.h"
+
+class RLEPixelRef : public SkPixelRef {
+public:
+    RLEPixelRef(SkBitmap::RLEPixels* rlep, SkColorTable* ctable);
+    virtual ~RLEPixelRef();
+    
+protected:
+    // overrides from SkPixelRef
+    virtual void* onLockPixels(SkColorTable**);
+    virtual void onUnlockPixels();
+    
+private:
+    SkBitmap::RLEPixels* fRLEPixels;
+    SkColorTable*        fCTable;
+};
+
+RLEPixelRef::RLEPixelRef(SkBitmap::RLEPixels* rlep, SkColorTable* ctable)
+        : SkPixelRef(NULL) {
+    fRLEPixels = rlep;  // we now own this ptr
+    fCTable = ctable;
+    ctable->safeRef();
+}
+
+RLEPixelRef::~RLEPixelRef() {
+    SkDELETE(fRLEPixels);
+    fCTable->safeUnref();
+}
+
+void* RLEPixelRef::onLockPixels(SkColorTable** ct) {
+    *ct = fCTable;
+    return fRLEPixels;
+}
+
+void RLEPixelRef::onUnlockPixels() {
+    // nothing to do
+}
+
+/////////////////////////////////////////////////////////////////////////////
+
+class ChunkRLEPixels : public SkBitmap::RLEPixels {
+public:
+    ChunkRLEPixels(int width, int height, size_t chunkSize)
+        : SkBitmap::RLEPixels(width, height), fStorage(chunkSize) {
+    }
+    
+    SkChunkAlloc fStorage;
+};
+
+SkPixelRef* SkCreateRLEPixelRef(const SkBitmap& src);
+SkPixelRef* SkCreateRLEPixelRef(const SkBitmap& src) {
+    
+    if (SkBitmap::kIndex8_Config != src.config() &&
+            SkBitmap::kA8_Config != src.config()) {
+        return NULL;
+    }
+    
+    size_t maxPacked = SkPackBits::ComputeMaxSize8(src.width());
+
+    // estimate the rle size based on the original size
+    size_t size = src.getSize() >> 3;
+    if (size < maxPacked) {
+        size = maxPacked;
+    }
+
+    ChunkRLEPixels* rlePixels = SkNEW_ARGS(ChunkRLEPixels,
+                                           (src.width(), src.height(), size));
+
+    uint8_t* dstRow = NULL;
+    size_t free = 0;
+    size_t totalPacked = 0;
+
+    for (int y = 0; y < src.height(); y++) {
+        const uint8_t* srcRow = src.getAddr8(0, y);
+        
+        if (free < maxPacked) {
+            dstRow = (uint8_t*)rlePixels->fStorage.allocThrow(size);
+            free = size;
+        }
+        size_t packedSize = SkPackBits::Pack8(srcRow, src.width(), dstRow);
+        SkASSERT(packedSize <= free);
+        rlePixels->setPackedAtY(y, dstRow);
+        
+        dstRow += packedSize;
+        free -= packedSize;
+        
+        totalPacked += packedSize;
+    }
+    
+//#ifdef SK_DEBUG
+#if 0
+    // test
+    uint8_t* buffer = new uint8_t[src.width()];
+    for (int y = 0; y < src.height(); y++) {
+        const uint8_t* srcRow = src.getAddr8(0, y);
+        SkPackBits::Unpack8(buffer, 0, src.width(), rlePixels->packedAtY(y));
+        int n = memcmp(buffer, srcRow, src.width());
+        if (n) {
+            SkDebugf("----- memcmp returned %d on line %d\n", n, y);
+        }
+        SkASSERT(n == 0);
+    }
+    delete[] buffer;
+
+    size_t totalAlloc = src.height() * sizeof(uint8_t*) + totalPacked;
+    
+    SkDebugf("--- RLE: orig [%d %d] %d, rle %d %d savings %g\n",
+             src.width(), src.height(), src.getSize(),
+             src.height() * sizeof(uint8_t*), totalPacked,
+             (float)totalAlloc / src.getSize());
+
+#endif
+
+    // transfer ownership of rlePixels to our pixelref
+    return SkNEW_ARGS(RLEPixelRef, (rlePixels, src.getColorTable()));
+}
+