grab from latest android

git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 144 insertions, 0 deletions

diff --git a/src/effects/SkTransparentShader.cpp b/src/effects/SkTransparentShader.cpp
new file mode 100644
index 0000000000..6b79839fe6
--- /dev/null
+++ b/src/effects/SkTransparentShader.cpp
@@ -0,0 +1,144 @@
+/* libs/graphics/effects/SkTransparentShader.cpp
+**
+** Copyright 2006, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License"); 
+** you may not use this file except in compliance with the License. 
+** You may obtain a copy of the License at 
+**
+**     http://www.apache.org/licenses/LICENSE-2.0 
+**
+** Unless required by applicable law or agreed to in writing, software 
+** distributed under the License is distributed on an "AS IS" BASIS, 
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
+** See the License for the specific language governing permissions and 
+** limitations under the License.
+*/
+
+#include "SkTransparentShader.h"
+#include "SkColorPriv.h"
+
+bool SkTransparentShader::setContext(const SkBitmap& device,
+                                     const SkPaint& paint,
+                                     const SkMatrix& matrix)
+{
+    fDevice = &device;
+    fAlpha = paint.getAlpha();
+
+    return this->INHERITED::setContext(device, paint, matrix);
+}
+
+uint32_t SkTransparentShader::getFlags()
+{
+    uint32_t flags = this->INHERITED::getFlags();
+
+    switch (fDevice->getConfig()) {
+    case SkBitmap::kRGB_565_Config:
+        flags |= kHasSpan16_Flag;
+        if (fAlpha == 255)
+            flags |= kOpaqueAlpha_Flag;
+        break;
+    case SkBitmap::kARGB_8888_Config:
+    case SkBitmap::kARGB_4444_Config:
+        if (fAlpha == 255 && fDevice->isOpaque())
+            flags |= kOpaqueAlpha_Flag;
+        break;
+    default:
+        break;
+    }
+    return flags;
+}
+
+void SkTransparentShader::shadeSpan(int x, int y, SkPMColor span[], int count)
+{
+    unsigned scale = SkAlpha255To256(fAlpha);
+
+    switch (fDevice->getConfig()) {
+    case SkBitmap::kARGB_8888_Config:
+        if (scale == 256)
+            memcpy(span, fDevice->getAddr32(x, y), count * sizeof(SkPMColor));
+        else
+        {
+            const SkPMColor* src = fDevice->getAddr32(x, y);
+            for (int i = count - 1; i >= 0; --i)
+                span[i] = SkAlphaMulQ(src[i], scale);
+        }
+        break;
+    case SkBitmap::kRGB_565_Config:
+        {
+            const uint16_t* src = fDevice->getAddr16(x, y);
+            if (scale == 256)
+            {
+                for (int i = count - 1; i >= 0; --i)
+                    span[i] = SkPixel16ToPixel32(src[i]);
+            }
+            else
+            {
+                unsigned alpha = fAlpha;
+                for (int i = count - 1; i >= 0; --i)
+                {
+                    uint16_t c = src[i];
+                    unsigned r = SkPacked16ToR32(c);
+                    unsigned g = SkPacked16ToG32(c);
+                    unsigned b = SkPacked16ToB32(c);
+
+                    span[i] = SkPackARGB32( alpha,
+                                            SkAlphaMul(r, scale),
+                                            SkAlphaMul(g, scale),
+                                            SkAlphaMul(b, scale));
+                }
+            }
+        }
+        break;
+    case SkBitmap::kARGB_4444_Config:
+        {
+            const uint16_t* src = fDevice->getAddr16(x, y);
+            if (scale == 256)
+            {
+                for (int i = count - 1; i >= 0; --i)
+                    span[i] = SkPixel4444ToPixel32(src[i]);
+            }
+            else
+            {
+                unsigned scale16 = scale >> 4;
+                for (int i = count - 1; i >= 0; --i)
+                {
+                    uint32_t c = SkExpand_4444(src[i]) * scale16;
+                    span[i] = SkCompact_8888(c);
+                }
+            }
+        }
+            break;
+            case SkBitmap::kIndex8_Config:
+        SkASSERT(!"index8 not supported as a destination device");
+        break;
+    case SkBitmap::kA8_Config:
+        {
+            const uint8_t* src = fDevice->getAddr8(x, y);
+            if (scale == 256)
+            {
+                for (int i = count - 1; i >= 0; --i)
+                    span[i] = SkPackARGB32(src[i], 0, 0, 0);
+            }
+            else
+            {
+                for (int i = count - 1; i >= 0; --i)
+                    span[i] = SkPackARGB32(SkAlphaMul(src[i], scale), 0, 0, 0);
+            }
+        }
+        break;
+    case SkBitmap::kA1_Config:
+        SkASSERT(!"kA1_Config umimplemented at this time");
+        break;
+    default:    // to avoid warnings
+        break;
+    }
+}
+
+void SkTransparentShader::shadeSpan16(int x, int y, uint16_t span[], int count)
+{
+    SkASSERT(fDevice->getConfig() == SkBitmap::kRGB_565_Config);
+
+    memcpy(span, fDevice->getAddr16(x, y), count << 1);
+}
+