Add skia to the repository.

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

1 files changed, 240 insertions, 0 deletions

diff --git a/skia/effects/SkNinePatch.cpp b/skia/effects/SkNinePatch.cpp
new file mode 100644
index 0000000..267c39e
--- /dev/null
+++ b/skia/effects/SkNinePatch.cpp
@@ -0,0 +1,240 @@
+/*
+** Copyright 2006, Google Inc.
+**
+** 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 "SkNinePatch.h"
+#include "SkCanvas.h"
+#include "SkShader.h"
+
+static const uint16_t g3x3Indices[] = {
+    0, 5, 1,    0, 4, 5,
+    1, 6, 2,    1, 5, 6,
+    2, 7, 3,    2, 6, 7,
+    
+    4, 9, 5,    4, 8, 9,
+    5, 10, 6,   5, 9, 10,
+    6, 11, 7,   6, 10, 11,
+    
+    8, 13, 9,   8, 12, 13,
+    9, 14, 10,  9, 13, 14,
+    10, 15, 11, 10, 14, 15
+};
+
+static int fillIndices(uint16_t indices[], int xCount, int yCount) {
+    uint16_t* startIndices = indices;
+    
+    int n = 0;
+    for (int y = 0; y < yCount; y++) {
+        for (int x = 0; x < xCount; x++) {
+            *indices++ = n;
+            *indices++ = n + xCount + 2;
+            *indices++ = n + 1;
+            
+            *indices++ = n;
+            *indices++ = n + xCount + 1;
+            *indices++ = n + xCount + 2;
+            
+            n += 1;
+        }
+        n += 1;
+    }
+    return indices - startIndices;
+}
+
+static void fillRow(SkPoint verts[], SkPoint texs[],
+                    const SkScalar vy, const SkScalar ty,
+                    const SkRect& bounds, const int32_t xDivs[], int numXDivs,
+                    const SkScalar stretchX, int width) {
+    SkScalar vx = bounds.fLeft;
+    verts->set(vx, vy); verts++;
+    texs->set(0, ty); texs++;
+    for (int x = 0; x < numXDivs; x++) {
+        SkScalar tx = SkIntToScalar(xDivs[x]);
+        if (x & 1) {
+            vx += stretchX;
+        } else {
+            vx += tx;
+        }
+        verts->set(vx, vy); verts++;
+        texs->set(tx, ty); texs++;
+    }
+    verts->set(bounds.fRight, vy); verts++;
+    texs->set(SkIntToScalar(width), ty); texs++;
+}
+
+struct Mesh {
+    const SkPoint*  fVerts;
+    const SkPoint*  fTexs;
+    const SkColor*  fColors;
+    const uint16_t* fIndices;
+};
+
+void SkNinePatch::DrawMesh(SkCanvas* canvas, const SkRect& bounds,
+                           const SkBitmap& bitmap,
+                           const int32_t xDivs[], int numXDivs,
+                           const int32_t yDivs[], int numYDivs,
+                           const SkPaint* paint) {
+    if (bounds.isEmpty() || bitmap.width() == 0 || bitmap.height() == 0) {
+        return;
+    }
+    
+    // should try a quick-reject test before calling lockPixels <reed>
+    SkAutoLockPixels alp(bitmap);
+    // after the lock, it is valid to check getPixels()
+    if (bitmap.getPixels() == NULL) {
+        return;
+    }
+    
+    // check for degenerate divs (just an optimization, not required)
+    {
+        int i;
+        int zeros = 0;
+        for (i = 0; i < numYDivs && yDivs[i] == 0; i++) {
+            zeros += 1;
+        }
+        numYDivs -= zeros;
+        yDivs += zeros;
+        for (i = numYDivs - 1; i >= 0 && yDivs[i] == bitmap.height(); --i) {
+            numYDivs -= 1;
+        }
+    }
+    
+    Mesh mesh;
+    
+    const int numXStretch = (numXDivs + 1) >> 1;
+    const int numYStretch = (numYDivs + 1) >> 1;
+    
+    if (numXStretch < 1 && numYStretch < 1) {
+    BITMAP_RECT:
+//        SkDebugf("------ drawasamesh revert to bitmaprect\n");
+        canvas->drawBitmapRect(bitmap, NULL, bounds, paint);
+        return;
+    }
+    
+    if (false) {
+        int i;
+        for (i = 0; i < numXDivs; i++) {
+            SkDebugf("--- xdivs[%d] %d\n", i, xDivs[i]);
+        }
+        for (i = 0; i < numYDivs; i++) {
+            SkDebugf("--- ydivs[%d] %d\n", i, yDivs[i]);
+        }
+    }
+    
+    SkScalar stretchX = 0, stretchY = 0;
+    
+    if (numXStretch > 0) {
+        int stretchSize = 0;
+        for (int i = 1; i < numXDivs; i += 2) {
+            stretchSize += xDivs[i] - xDivs[i-1];
+        }
+        int fixed = bitmap.width() - stretchSize;
+        stretchX = (bounds.width() - SkIntToScalar(fixed)) / numXStretch;
+        if (stretchX < 0) {
+            goto BITMAP_RECT;
+        }
+    }
+    
+    if (numYStretch > 0) {
+        int stretchSize = 0;
+        for (int i = 1; i < numYDivs; i += 2) {
+            stretchSize += yDivs[i] - yDivs[i-1];
+        }
+        int fixed = bitmap.height() - stretchSize;
+        stretchY = (bounds.height() - SkIntToScalar(fixed)) / numYStretch;
+        if (stretchY < 0) {
+            goto BITMAP_RECT;
+        }
+    }
+    
+#if 0
+    SkDebugf("---- drawasamesh [%d %d] -> [%g %g] <%d %d> (%g %g)\n",
+             bitmap.width(), bitmap.height(),
+             SkScalarToFloat(bounds.width()), SkScalarToFloat(bounds.height()),
+             numXDivs + 1, numYDivs + 1,
+             SkScalarToFloat(stretchX), SkScalarToFloat(stretchY));
+#endif
+
+    const int vCount = (numXDivs + 2) * (numYDivs + 2);
+    // number of celss * 2 (tris per cell) * 3 (verts per tri)
+    const int indexCount = (numXDivs + 1) * (numYDivs + 1) * 2 * 3;
+    // allocate 2 times, one for verts, one for texs, plus indices
+    SkAutoMalloc storage(vCount * sizeof(SkPoint) * 2 +
+                         indexCount * sizeof(uint16_t));
+    SkPoint* verts = (SkPoint*)storage.get();
+    SkPoint* texs = verts + vCount;
+    uint16_t* indices = (uint16_t*)(texs + vCount);
+    
+    mesh.fVerts = verts;
+    mesh.fTexs = texs;
+    mesh.fColors = NULL;
+    mesh.fIndices = NULL;
+    
+    // we use <= for YDivs, since the prebuild indices work for 3x2 and 3x1 too
+    if (numXDivs == 2 && numYDivs <= 2) {
+        mesh.fIndices = g3x3Indices;
+    } else {
+        int n = fillIndices(indices, numXDivs + 1, numYDivs + 1);
+        SkASSERT(n == indexCount);
+        mesh.fIndices = indices;
+    }
+    
+    SkScalar vy = bounds.fTop;
+    fillRow(verts, texs, vy, 0, bounds, xDivs, numXDivs,
+            stretchX, bitmap.width());
+    verts += numXDivs + 2;
+    texs += numXDivs + 2;
+    for (int y = 0; y < numYDivs; y++) {
+        const SkScalar ty = SkIntToScalar(yDivs[y]);
+        if (y & 1) {
+            vy += stretchY;
+        } else {
+            vy += ty;
+        }
+        fillRow(verts, texs, vy, ty, bounds, xDivs, numXDivs,
+                stretchX, bitmap.width());
+        verts += numXDivs + 2;
+        texs += numXDivs + 2;
+    }
+    fillRow(verts, texs, bounds.fBottom, SkIntToScalar(bitmap.height()),
+            bounds, xDivs, numXDivs, stretchX, bitmap.width());
+    
+    SkShader* shader = SkShader::CreateBitmapShader(bitmap,
+                                                    SkShader::kClamp_TileMode,
+                                                    SkShader::kClamp_TileMode);
+    SkPaint p;
+    if (paint) {
+        p = *paint;
+    }
+    p.setShader(shader)->unref();
+    canvas->drawVertices(SkCanvas::kTriangles_VertexMode, vCount,
+                         mesh.fVerts, mesh.fTexs, mesh.fColors, NULL,
+                         mesh.fIndices, indexCount, p);
+}
+
+void SkNinePatch::DrawNine(SkCanvas* canvas, const SkRect& bounds,
+                           const SkBitmap& bitmap, const SkIRect& margins,
+                           const SkPaint* paint) {
+    int32_t xDivs[2];
+    int32_t yDivs[2];
+    
+    xDivs[0] = margins.fLeft;
+    xDivs[1] = bitmap.width() - margins.fRight;
+    yDivs[0] = margins.fTop;
+    yDivs[1] = bitmap.height() - margins.fBottom;
+
+    SkNinePatch::DrawMesh(canvas, bounds, bitmap, xDivs, 2, yDivs, 2, paint);
+}
+