update on boundary patches

git-svn-id: http://skia.googlecode.com/svn/trunk@409 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 96 insertions, 0 deletions

diff --git a/src/utils/SkMeshUtils.cpp b/src/utils/SkMeshUtils.cpp
new file mode 100644
index 0000000000..0385b99d01
--- /dev/null
+++ b/src/utils/SkMeshUtils.cpp
@@ -0,0 +1,96 @@
+#include "SkMeshUtils.h"
+#include "SkCanvas.h"
+#include "SkPaint.h"
+
+SkMeshIndices::SkMeshIndices() {
+    sk_bzero(this, sizeof(*this));
+}
+
+SkMeshIndices::~SkMeshIndices() {
+    sk_free(fStorage);
+}
+
+bool SkMeshIndices::init(SkPoint tex[], uint16_t indices[],
+                         int texW, int texH, int rows, int cols) {
+    if (rows < 2 || cols < 2) {
+        sk_free(fStorage);
+        fStorage = NULL;
+        fTex = NULL;
+        fIndices = NULL;
+        fTexCount = fIndexCount = 0;
+        return false;
+    }
+
+    sk_free(fStorage);
+    fStorage = NULL;
+
+    fTexCount = rows * cols;
+    rows -= 1;
+    cols -= 1;
+    fIndexCount = rows * cols * 6;
+
+    if (tex) {
+        fTex = tex;
+        fIndices = indices;
+    } else {
+        fStorage = sk_malloc_throw(fTexCount * sizeof(SkPoint) +
+                                   fIndexCount * sizeof(uint16_t));
+        fTex = (SkPoint*)fStorage;
+        fIndices = (uint16_t*)(fTex + fTexCount);
+    }
+
+    // compute the indices
+    {
+        uint16_t* idx = fIndices;
+        int index = 0;
+        for (int y = 0; y < cols; y++) {
+            for (int x = 0; x < rows; x++) {
+                *idx++ = index;
+                *idx++ = index + rows + 1;
+                *idx++ = index + 1;
+                
+                *idx++ = index + 1;
+                *idx++ = index + rows + 1;
+                *idx++ = index + rows + 2;
+                
+                index += 1;
+            }
+            index += 1;
+        }
+    }
+
+    // compute texture coordinates
+    {
+        SkPoint* tex = fTex;
+        const SkScalar dx = SkIntToScalar(texW) / rows;
+        const SkScalar dy = SkIntToScalar(texH) / cols;
+        for (int y = 0; y <= cols; y++) {
+            for (int x = 0; x <= rows; x++) {
+                tex->set(x*dx, y*dy);
+                tex += 1;
+            }
+        }
+    }
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+#include "SkShader.h"
+
+void SkMeshUtils::Draw(SkCanvas* canvas, const SkBitmap& bitmap,
+                       int rows, int cols, const SkPoint verts[],
+                       const SkColor colors[], const SkPaint& paint) {
+    SkMeshIndices idx;
+    
+    if (idx.init(bitmap.width(), bitmap.height(), rows, cols)) {
+        SkPaint p(paint);
+        p.setShader(SkShader::CreateBitmapShader(bitmap,
+                                         SkShader::kClamp_TileMode,
+                                         SkShader::kClamp_TileMode))->unref();
+        canvas->drawVertices(SkCanvas::kTriangles_VertexMode,
+                             rows * cols, verts, idx.tex(), colors, NULL,
+                             idx.indices(), idx.indexCount(), p);
+    }
+}
+