update on boundary patches
git-svn-id: http://skia.googlecode.com/svn/trunk@409 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/utils/SkMeshUtils.cpp b/src/utils/SkMeshUtils.cpp
new file mode 100644
index 0000000..0385b99
--- /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);
+ }
+}
+