michael@0: 
michael@0: /*
michael@0:  * Copyright 2011 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: #include "SkMeshUtils.h"
michael@0: #include "SkCanvas.h"
michael@0: #include "SkPaint.h"
michael@0: 
michael@0: SkMeshIndices::SkMeshIndices() {
michael@0:     sk_bzero(this, sizeof(*this));
michael@0: }
michael@0: 
michael@0: SkMeshIndices::~SkMeshIndices() {
michael@0:     sk_free(fStorage);
michael@0: }
michael@0: 
michael@0: bool SkMeshIndices::init(SkPoint tex[], uint16_t indices[],
michael@0:                          int texW, int texH, int rows, int cols) {
michael@0:     if (rows < 2 || cols < 2) {
michael@0:         sk_free(fStorage);
michael@0:         fStorage = NULL;
michael@0:         fTex = NULL;
michael@0:         fIndices = NULL;
michael@0:         fTexCount = fIndexCount = 0;
michael@0:         return false;
michael@0:     }
michael@0: 
michael@0:     sk_free(fStorage);
michael@0:     fStorage = NULL;
michael@0: 
michael@0:     fTexCount = rows * cols;
michael@0:     rows -= 1;
michael@0:     cols -= 1;
michael@0:     fIndexCount = rows * cols * 6;
michael@0: 
michael@0:     if (tex) {
michael@0:         fTex = tex;
michael@0:         fIndices = indices;
michael@0:     } else {
michael@0:         fStorage = sk_malloc_throw(fTexCount * sizeof(SkPoint) +
michael@0:                                    fIndexCount * sizeof(uint16_t));
michael@0:         fTex = (SkPoint*)fStorage;
michael@0:         fIndices = (uint16_t*)(fTex + fTexCount);
michael@0:     }
michael@0: 
michael@0:     // compute the indices
michael@0:     {
michael@0:         uint16_t* idx = fIndices;
michael@0:         int index = 0;
michael@0:         for (int y = 0; y < cols; y++) {
michael@0:             for (int x = 0; x < rows; x++) {
michael@0:                 *idx++ = index;
michael@0:                 *idx++ = index + rows + 1;
michael@0:                 *idx++ = index + 1;
michael@0: 
michael@0:                 *idx++ = index + 1;
michael@0:                 *idx++ = index + rows + 1;
michael@0:                 *idx++ = index + rows + 2;
michael@0: 
michael@0:                 index += 1;
michael@0:             }
michael@0:             index += 1;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     // compute texture coordinates
michael@0:     {
michael@0:         SkPoint* tex = fTex;
michael@0:         const SkScalar dx = SkIntToScalar(texW) / rows;
michael@0:         const SkScalar dy = SkIntToScalar(texH) / cols;
michael@0:         for (int y = 0; y <= cols; y++) {
michael@0:             for (int x = 0; x <= rows; x++) {
michael@0:                 tex->set(x*dx, y*dy);
michael@0:                 tex += 1;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: #include "SkShader.h"
michael@0: 
michael@0: void SkMeshUtils::Draw(SkCanvas* canvas, const SkBitmap& bitmap,
michael@0:                        int rows, int cols, const SkPoint verts[],
michael@0:                        const SkColor colors[], const SkPaint& paint) {
michael@0:     SkMeshIndices idx;
michael@0: 
michael@0:     if (idx.init(bitmap.width(), bitmap.height(), rows, cols)) {
michael@0:         SkPaint p(paint);
michael@0:         p.setShader(SkShader::CreateBitmapShader(bitmap,
michael@0:                                          SkShader::kClamp_TileMode,
michael@0:                                          SkShader::kClamp_TileMode))->unref();
michael@0:         canvas->drawVertices(SkCanvas::kTriangles_VertexMode,
michael@0:                              rows * cols, verts, idx.tex(), colors, NULL,
michael@0:                              idx.indices(), idx.indexCount(), p);
michael@0:     }
michael@0: }