blob: 27eccc250d407c6f76a95dc75206fec81ecb7c4a [file] [log] [blame]
/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#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 = nullptr;
fTex = nullptr;
fIndices = nullptr;
fTexCount = fIndexCount = 0;
return false;
}
sk_free(fStorage);
fStorage = nullptr;
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::MakeBitmapShader(bitmap,
SkShader::kClamp_TileMode,
SkShader::kClamp_TileMode));
canvas->drawVertices(SkCanvas::kTriangles_VertexMode,
rows * cols, verts, idx.tex(), colors, nullptr,
idx.indices(), idx.indexCount(), p);
}
}