1/*
2 * Copyright 2016 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "Request.h"
9
10#include "png.h"
11
12const int Request::kImageWidth = 1920;
13const int Request::kImageHeight = 1080;
14
15static void write_png_callback(png_structp png_ptr, png_bytep data, png_size_t length) {
16    SkWStream* out = (SkWStream*) png_get_io_ptr(png_ptr);
17    out->write(data, length);
18}
19
20static void write_png(const png_bytep rgba, png_uint_32 width, png_uint_32 height, SkWStream& out) {
21    png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
22    SkASSERT(png != nullptr);
23    png_infop info_ptr = png_create_info_struct(png);
24    SkASSERT(info_ptr != nullptr);
25    if (setjmp(png_jmpbuf(png))) {
26        SkFAIL("png encode error");
27    }
28    png_set_IHDR(png, info_ptr, width, height, 8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
29                 PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
30    png_set_compression_level(png, 1);
31    png_bytepp rows = (png_bytepp) sk_malloc_throw(height * sizeof(png_byte*));
32    png_bytep pixels = (png_bytep) sk_malloc_throw(width * height * 3);
33    for (png_size_t y = 0; y < height; ++y) {
34        const png_bytep src = rgba + y * width * 4;
35        rows[y] = pixels + y * width * 3;
36        // convert from RGBA to RGB
37        for (png_size_t x = 0; x < width; ++x) {
38            rows[y][x * 3] = src[x * 4];
39            rows[y][x * 3 + 1] = src[x * 4 + 1];
40            rows[y][x * 3 + 2] = src[x * 4 + 2];
41        }
42    }
43    png_set_filter(png, 0, PNG_NO_FILTERS);
44    png_set_rows(png, info_ptr, &rows[0]);
45    png_set_write_fn(png, &out, write_png_callback, NULL);
46    png_write_png(png, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
47    png_destroy_write_struct(&png, NULL);
48    sk_free(rows);
49}
50
51SkBitmap* Request::getBitmapFromCanvas(SkCanvas* canvas) {
52    SkBitmap* bmp = new SkBitmap();
53    SkImageInfo info = SkImageInfo::Make(kImageWidth, kImageHeight, kRGBA_8888_SkColorType,
54                kOpaque_SkAlphaType);
55    bmp->setInfo(info);
56    if (!canvas->readPixels(bmp, 0, 0)) {
57        fprintf(stderr, "Can't read pixels\n");
58        return nullptr;
59    }
60    return bmp;
61}
62
63SkData* Request::writeCanvasToPng(SkCanvas* canvas) {
64    // capture pixels
65    SkAutoTDelete<SkBitmap> bmp(getBitmapFromCanvas(canvas));
66    SkASSERT(bmp);
67
68    // write to png
69    SkDynamicMemoryWStream buffer;
70    write_png((const png_bytep) bmp->getPixels(), bmp->width(), bmp->height(), buffer);
71    return buffer.copyToData();
72}
73
74SkCanvas* Request::getCanvas() {
75    GrContextFactory* factory = fContextFactory;
76    SkGLContext* gl = factory->getContextInfo(GrContextFactory::kNative_GLContextType,
77                                              GrContextFactory::kNone_GLContextOptions).fGLContext;
78    gl->makeCurrent();
79    SkASSERT(fDebugCanvas);
80    SkCanvas* target = fSurface->getCanvas();
81    return target;
82}
83
84void Request::drawToCanvas(int n) {
85    SkCanvas* target = this->getCanvas();
86    fDebugCanvas->drawTo(target, n);
87}
88
89SkData* Request::drawToPng(int n) {
90    this->drawToCanvas(n);
91    return writeCanvasToPng(this->getCanvas());
92}
93
94SkSurface* Request::createCPUSurface() {
95    SkImageInfo info = SkImageInfo::Make(kImageWidth, kImageHeight, kN32_SkColorType,
96                                         kPremul_SkAlphaType);
97    return SkSurface::NewRaster(info);
98}
99
100SkSurface* Request::createGPUSurface() {
101    GrContext* context = fContextFactory->get(GrContextFactory::kNative_GLContextType,
102                                              GrContextFactory::kNone_GLContextOptions);
103    int maxRTSize = context->caps()->maxRenderTargetSize();
104    SkImageInfo info = SkImageInfo::Make(SkTMin(kImageWidth, maxRTSize),
105                                         SkTMin(kImageHeight, maxRTSize),
106                                         kN32_SkColorType, kPremul_SkAlphaType);
107    uint32_t flags = 0;
108    SkSurfaceProps props(flags, SkSurfaceProps::kLegacyFontHost_InitType);
109    SkSurface* surface = SkSurface::NewRenderTarget(context, SkBudgeted::kNo, info, 0,
110                                                    &props);
111    return surface;
112}
113
114