1/* Copyright (c) 2013-2014 Jeffrey Pfau
  2 *
  3 * This Source Code Form is subject to the terms of the Mozilla Public
  4 * License, v. 2.0. If a copy of the MPL was not distributed with this
  5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  6#include "util/png-io.h"
  7
  8#ifdef USE_PNG
  9
 10#include "vfs.h"
 11
 12static void _pngWrite(png_structp png, png_bytep buffer, png_size_t size) {
 13	struct VFile* vf = png_get_io_ptr(png);
 14	size_t written = vf->write(vf, buffer, size);
 15	if (written != size) {
 16		png_error(png, "Could not write PNG");
 17	}
 18}
 19
 20static void _pngRead(png_structp png, png_bytep buffer, png_size_t size) {
 21	struct VFile* vf = png_get_io_ptr(png);
 22	size_t read = vf->read(vf, buffer, size);
 23	if (read != size) {
 24		png_error(png, "Could not read PNG");
 25	}
 26}
 27
 28png_structp PNGWriteOpen(struct VFile* source) {
 29	png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
 30	if (!png) {
 31		return 0;
 32	}
 33	if (setjmp(png_jmpbuf(png))) {
 34		png_destroy_write_struct(&png, 0);
 35		return 0;
 36	}
 37	png_set_write_fn(png, source, _pngWrite, 0);
 38	return png;
 39}
 40
 41png_infop PNGWriteHeader(png_structp png, unsigned width, unsigned height) {
 42	png_infop info = png_create_info_struct(png);
 43	if (!info) {
 44		return 0;
 45	}
 46	if (setjmp(png_jmpbuf(png))) {
 47		return 0;
 48	}
 49	png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 50	png_write_info(png, info);
 51	return info;
 52}
 53
 54bool PNGWritePixels(png_structp png, unsigned width, unsigned height, unsigned stride, const void* pixels) {
 55	png_bytep row = malloc(sizeof(png_byte) * width * 3);
 56	if (!row) {
 57		return false;
 58	}
 59	const png_byte* pixelData = pixels;
 60	if (setjmp(png_jmpbuf(png))) {
 61		free(row);
 62		return false;
 63	}
 64	unsigned i;
 65	for (i = 0; i < height; ++i) {
 66		unsigned x;
 67		for (x = 0; x < width; ++x) {
 68#ifdef COLOR_16_BIT
 69			uint16_t c = ((uint16_t*) pixelData)[stride * i + x];
 70#ifdef COLOR_5_6_5
 71			row[x * 3] = (c >> 8) & 0xF8;
 72			row[x * 3 + 1] = (c >> 3) & 0xFC;
 73			row[x * 3 + 2] = (c << 3) & 0xF8;
 74#else
 75			row[x * ] = (c >> 7) & 0xF8;
 76			row[x *  + 1] = (c >> 2) & 0xF8;
 77			row[x *  + 2] = (c << 3) & 0xF8;
 78#endif
 79#else
 80#ifdef __BIG_ENDIAN__
 81			row[x * 3] = pixelData[stride * i * 4 + x * 4 + 3];
 82			row[x * 3 + 1] = pixelData[stride * i * 4 + x * 4 + 2];
 83			row[x * 3 + 2] = pixelData[stride * i * 4 + x * 4 + 1];
 84#else
 85			row[x * 3] = pixelData[stride * i * 4 + x * 4];
 86			row[x * 3 + 1] = pixelData[stride * i * 4 + x * 4 + 1];
 87			row[x * 3 + 2] = pixelData[stride * i * 4 + x * 4 + 2];
 88#endif
 89#endif
 90		}
 91		png_write_row(png, row);
 92	}
 93	free(row);
 94	return true;
 95}
 96
 97bool PNGWriteCustomChunk(png_structp png, const char* name, size_t size, void* data) {
 98	char realName[5];
 99	strncpy(realName, name, 4);
100	realName[0] = tolower((int) realName[0]);
101	realName[1] = tolower((int) realName[1]);
102	realName[4] = '\0';
103	if (setjmp(png_jmpbuf(png))) {
104		return false;
105	}
106	png_write_chunk(png, (png_bytep) realName, data, size);
107	return true;
108}
109
110void PNGWriteClose(png_structp png, png_infop info) {
111	if (!setjmp(png_jmpbuf(png))) {
112		png_write_end(png, info);
113	}
114	png_destroy_write_struct(&png, &info);
115}
116
117bool isPNG(struct VFile* source) {
118	png_byte header[PNG_HEADER_BYTES];
119	source->read(source, header, PNG_HEADER_BYTES);
120	return !png_sig_cmp(header, 0, PNG_HEADER_BYTES);
121}
122
123png_structp PNGReadOpen(struct VFile* source, unsigned offset) {
124	png_structp png = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
125	if (!png) {
126		return 0;
127	}
128	if (setjmp(png_jmpbuf(png))) {
129		png_destroy_read_struct(&png, 0, 0);
130		return 0;
131	}
132	png_set_read_fn(png, source, _pngRead);
133	png_set_sig_bytes(png, offset);
134	return png;
135}
136
137bool PNGInstallChunkHandler(png_structp png, void* context, ChunkHandler handler, const char* chunkName) {
138	if (setjmp(png_jmpbuf(png))) {
139		return false;
140	}
141	png_set_read_user_chunk_fn(png, context, handler);
142	int len = strlen(chunkName);
143	int chunks = 0;
144	char* chunkList = strdup(chunkName);
145	int i;
146	for (i = 4; i <= len; i += 5) {
147		chunkList[i] = '\0';
148		++chunks;
149	}
150	png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS, (png_bytep) chunkList, chunks);
151	free(chunkList);
152	return true;
153}
154
155bool PNGReadHeader(png_structp png, png_infop info) {
156	if (setjmp(png_jmpbuf(png))) {
157		return false;
158	}
159	png_read_info(png, info);
160	return true;
161}
162
163bool PNGIgnorePixels(png_structp png, png_infop info) {
164	if (setjmp(png_jmpbuf(png))) {
165		return false;
166	}
167
168	unsigned height = png_get_image_height(png, info);
169	unsigned i;
170	for (i = 0; i < height; ++i) {
171		png_read_row(png, 0, 0);
172	}
173	return true;
174}
175
176bool PNGReadPixels(png_structp png, png_infop info, void* pixels, unsigned width, unsigned height, unsigned stride) {
177	if (setjmp(png_jmpbuf(png))) {
178		return false;
179	}
180
181	uint8_t* pixelData = pixels;
182	unsigned pngHeight = png_get_image_height(png, info);
183	if (height < pngHeight) {
184		pngHeight = height;
185	}
186
187	unsigned pngWidth = png_get_image_width(png, info);
188	if (width < pngWidth) {
189		pngWidth = width;
190	}
191
192	unsigned i;
193	png_bytep row = malloc(png_get_rowbytes(png, info));
194	for (i = 0; i < pngHeight; ++i) {
195		png_read_row(png, row, 0);
196		unsigned x;
197		for (x = 0; x < pngWidth; ++x) {
198#ifdef COLOR_16_BIT
199			uint16_t c = row[x * 3 + 2] >> 3;
200#ifdef COLOR_5_6_5
201			c |= (row[x * 3 + 1] << 3) & 0x7E0;
202			c |= (row[x * 3] << 8) & 0xF800;
203#else
204			c |= (row[x * 3 + 1] << 2) & 0x3E0;
205			c |= (row[x * 3] << 7) & 0x7C00;
206#endif
207			((uint16_t*) pixelData)[stride * i + x] = c;
208#else
209#if __BIG_ENDIAN__
210			pixelData[stride * i * 4 + x * 4 + 3] = row[x * 3];
211			pixelData[stride * i * 4 + x * 4 + 2] = row[x * 3 + 1];
212			pixelData[stride * i * 4 + x * 4 + 1] = row[x * 3 + 2];
213			pixelData[stride * i * 4 + x * 4] = 0xFF;
214#else
215			pixelData[stride * i * 4 + x * 4] = row[x * 3];
216			pixelData[stride * i * 4 + x * 4 + 1] = row[x * 3 + 1];
217			pixelData[stride * i * 4 + x * 4 + 2] = row[x * 3 + 2];
218			pixelData[stride * i * 4 + x * 4 + 3] = 0xFF;
219#endif
220#endif
221		}
222	}
223	free(row);
224	return true;
225}
226
227bool PNGReadFooter(png_structp png, png_infop end) {
228	if (setjmp(png_jmpbuf(png))) {
229		return false;
230	}
231	png_read_end(png, end);
232	return true;
233}
234
235void PNGReadClose(png_structp png, png_infop info, png_infop end) {
236	png_destroy_read_struct(&png, &info, &end);
237}
238
239#endif