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png_wrapper : use libpng interface instead of raw png_info pointers
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(redoing c3022bb due to accidental
reformatting)
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joshua committed Jun 7, 2012
1 parent c3022bb commit fdec266
Showing 1 changed file with 184 additions and 149 deletions.
333 changes: 184 additions & 149 deletions src/gfx/png_wrapper.cc
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Expand Up @@ -42,161 +42,196 @@ namespace gfx
// Functions for overriding reading/writing png using iostreams
void user_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
ifstream &file = *(ifstream *) (((png_get_io_ptr(png_ptr))));
file.read((char*) ((data)), length);
}
ifstream &file = *(ifstream *)(png_get_io_ptr(png_ptr));
file.read((char *)data,length);
}

void user_write_data(png_structp png_ptr, png_bytep data, png_size_t length) {
ofstream& file = *(ofstream*) (((png_get_io_ptr(png_ptr))));
file.write((char*) ((data)), length);
}
void user_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
ofstream &file = *(ofstream*)(png_get_io_ptr(png_ptr));
file.write((char *)data, length);
}

void user_flush_data(png_structp png_ptr) {
ofstream& file = *(ofstream*) (((png_get_io_ptr(png_ptr))));
file.flush();
}
void user_flush_data(png_structp png_ptr)
{
ofstream &file = *(ofstream*)(png_get_io_ptr(png_ptr));
file.flush();
}

void * png::get (ifstream & file, u_int16 & length, u_int16 & height, bool * alpha)
{
const int headerbytes = 8; //This is used to read the file and make sure its a png... can be 1-8
png_byte header[headerbytes];
png_structp png_ptr;
png_infop info_ptr;

int number_of_passes;
png_bytep * row_pointers;

/* open file and test for it being a png */
file.read((char *)header, headerbytes);
if (png_sig_cmp(header, 0, headerbytes))
{
LOG(ERROR) << logging::indent() << "[read_png_file] File is not recognized as a PNG file";
return NULL;
}

/* initialize stuff */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
{
LOG(ERROR) << logging::indent() << "[read_png_file] png_create_read_struct failed";
return NULL;
}

void* png::get(ifstream& file, u_int16& length, u_int16& height, bool* alpha) {
const int headerbytes = 8; //This is used to read the file and make sure its a png... can be 1-8
png_byte header[headerbytes];
png_structp png_ptr;
png_infop info_ptr;
int number_of_passes;
png_bytep* row_pointers;
/* open file and test for it being a png */
file.read((char*) ((header)), headerbytes);
if (png_sig_cmp(header, 0, headerbytes)) {
LOG(ERROR) << logging::indent()
<< "[read_png_file] File is not recognized as a PNG file";
return NULL;
}
/* initialize stuff */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr) {
LOG(ERROR) << logging::indent()
<< "[read_png_file] png_create_read_struct failed";
return NULL;
}
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
LOG(ERROR) << logging::indent()
<< "[read_png_file] png_create_info_struct failed";
png_destroy_read_struct(&png_ptr, NULL, NULL);
return NULL;
}
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
LOG(ERROR) << logging::indent()
<< "[read_png_file] Error during init_io";
return NULL;
}
png_set_read_fn(png_ptr, &file, user_read_data);
png_set_sig_bytes(png_ptr, headerbytes);
png_read_info(png_ptr, info_ptr);
length = png_get_image_width(png_ptr, info_ptr);
height = png_get_image_height(png_ptr, info_ptr);
number_of_passes = png_set_interlace_handling(png_ptr);
png_read_update_info(png_ptr, info_ptr);
/* read file */
if (setjmp(png_jmpbuf(png_ptr))) {
LOG(ERROR) << logging::indent()
<< "[read_png_file] Error during read_image";
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return NULL;
}
*alpha = (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_RGBA);
const int bytes_per_pixel = (*alpha) ? 4 : 3;
char* image = (char*) ((calloc(length * height, bytes_per_pixel)));
int idx = 0;
switch (png_get_color_type(png_ptr, info_ptr)) {
case PNG_COLOR_TYPE_RGBA: {
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
LOG(ERROR) << logging::indent() << "[read_png_file] png_create_info_struct failed";
png_destroy_read_struct(&png_ptr, NULL, NULL);
return NULL;
}

if (setjmp(png_jmpbuf(png_ptr)))
{
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
LOG(ERROR) << logging::indent() << "[read_png_file] Error during init_io";
return NULL;
}

png_set_read_fn(png_ptr, &file, user_read_data);
png_set_sig_bytes(png_ptr, headerbytes);

png_read_info(png_ptr, info_ptr);

length = png_get_image_width(png_ptr, info_ptr);
height = png_get_image_height(png_ptr, info_ptr);

number_of_passes = png_set_interlace_handling(png_ptr);
png_read_update_info(png_ptr, info_ptr);

/* read file */
if (setjmp(png_jmpbuf(png_ptr)))
{
LOG(ERROR) << logging::indent() << "[read_png_file] Error during read_image";
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return NULL;
}

*alpha = (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_RGBA);
const int bytes_per_pixel = (*alpha) ? 4 : 3;
char *image = (char *)calloc (length * height, bytes_per_pixel);
int idx = 0;

switch (png_get_color_type(png_ptr, info_ptr))
{
case PNG_COLOR_TYPE_RGBA:
{
#ifdef __BIG_ENDIAN__
// read pixels in ARGB format instead of RGBA
png_set_swap_alpha(png_ptr);
// read pixels in ARGB format instead of RGBA
png_set_swap_alpha(png_ptr);
#endif
// fall through
}
case PNG_COLOR_TYPE_RGB: {
row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
for (int y = 0; y < height; y++)
row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr, info_ptr));

png_read_image(png_ptr, row_pointers);

const int line_buf_length = bytes_per_pixel * length;

for (int y = 0; y < height; y++) {
const png_byte* row = row_pointers[y];

memcpy(image + idx, row, line_buf_length);
idx += line_buf_length;

free(row_pointers[y]);
}
free(row_pointers);
break;
}
default:
LOG(ERROR) << logging::indent()
<< "[read_png_file] color_type of input file must be PNG_COLOR_TYPE_RGBA (is "
<< png_get_color_type(png_ptr, info_ptr) << ")";
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return NULL;
}
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return image;
}
// fall through
}
case PNG_COLOR_TYPE_RGB:
{
row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
for (int y=0; y<height; y++)
row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr, info_ptr));

png_read_image(png_ptr, row_pointers);

const int line_buf_length = bytes_per_pixel * length;

for (int y=0; y<height; y++)
{
const png_byte* row = row_pointers[y];

memcpy(image + idx, row, line_buf_length);
idx += line_buf_length;

free(row_pointers[y]);
}
free(row_pointers);
break;
}
default:
LOG(ERROR) << logging::indent() << "[read_png_file] color_type of input file must be PNG_COLOR_TYPE_RGBA (is " << png_get_color_type(png_ptr, info_ptr) << ")";
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return NULL;
}

void png::put(ofstream& file, const char* image, u_int16 length, u_int16 height,
bool alpha) {
png_structp png_ptr;
png_infop info_ptr;
png_bytep* row_pointers;
/* initialize stuff */
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr) {
LOG(ERROR) << logging::indent()
<< "[write_png_file] png_create_write_struct failed";
return;
}
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
LOG(ERROR) << logging::indent()
<< "[write_png_file] png_create_info_struct failed";
png_destroy_write_struct(&png_ptr, NULL);
return;
}
if (setjmp(png_jmpbuf(png_ptr))) {
LOG(ERROR) << logging::indent()
<< "[write_png_file] Error during init_io";
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}
png_set_write_fn(png_ptr, &file, user_write_data, user_flush_data);
/* write header */
if (setjmp(png_jmpbuf(png_ptr))) {
LOG(ERROR) << logging::indent()
<< "[write_png_file] Error during writing header";
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}
int color_type = alpha ? PNG_COLOR_TYPE_RGBA : PNG_COLOR_TYPE_RGB;
png_set_IHDR(png_ptr, info_ptr, length, height, 8, color_type,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
PNG_FILTER_TYPE_BASE);
png_write_info(png_ptr, info_ptr);
/* write bytes */
if (setjmp(png_jmpbuf(png_ptr))) {
LOG(ERROR) << logging::indent()
<< "[write_png_file] Error during writing bytes";
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}
// write pixels in ARGB format instead of RGBA
int idx = 0;
row_pointers = (png_bytep*) ((malloc(sizeof(png_bytep) * height)));
for (int y = 0; y < height; y++) {
row_pointers[y] = (png_byte*) ((malloc(png_get_rowbytes(png_ptr, info_ptr))));
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return image;
}

void png::put (ofstream & file, const char *image, u_int16 length, u_int16 height, bool alpha)
{
png_structp png_ptr;
png_infop info_ptr;
png_bytep * row_pointers;

/* initialize stuff */
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
{
LOG(ERROR) << logging::indent() << "[write_png_file] png_create_write_struct failed";
return;
}

info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
LOG(ERROR) << logging::indent() << "[write_png_file] png_create_info_struct failed";
png_destroy_write_struct(&png_ptr, NULL);
return;
}

if (setjmp(png_jmpbuf(png_ptr)))
{
LOG(ERROR) << logging::indent() << "[write_png_file] Error during init_io";
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}

png_set_write_fn(png_ptr, &file, user_write_data, user_flush_data);

/* write header */
if (setjmp(png_jmpbuf(png_ptr)))
{
LOG(ERROR) << logging::indent() << "[write_png_file] Error during writing header";
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}

int color_type = alpha ? PNG_COLOR_TYPE_RGBA : PNG_COLOR_TYPE_RGB;
png_set_IHDR(png_ptr, info_ptr, length, height, 8, color_type,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
PNG_FILTER_TYPE_BASE);

png_write_info(png_ptr, info_ptr);

/* write bytes */
if (setjmp(png_jmpbuf(png_ptr)))
{
LOG(ERROR) << logging::indent() << "[write_png_file] Error during writing bytes";
png_destroy_write_struct(&png_ptr, &info_ptr);
return;
}

#ifdef __BIG_ENDIAN__
if (alpha)
{
// write pixels in ARGB format instead of RGBA
png_set_swap_alpha(png_ptr);
}
#endif

int idx = 0;
row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
for (int y=0; y<height; y++)
{
row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr, info_ptr));
png_byte* row = row_pointers[y];
for (int x=0; x<length; x++)
{
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