diff options
Diffstat (limited to 'libdimension/png.c')
| -rw-r--r-- | libdimension/png.c | 118 |
1 files changed, 56 insertions, 62 deletions
diff --git a/libdimension/png.c b/libdimension/png.c index 8348e5f..24f8afa 100644 --- a/libdimension/png.c +++ b/libdimension/png.c @@ -30,7 +30,6 @@ #include <stdlib.h> #include <stdint.h> -/* Optimize canvas for PNG exporting */ int dmnsn_png_optimize_canvas(dmnsn_canvas *canvas) { @@ -38,14 +37,14 @@ dmnsn_png_optimize_canvas(dmnsn_canvas *canvas) return 0; } -/** Payload type for PNG write thread callback. */ +/// Payload type for PNG write thread callback. typedef struct { dmnsn_future *future; const dmnsn_canvas *canvas; FILE *file; } dmnsn_png_write_payload; -/** Payload type for PNG read thread callback. */ +/// Payload type for PNG read thread callback. typedef struct { dmnsn_future *future; dmnsn_canvas **canvas; @@ -53,13 +52,11 @@ typedef struct { FILE *file; } dmnsn_png_read_payload; -/** PNG write thread callback. */ +/// PNG write thread callback. static int dmnsn_png_write_canvas_thread(void *ptr); -/** PNG read thread callback. */ +/// PNG read thread callback. static int dmnsn_png_read_canvas_thread(void *ptr); -/* Write a canvas to a png file, using libpng. Return 0 on success, nonzero on - failure. */ int dmnsn_png_write_canvas(const dmnsn_canvas *canvas, FILE *file) { @@ -67,7 +64,6 @@ dmnsn_png_write_canvas(const dmnsn_canvas *canvas, FILE *file) return dmnsn_future_join(future); } -/* Write a canvas to a png file in the background */ dmnsn_future * dmnsn_png_write_canvas_async(const dmnsn_canvas *canvas, FILE *file) { @@ -78,13 +74,13 @@ dmnsn_png_write_canvas_async(const dmnsn_canvas *canvas, FILE *file) payload->canvas = canvas; payload->file = file; - /* Create the worker thread */ + // Create the worker thread dmnsn_new_thread(future, dmnsn_png_write_canvas_thread, payload); return future; } -/* Read a canvas from the PNG file `file'. Return NULL on error. */ +// Read a canvas from the PNG file `file'. Return NULL on error. dmnsn_canvas * dmnsn_png_read_canvas(dmnsn_pool *pool, FILE *file) { @@ -94,7 +90,7 @@ dmnsn_png_read_canvas(dmnsn_pool *pool, FILE *file) return canvas; } -/* Read a canvas from a png file in the background */ +// Read a canvas from a png file in the background dmnsn_future * dmnsn_png_read_canvas_async(dmnsn_canvas **canvas, dmnsn_pool *pool, FILE *file) { @@ -107,17 +103,17 @@ dmnsn_png_read_canvas_async(dmnsn_canvas **canvas, dmnsn_pool *pool, FILE *file) payload->pool = pool; payload->file = file; - /* Create the worker thread */ + // Create the worker thread dmnsn_new_thread(future, dmnsn_png_read_canvas_thread, payload); return future; } -/* - * Thread callbacks - */ +////////////////////// +// Thread callbacks // +////////////////////// -/* Write a PNG file */ +// Write a PNG file static int dmnsn_png_write_canvas_thread(void *ptr) { @@ -131,74 +127,74 @@ dmnsn_png_write_canvas_thread(void *ptr) png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (!png_ptr) { - /* Couldn't create libpng write struct */ + // Couldn't create libpng write struct dmnsn_free(payload); return -1; } png_infop info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { - /* Couldn't create libpng info struct */ + // Couldn't create libpng info struct png_destroy_write_struct(&png_ptr, NULL); dmnsn_free(payload); return -1; } - /* libpng will longjmp here if it encounters an error from here on */ + // libpng will longjmp here if it encounters an error from here on uint16_t *row = NULL; if (setjmp(png_jmpbuf(png_ptr))) { - /* libpng error */ + // libpng error dmnsn_free(row); png_destroy_write_struct(&png_ptr, &info_ptr); dmnsn_free(payload); return -1; } - /* Associate file with the libpng write struct */ + // Associate file with the libpng write struct png_init_io(png_ptr, payload->file); - /* Set header correctly for 16-bit sRGB image */ + // Set header correctly for 16-bit sRGB image png_set_IHDR(png_ptr, info_ptr, width, height, 16, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, PNG_sRGB_INTENT_ABSOLUTE); - /* We think of transparency in the opposite way that PNG does */ + // We think of transparency in the opposite way that PNG does png_set_invert_alpha(png_ptr); - /* Write the info struct */ + // Write the info struct png_write_info(png_ptr, info_ptr); if (dmnsn_is_little_endian()) { - /* We are little-endian; swap the byte order of the pixels */ + // We are little-endian; swap the byte order of the pixels png_set_swap(png_ptr); } - /* Check if we can optimize this */ + // Check if we can optimize this dmnsn_canvas_optimizer *optimizer = dmnsn_canvas_find_optimizer(payload->canvas, dmnsn_rgba16_optimizer_fn); if (optimizer) { for (size_t y = 0; y < height; ++y) { - /* Invert the rows. PNG coordinates are fourth quadrant. */ + // Invert the rows. PNG coordinates are fourth quadrant. uint16_t *row_opt = (uint16_t *)optimizer->ptr + 4*(height - y - 1)*width; png_write_row(png_ptr, (png_bytep)row_opt); dmnsn_future_increment(payload->future); } - /* Finish the PNG file */ + // Finish the PNG file png_write_end(png_ptr, info_ptr); png_destroy_write_struct(&png_ptr, &info_ptr); dmnsn_free(payload); return 0; } - /* Allocate the temporary row of RGBA values */ + // Allocate the temporary row of RGBA values row = dmnsn_malloc(4*sizeof(uint16_t)*width); - /* Write the pixels */ + // Write the pixels for (size_t y = 0; y < height; ++y) { for (size_t x = 0; x < width; ++x) { - /* Invert the rows. PNG coordinates are fourth quadrant. */ + // Invert the rows. PNG coordinates are fourth quadrant. dmnsn_tcolor tcolor = dmnsn_canvas_get_pixel(payload->canvas, x, height - y - 1); tcolor = dmnsn_tcolor_remove_filter(tcolor); @@ -211,12 +207,12 @@ dmnsn_png_write_canvas_thread(void *ptr) row[4*x + 3] = lround(tcolor.T*UINT16_MAX); } - /* Write the row */ + // Write the row png_write_row(png_ptr, (png_bytep)row); dmnsn_future_increment(payload->future); } - /* Finish the PNG file */ + // Finish the PNG file png_write_end(png_ptr, info_ptr); dmnsn_free(row); @@ -225,18 +221,18 @@ dmnsn_png_write_canvas_thread(void *ptr) return 0; } -/** Thread-specific pointer to the appropriate dmnsn_future* for - dmnsn_png_read_row_callback. */ +/// Thread-specific pointer to the appropriate dmnsn_future* for +/// dmnsn_png_read_row_callback. static __thread dmnsn_future *dmnsn_tl_png_read_future; -/** Callback to increment the progress after a row has been read. */ +/// Callback to increment the progress after a row has been read. static void dmnsn_png_read_row_callback(png_structp png_ptr, png_uint_32 row, int pass) { dmnsn_future_increment(dmnsn_tl_png_read_future); } -/* Read a PNG file */ +// Read a PNG file static int dmnsn_png_read_canvas_thread(void *ptr) { @@ -249,13 +245,13 @@ dmnsn_png_read_canvas_thread(void *ptr) return -1; } if (png_sig_cmp(header, 0, 8)) { - /* payload->file is not a PNG file */ + // payload->file is not a PNG file dmnsn_free(payload); errno = EINVAL; return -1; } - /* Create the libpng read struct */ + // Create the libpng read struct png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (!png_ptr) { @@ -263,7 +259,7 @@ dmnsn_png_read_canvas_thread(void *ptr) return -1; } - /* Create the libpng info struct */ + // Create the libpng info struct png_infop info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { png_destroy_read_struct(&png_ptr, NULL, NULL); @@ -271,11 +267,11 @@ dmnsn_png_read_canvas_thread(void *ptr) return -1; } - /* libpng will longjmp here if it encounters an error from here on */ + // libpng will longjmp here if it encounters an error from here on png_bytep image = NULL; png_bytep *row_pointers = NULL; if (setjmp(png_jmpbuf(png_ptr))) { - /* libpng error */ + // libpng error dmnsn_free(row_pointers); dmnsn_free(image); png_destroy_read_struct(&png_ptr, &info_ptr, NULL); @@ -283,15 +279,15 @@ dmnsn_png_read_canvas_thread(void *ptr) return -1; } - /* Associate the read struct with the file, and tell it we've already checked - 8 bytes of signature */ + // Associate the read struct with the file, and tell it we've already checked + // 8 bytes of signature png_init_io(png_ptr, payload->file); png_set_sig_bytes(png_ptr, 8); - /* Read the PNG header into info struct */ + // Read the PNG header into info struct png_read_info(png_ptr, info_ptr); - /* Get useful information from the info struct */ + // Get useful information from the info struct png_uint_32 width, height; int bit_depth, color_type, interlace_type, compression_type, filter_method; png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, @@ -301,12 +297,10 @@ dmnsn_png_read_canvas_thread(void *ptr) dmnsn_future_set_total(payload->future, (number_of_passes + 1)*height); png_set_read_status_fn(png_ptr, dmnsn_png_read_row_callback); - /* - * - Convert paletted images to RGB. - * - Convert a tRNS chunk to an alpha channel - * - Convert grayscale to RGB - * - Invert the alpha channel - */ + // - Convert paletted images to RGB. + // - Convert a tRNS chunk to an alpha channel + // - Convert grayscale to RGB + // - Invert the alpha channel if (color_type == PNG_COLOR_TYPE_PALETTE) { png_set_palette_to_rgb(png_ptr); } @@ -320,32 +314,32 @@ dmnsn_png_read_canvas_thread(void *ptr) } png_set_invert_alpha(png_ptr); - /* Update the info struct */ + // Update the info struct png_read_update_info(png_ptr, info_ptr); - /* Get bytes/image row */ + // Get bytes/image row png_uint_32 rowbytes = png_get_rowbytes(png_ptr, info_ptr); - /* Allocate the temporary image buffer */ + // Allocate the temporary image buffer image = dmnsn_malloc(rowbytes*height); - /* Allocate and set an array of pointers to rows in image */ + // Allocate and set an array of pointers to rows in image row_pointers = dmnsn_malloc(sizeof(png_bytep)*height); for (size_t y = 0; y < height; ++y) { row_pointers[y] = image + y*rowbytes; } - /* Read the image to memory all at once. At the expense of greater memory - use, this handles interlacing for us. */ + // Read the image to memory all at once. At the expense of greater memory + // use, this handles interlacing for us. png_read_image(png_ptr, row_pointers); - /* Allocate the canvas */ + // Allocate the canvas *payload->canvas = dmnsn_new_canvas(payload->pool, width, height); - /* Now we convert the image to our canvas format. This depends on the image - bit depth (which has been scaled up to at least 8 or 16), and the presence - of an alpha channel. */ + // Now we convert the image to our canvas format. This depends on the image + // bit depth (which has been scaled up to at least 8 or 16), and the presence + // of an alpha channel. for (size_t y = 0; y < height; ++y) { for (size_t x = 0; x < width; ++x) { dmnsn_tcolor tcolor; |