diff options
Diffstat (limited to 'tools/rsfont/convert_png.c')
| -rw-r--r-- | tools/rsfont/convert_png.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/tools/rsfont/convert_png.c b/tools/rsfont/convert_png.c new file mode 100644 index 0000000..f6a3080 --- /dev/null +++ b/tools/rsfont/convert_png.c @@ -0,0 +1,169 @@ +// Copyright (c) 2015 YamaArashi + +#include <stdio.h> +#include <setjmp.h> +#include <png.h> +#include "global.h" +#include "convert_png.h" +#include "gfx.h" + +void ReadPng(char *path, struct Image *image) +{ + FILE *fp = fopen(path, "rb"); + + if (fp == NULL) + FATAL_ERROR("Failed to open \"%s\" for reading.\n", path); + + unsigned char sig[8]; + + if (fread(sig, 8, 1, fp) != 1) + FATAL_ERROR("Failed to read PNG signature from \"%s\".\n", path); + + if (png_sig_cmp(sig, 0, 8)) + FATAL_ERROR("\"%s\" does not have a valid PNG signature.\n", path); + + png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); + + if (!png_ptr) + FATAL_ERROR("Failed to create PNG read struct.\n"); + + png_infop info_ptr = png_create_info_struct(png_ptr); + + if (!info_ptr) + FATAL_ERROR("Failed to create PNG info struct.\n"); + + if (setjmp(png_jmpbuf(png_ptr))) + FATAL_ERROR("Failed to init I/O for reading \"%s\".\n", path); + + png_init_io(png_ptr, fp); + png_set_sig_bytes(png_ptr, 8); + png_read_info(png_ptr, info_ptr); + + int bit_depth = png_get_bit_depth(png_ptr, info_ptr); + + if (bit_depth != image->bitDepth) + FATAL_ERROR("\"%s\" has a bit depth of %d, but the expected bit depth is %d.\n", path, bit_depth, image->bitDepth); + + int color_type = png_get_color_type(png_ptr, info_ptr); + + if (color_type != PNG_COLOR_TYPE_GRAY && color_type != PNG_COLOR_TYPE_PALETTE) + FATAL_ERROR("\"%s\" has an unsupported color type.\n", path); + + // Check if the image has a palette so that we can tell if the colors need to be inverted later. + // Don't read the palette because it's not needed for now. + image->hasPalette = (color_type == PNG_COLOR_TYPE_PALETTE); + + image->width = png_get_image_width(png_ptr, info_ptr); + image->height = png_get_image_height(png_ptr, info_ptr); + + int rowbytes = png_get_rowbytes(png_ptr, info_ptr); + + image->pixels = malloc(image->height * rowbytes); + + if (image->pixels == NULL) + FATAL_ERROR("Failed to allocate pixel buffer.\n"); + + png_bytepp row_pointers = malloc(image->height * sizeof(png_bytep)); + + if (row_pointers == NULL) + FATAL_ERROR("Failed to allocate row pointers.\n"); + + for (int i = 0; i < image->height; i++) + row_pointers[i] = (png_bytep)(image->pixels + (i * rowbytes)); + + if (setjmp(png_jmpbuf(png_ptr))) + FATAL_ERROR("Error reading from \"%s\".\n", path); + + png_read_image(png_ptr, row_pointers); + + png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + + free(row_pointers); + fclose(fp); +} + +void SetPngPalette(png_structp png_ptr, png_infop info_ptr, struct Palette *palette) +{ + png_colorp colors = malloc(palette->numColors * sizeof(png_color)); + + if (colors == NULL) + FATAL_ERROR("Failed to allocate PNG palette.\n"); + + for (int i = 0; i < palette->numColors; i++) { + colors[i].red = palette->colors[i].red; + colors[i].green = palette->colors[i].green; + colors[i].blue = palette->colors[i].blue; + } + + png_set_PLTE(png_ptr, info_ptr, colors, palette->numColors); + + free(colors); +} + +void WritePng(char *path, struct Image *image) +{ + FILE *fp = fopen(path, "wb"); + + if (fp == NULL) + FATAL_ERROR("Failed to open \"%s\" for writing.\n", path); + + png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); + + if (!png_ptr) + FATAL_ERROR("Failed to create PNG write struct.\n"); + + png_infop info_ptr = png_create_info_struct(png_ptr); + + if (!info_ptr) + FATAL_ERROR("Failed to create PNG info struct.\n"); + + if (setjmp(png_jmpbuf(png_ptr))) + FATAL_ERROR("Failed to init I/O for writing \"%s\".\n", path); + + png_init_io(png_ptr, fp); + + if (setjmp(png_jmpbuf(png_ptr))) + FATAL_ERROR("Error writing header for \"%s\".\n", path); + + int color_type = image->hasPalette ? PNG_COLOR_TYPE_PALETTE : PNG_COLOR_TYPE_GRAY; + + png_set_IHDR(png_ptr, info_ptr, image->width, image->height, + image->bitDepth, color_type, PNG_INTERLACE_NONE, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + if (image->hasPalette) { + SetPngPalette(png_ptr, info_ptr, &image->palette); + + if (image->hasTransparency) { + png_byte trans = 0; + png_set_tRNS(png_ptr, info_ptr, &trans, 1, 0); + } + } + + png_write_info(png_ptr, info_ptr); + + png_bytepp row_pointers = malloc(image->height * sizeof(png_bytep)); + + if (row_pointers == NULL) + FATAL_ERROR("Failed to allocate row pointers.\n"); + + int rowbytes = png_get_rowbytes(png_ptr, info_ptr); + + for (int i = 0; i < image->height; i++) + row_pointers[i] = (png_bytep)(image->pixels + (i * rowbytes)); + + if (setjmp(png_jmpbuf(png_ptr))) + FATAL_ERROR("Error writing \"%s\".\n", path); + + png_write_image(png_ptr, row_pointers); + + if (setjmp(png_jmpbuf(png_ptr))) + FATAL_ERROR("Error ending write of \"%s\".\n", path); + + png_write_end(png_ptr, NULL); + + fclose(fp); + + png_destroy_write_struct(&png_ptr, &info_ptr); + free(row_pointers); +} |