From: Nick Bowler Date: Tue, 11 Jun 2013 22:29:07 +0000 (-0400) Subject: lbximg: Add a new PNG writing routine. X-Git-Url: http://git.draconx.ca/gitweb/liblbx.git/commitdiff_plain/4d1c91362ed7719a1371ad977afd95f79821974f lbximg: Add a new PNG writing routine. This splits out the PNG output from the rest of the lbximg processing, so that it will be easier to add additional output formats (in par- ticular, it would be nice to have some sort of text-based format to facilitate automated testing). Take this opportunity to vastly improve the error handling. --- diff --git a/Makefile.am b/Makefile.am index 55fa7e3..8cfec29 100644 --- a/Makefile.am +++ b/Makefile.am @@ -37,7 +37,7 @@ lbxtool_SOURCES = src/lbxtool.c src/tools.c lbxtool_LDADD = liblbx.la libgnu.la $(lbxtool_OBJECTS): $(gnulib_headers) -lbximg_SOURCES = src/lbximg.c src/tools.c +lbximg_SOURCES = src/lbximg.c src/tools.c src/png.c lbximg_LDADD = liblbx.la libgnu.la $(LIBPNG_LIBS) $(lbximg_OBJECTS): $(gnulib_headers) diff --git a/configure.ac b/configure.ac index 2a3ddca..9ba3d42 100644 --- a/configure.ac +++ b/configure.ac @@ -33,10 +33,10 @@ AC_ARG_ENABLE([lbximg], have_libpng=no if test x"$enable_lbximg" = x"auto"; then -DX_CHECK_LIBPNG([1.2], [have_libpng=yes], [have_libpng=no]) +DX_CHECK_LIBPNG([1.5], [have_libpng=yes], [have_libpng=no]) fi if test x"$enable_lbximg" = x"yes"; then -DX_CHECK_LIBPNG([1.2], [have_libpng=yes]) +DX_CHECK_LIBPNG([1.5], [have_libpng=yes]) fi AM_CONDITIONAL([BUILD_LBXIMG], [test x"$have_libpng" = x"yes"]) diff --git a/src/imgoutput.h b/src/imgoutput.h new file mode 100644 index 0000000..46d9c9a --- /dev/null +++ b/src/imgoutput.h @@ -0,0 +1,9 @@ +#ifndef IMGOUTPUT_H_ +#define IMGOUTPUT_H_ + +int img_output_png(FILE *f, const char *filename, + unsigned width, unsigned height, + unsigned char **framedata, unsigned char **mask, + struct lbx_colour *palette); + +#endif diff --git a/src/lbximg.c b/src/lbximg.c index ff38c89..c761c17 100644 --- a/src/lbximg.c +++ b/src/lbximg.c @@ -25,13 +25,13 @@ #include #include -#include - #include "tools.h" #include "image.h" #include "error.h" #include "lbx.h" +#include "imgoutput.h" + /* Global flags */ static int verbose = 0; static char *outname = "out"; @@ -104,127 +104,39 @@ int parserange(unsigned frames, char *str, unsigned char *bits) return 0; } -static int ismasked(unsigned char **mask, unsigned width, unsigned height) -{ - unsigned y, x; - for (y = 0; y < height; y++) { - for (x = 0; x < width; x++) { - if (mask[y][x] == 0) return 1; - } - } - - return 0; -} - int outpng(unsigned int frameno, unsigned char **framedata, unsigned char **mask, unsigned int width, unsigned int height, struct lbx_colour palette[static 256]) { char name[strlen(outname) + sizeof ".65535.png"]; - unsigned char *row; - unsigned int x, y; FILE *of; - - png_structp png; - png_infop info; + int rc; assert(frameno < 65536); snprintf(name, sizeof name, "%s.%03d.png", outname, frameno); - row = malloc(4 * width); - if (!row) { - tool_err(0, "failed to allocate row buffer"); - return -1; - } - of = fopen(name, "wb"); if (!of) { tool_err(0, "failed to open %s", name); return -1; } - png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); - if (!png) { - tool_err(-1, "failed to init libpng."); - goto err; - } - - info = png_create_info_struct(png); - if (!info) { - tool_err(-1, "failed to init libpng."); - png_destroy_write_struct(&png, NULL); - goto err; + rc = img_output_png(of, name, width, height, framedata, mask, palette); + if (rc < 0) { + fclose(of); + return -1; } - if (setjmp(png_jmpbuf(png))) { - png_destroy_write_struct(&png, &info); - goto err; + if (fclose(of) == EOF) { + tool_err(0, "error writing %s", name); + return -1; } - - png_init_io(png, of); - - if (!ismasked(mask, width, height)) { - /* - * This case is easy; we can just feed the palette and pixel - * data to libpng and let it do its magic. - */ - - png_color png_palette[256]; - for (unsigned i = 0; i < 256; i++) { - png_palette[i].red = palette[i].red; - png_palette[i].green = palette[i].green; - png_palette[i].blue = palette[i].blue; - } - - png_set_IHDR(png, info, width, height, 8, - PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, - PNG_COMPRESSION_TYPE_DEFAULT, - PNG_FILTER_TYPE_DEFAULT); - png_set_PLTE(png, info, png_palette, 256); - png_set_rows(png, info, framedata); - png_write_png(png, info, PNG_TRANSFORM_IDENTITY, NULL); - } else { - /* - * Unfortunately, LBX doesn't translate nicely to PNG here. - * LBX has a 256 colour palette _plus_ transparency. - * We'll form an RGBA PNG to deal with this. - */ - - png_set_IHDR(png, info, width, height, 8, - PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, - PNG_COMPRESSION_TYPE_DEFAULT, - PNG_FILTER_TYPE_DEFAULT); - - png_write_info(png, info); - - for (y = 0; y < height; y++) { - for (x = 0; x < width; x++) { - row[4*x+0] = palette[framedata[y][x]].red; - row[4*x+1] = palette[framedata[y][x]].green; - row[4*x+2] = palette[framedata[y][x]].blue; - row[4*x+3] = (mask[y][x]) ? -1 : 0; - } - - png_write_row(png, row); - } - - png_write_end(png, NULL); - } - - png_destroy_write_struct(&png, &info); - fclose(of); - free(row); - if (verbose) printf("wrote %s\n", name); + return 0; -err: - fclose(of); - remove(name); - free(row); - return -1; } static int loadoverride(FILE *f, struct lbx_colour palette[static 256]) diff --git a/src/png.c b/src/png.c new file mode 100644 index 0000000..ee5d0a5 --- /dev/null +++ b/src/png.c @@ -0,0 +1,210 @@ +/* + * 2ooM: The Master of Orion II Reverse Engineering Project + * PNG output routines for lbximg extration. + * Copyright © 2013 Nick Bowler + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include +#include +#include +#include +#include + +#include + +#include "image.h" +#include "tools.h" + +#include "imgoutput.h" + +struct file_info { + const char *filename; + FILE *f; +}; + +static int is_masked(unsigned char **mask, unsigned width, unsigned height) +{ + for (unsigned y = 0; y < height; y++) { + for (unsigned x = 0; x < width; x++) { + if (mask[y][x] == 0) + return 1; + } + } + + return 0; +} + +static void fatal(png_structp png, int err, const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + tool_verr(err, fmt, ap); + va_end(ap); + + png_longjmp(png, 1); +} + +static void warning_fn(png_structp png, const char *msg) +{ + tool_err(-1, "libpng warning: %s", msg); +} + +static void error_fn(png_structp png, const char *msg) +{ + fatal(png, -1, "libpng error: %s", msg); +} + +/* + * We implement our own I/O routines because libpng's internal stdio calls do + * not handle errors particularly well. + */ +static void write_data(png_structp png, png_bytep data, png_size_t len) +{ + struct file_info *file = png_get_io_ptr(png); + size_t ret; + + ret = fwrite(data, 1, len, file->f); + if (ret < len) { + fatal(png, 0, "error writing %s", file->filename); + } +} + +static void flush_data(png_structp png) +{ + struct file_info *file = png_get_io_ptr(png); + + if (fflush(file->f) == EOF) { + fatal(png, 0, "error writing %s", file->filename); + } +} + +static void +write_rgba_frame(png_structp png, png_infop info, + unsigned char **framedata, unsigned char **mask, + struct lbx_colour *palette) +{ + png_uint_32 width = png_get_image_width(png, info); + png_uint_32 height = png_get_image_height(png, info); + unsigned char (*row)[4]; + jmp_buf parent; + + if (width >= PNG_UINT_32_MAX / sizeof *row) + fatal(png, -1, "image too wide to allocate row buffer"); + + row = png_malloc(png, width * sizeof *row); + + /* + * We need to establish our own error handler to free the row buffer. + * Some care must be taken to save/restore the caller's handler. + */ + memcpy(&parent, &png_jmpbuf(png), sizeof parent); + if (setjmp(png_jmpbuf(png))) { + png_free(png, row); + + memcpy(&png_jmpbuf(png), &parent, sizeof parent); + png_longjmp(png, 1); + } + + png_write_info(png, info); + for (png_uint_32 y = 0; y < height; y++) { + for (png_uint_32 x = 0; x < width; x++) { + row[x][0] = palette[framedata[y][x]].red; + row[x][1] = palette[framedata[y][x]].green; + row[x][2] = palette[framedata[y][x]].blue; + row[x][3] = mask[y][x] ? -1 : 0; + } + png_write_row(png, (void *)row); + } + png_write_end(png, NULL); + + memcpy(&png_jmpbuf(png), &parent, sizeof parent); +} + +static void +write_index_frame(png_structp png, png_infop info, unsigned char **framedata, + struct lbx_colour *palette) +{ + png_color png_palette[256]; + + for (unsigned i = 0; i < 256; i++) { + png_palette[i] = (png_color) { + .red = palette[i].red, + .green = palette[i].green, + .blue = palette[i].blue, + }; + } + + png_set_PLTE(png, info, png_palette, 256); + png_set_rows(png, info, framedata); + png_write_png(png, info, PNG_TRANSFORM_IDENTITY, NULL); +} + +int img_output_png(FILE *f, const char *filename, + unsigned width, unsigned height, + unsigned char **framedata, unsigned char **mask, + struct lbx_colour *palette) +{ + struct file_info file = { filename, f }; + png_structp png; + png_infop info; + + png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); + if (!png) { + tool_err(-1, "failed to init libpng."); + return -1; + } + + info = png_create_info_struct(png); + if (!info) { + tool_err(-1, "failed to init libpng."); + png_destroy_write_struct(&png, NULL); + return -1; + } + + if (setjmp(png_jmpbuf(png))) { + png_destroy_write_struct(&png, &info); + return -1; + } + + png_set_error_fn(png, NULL, error_fn, warning_fn); + png_set_write_fn(png, &file, write_data, flush_data); + + if (is_masked(mask, width, height)) { + /* + * Indexed colour mode can only be used for images without + * transparency, since indexed PNG requires sacrificing one or + * more palette colours to indicate transparency, while LBX + * does not. So we use full-up RGBA in this case. + */ + png_set_IHDR(png, info, width, height, 8, + PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, + PNG_COMPRESSION_TYPE_DEFAULT, + PNG_FILTER_TYPE_DEFAULT); + + write_rgba_frame(png, info, framedata, mask, palette); + } else { + png_set_IHDR(png, info, width, height, 8, + PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, + PNG_COMPRESSION_TYPE_DEFAULT, + PNG_FILTER_TYPE_DEFAULT); + + write_index_frame(png, info, framedata, palette); + } + + png_destroy_write_struct(&png, &info); + return 0; +}