# png.cpp

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    00001 /* $Id: png.cpp 18809 2010-01-15 16:41:15Z rubidium $ */
    00002
    00003 /*
    00004  * This file is part of OpenTTD.
    00005  * OpenTTD 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, version 2.
    00006  * OpenTTD 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.
    00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
    00008  */
    00009
    00012 #ifdef WITH_PNG
    00013
    00014 #include "../stdafx.h"
    00015 #include "../fileio_func.h"
    00016 #include "../debug.h"
    00017 #include "png.hpp"
    00018 #include <png.h>
    00019
    00020 #define PNG_SLOT 62
    00021
    00022 static void PNGAPI png_my_read(png_structp png_ptr, png_bytep data, png_size_t length)
    00023 {
    00024   FioReadBlock(data, length);
    00025 }
    00026
    00027 static void PNGAPI png_my_error(png_structp png_ptr, png_const_charp message)
    00028 {
    00029   DEBUG(sprite, 0, "ERROR (libpng): %s - %s", message, (char *)png_get_error_ptr(png_ptr));
    00030   longjmp(png_jmpbuf(png_ptr), 1);
    00031 }
    00032
    00033 static void PNGAPI png_my_warning(png_structp png_ptr, png_const_charp message)
    00034 {
    00035   DEBUG(sprite, 0, "WARNING (libpng): %s - %s", message, (char *)png_get_error_ptr(png_ptr));
    00036 }
    00037
    00038 static bool OpenPNGFile(const char *filename, uint32 id, bool mask)
    00039 {
    00040   char png_file[MAX_PATH];
    00041
    00042   snprintf(png_file, sizeof(png_file), "sprites" PATHSEP "%s" PATHSEP "%d%s.png", filename, id, mask ? "m" : "");
    00043   if (FioCheckFileExists(png_file)) {
    00044     FioOpenFile(PNG_SLOT, png_file);
    00045     return true;
    00046   }
    00047
    00048   /* TODO -- Add TAR support */
    00049   return false;
    00050 }
    00051
    00052 static bool LoadPNG(SpriteLoader::Sprite *sprite, const char *filename, uint32 id, volatile bool mask)
    00053 {
    00054   png_byte header[8];
    00055   png_structp png_ptr;
    00056   png_infop info_ptr, end_info;
    00057   uint bit_depth, colour_type;
    00058   uint i, pixelsize;
    00059   SpriteLoader::CommonPixel *dst;
    00060
    00061   if (!OpenPNGFile(filename, id, mask)) return mask; // If mask is true, and file not found, continue true anyway, as it isn't a show-stopper
    00062
    00063   /* Check the header */
    00064   FioReadBlock(header, 8);
    00065   if (png_sig_cmp(header, 0, 8) != 0) return false;
    00066
    00067   /* Create the reader */
    00068   png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, png_my_error, png_my_warning);
    00069   if (png_ptr == NULL) return false;
    00070
    00071   /* Create initial stuff */
    00072   info_ptr = png_create_info_struct(png_ptr);
    00073   if (info_ptr == NULL) {
    00074     png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
    00075     return false;
    00076   }
    00077   end_info = png_create_info_struct(png_ptr);
    00078   if (end_info == NULL) {
    00079     png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
    00080     return false;
    00081   }
    00082
    00083   /* Make sure that upon error, we can clean up graceful */
    00084   if (setjmp(png_jmpbuf(png_ptr))) {
    00085     png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
    00086     return false;
    00087   }
    00088
    00089   /* Read the file */
    00090   png_set_read_fn(png_ptr, NULL, png_my_read);
    00091   png_set_sig_bytes(png_ptr, 8);
    00092
    00093   png_read_info(png_ptr, info_ptr);
    00094
    00095   if (!mask) {
    00096     /* Read the text chunks */
    00097     png_textp text_ptr;
    00098     int num_text = 0;
    00099     png_get_text(png_ptr, info_ptr, &text_ptr, &num_text);
    00100     if (num_text == 0) DEBUG(misc, 0, "Warning: PNG Sprite '%s/%d.png' doesn't have x_offs and y_offs; expect graphical problems", filename, id);
    00101     for (int i = 0; i < num_text; i++) {
    00102       /* x_offs and y_offs are in the text-chunk of PNG */
    00103       if (strcmp("x_offs", text_ptr[i].key) == 0) sprite->x_offs = strtol(text_ptr[i].text, NULL, 0);
    00104       if (strcmp("y_offs", text_ptr[i].key) == 0) sprite->y_offs = strtol(text_ptr[i].text, NULL, 0);
    00105     }
    00106
    00107     sprite->height = png_get_image_height(png_ptr, info_ptr);
    00108     sprite->width  = png_get_image_width(png_ptr, info_ptr);
    00109     sprite->AllocateData(sprite->width * sprite->height);
    00110   }
    00111
    00112   bit_depth  = png_get_bit_depth(png_ptr, info_ptr);
    00113   colour_type = png_get_color_type(png_ptr, info_ptr);
    00114
    00115   if (mask && (bit_depth != 8 || colour_type != PNG_COLOR_TYPE_PALETTE)) {
    00116     DEBUG(misc, 0, "Ignoring mask for SpriteID %d as it isn't a 8 bit palette image", id);
    00117     return true;
    00118   }
    00119
    00120   if (!mask) {
    00121     if (bit_depth == 16) png_set_strip_16(png_ptr);
    00122
    00123     if (colour_type == PNG_COLOR_TYPE_PALETTE) {
    00124       png_set_palette_to_rgb(png_ptr);
    00125       colour_type = PNG_COLOR_TYPE_RGB;
    00126     }
    00127     if (colour_type == PNG_COLOR_TYPE_GRAY || colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
    00128       png_set_gray_to_rgb(png_ptr);
    00129       colour_type = PNG_COLOR_TYPE_RGB;
    00130     }
    00131
    00132     if (colour_type == PNG_COLOR_TYPE_RGB) {
    00133       png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
    00134     }
    00135
    00136     pixelsize = sizeof(uint32);
    00137   } else {
    00138     pixelsize = sizeof(uint8);
    00139   }
    00140
    00141   png_bytep row_pointer = AllocaM(png_byte, png_get_image_width(png_ptr, info_ptr) * pixelsize);
    00142
    00143   for (i = 0; i < png_get_image_height(png_ptr, info_ptr); i++) {
    00144     png_read_row(png_ptr, row_pointer, NULL);
    00145
    00146     dst = sprite->data + i * png_get_image_width(png_ptr, info_ptr);
    00147
    00148     for (uint x = 0; x < png_get_image_width(png_ptr, info_ptr); x++) {
    00149       if (mask) {
    00150         if (row_pointer[x * sizeof(uint8)] != 0) {
    00151           dst[x].r = 0;
    00152           dst[x].g = 0;
    00153           dst[x].b = 0;
    00154           /* Alpha channel is used from the original image (to allow transparency in remap colours) */
    00155           dst[x].m = row_pointer[x * sizeof(uint8)];
    00156         }
    00157       } else {
    00158         dst[x].r = row_pointer[x * sizeof(uint32) + 0];
    00159         dst[x].g = row_pointer[x * sizeof(uint32) + 1];
    00160         dst[x].b = row_pointer[x * sizeof(uint32) + 2];
    00161         dst[x].a = row_pointer[x * sizeof(uint32) + 3];
    00162         dst[x].m = 0;
    00163       }
    00164     }
    00165   }
    00166
    00167   png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
    00168
    00169   return true;
    00170 }
    00171
    00172 bool SpriteLoaderPNG::LoadSprite(SpriteLoader::Sprite *sprite, uint8 file_slot, size_t file_pos, SpriteType sprite_type)
    00173 {
    00174   const char *filename = FioGetFilename(file_slot);
    00175   if (!LoadPNG(sprite, filename, (uint32)file_pos, false)) return false;
    00176   if (!LoadPNG(sprite, filename, (uint32)file_pos, true)) return false;
    00177   return true;
    00178 }
    00179
    00180 #endif /* WITH_PNG */