added 3dengfx into the repo, probably not the correct version for this

[summerhack] / src / 3dengfx / src / gfx / image_png.c

diff --git a/src/3dengfx/src/gfx/image_png.c b/src/3dengfx/src/gfx/image_png.c
new file mode 100644 (file)
index 0000000..1b0f759
--- /dev/null
+++ b/src/3dengfx/src/gfx/image_png.c
@@ -0,0 +1,124 @@
+/*
+Copyright 2004 John Tsiombikas <nuclear@siggraph.org>
+
+This is a small image library.
+
+This library 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 2 of the License, or
+(at your option) any later version.
+
+This library 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 library; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+/* png support
+ * 
+ * author: John Tsiombikas 2003
+ * modified: John Tsiombikas 2004
+ */
+
+#include "3dengfx_config.h"
+#include "image.h"
+#include <stdio.h>
+#include <string.h>
+
+#ifdef IMGLIB_USE_PNG
+
+#include <stdlib.h>
+#include <png.h>
+#include "color_bits.h"
+#include "common/types.h"
+
+#define FILE_SIG_BYTES 8
+
+int check_png(FILE *fp) {
+       unsigned char sig[FILE_SIG_BYTES];
+
+       fread(sig, 1, FILE_SIG_BYTES, fp);
+
+       return png_sig_cmp(sig, 0, FILE_SIG_BYTES) == 0 ? 1 : 0;
+}
+
+void *load_png(FILE *fp, unsigned long *xsz, unsigned long *ysz) {
+       png_struct *png_ptr;
+       png_info *info_ptr;
+       int i;
+       uint32_t **lineptr, *pixels;
+       int channel_bits, color_type, ilace_type, compression, filtering;
+       
+       if(!(png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0))) {
+               fclose(fp);
+               return 0;
+       }
+       
+       if(!(info_ptr = png_create_info_struct(png_ptr))) {
+               png_destroy_read_struct(&png_ptr, 0, 0);
+               fclose(fp);
+               return 0;
+       }
+       
+       if(setjmp(png_jmpbuf(png_ptr))) {               
+               png_destroy_read_struct(&png_ptr, &info_ptr, 0);
+               fclose(fp);
+               return 0;
+       }
+       
+       png_init_io(png_ptr, fp);       
+       png_set_sig_bytes(png_ptr, FILE_SIG_BYTES);
+       
+       png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_BGR, 0);
+               
+       png_get_IHDR(png_ptr, info_ptr, xsz, ysz, &channel_bits, &color_type, &ilace_type, &compression, &filtering);
+       pixels = malloc(*xsz * *ysz * sizeof(uint32_t));
+       
+       lineptr = (uint32_t**)png_get_rows(png_ptr, info_ptr);
+       
+       for(i=0; i<*ysz; i++) {
+               
+               switch(color_type) {
+               case PNG_COLOR_TYPE_RGB:
+                       {
+                               int j;
+                               unsigned char *ptr = (unsigned char*)lineptr[i];
+                               for(j=0; j<*xsz; j++) {
+                       
+                                       uint32_t pixel;
+                                       pixel = PACK_COLOR24(*(ptr+2), *(ptr+1), *ptr);
+                                       ptr+=3;
+                                       pixels[i * *xsz + j] = pixel;                   
+                               }
+                       }
+                       break;
+                       
+               case PNG_COLOR_TYPE_RGB_ALPHA:
+                       memcpy(&pixels[i * *xsz], lineptr[i], *xsz * sizeof(uint32_t));
+                       break;
+                       
+               default:
+                       png_destroy_read_struct(&png_ptr, &info_ptr, 0);
+                       fclose(fp);
+                       return 0;
+               }
+                               
+       }
+       
+       png_destroy_read_struct(&png_ptr, &info_ptr, 0);
+       fclose(fp);
+       
+       return pixels;
+}
+
+/* TODO: implement this */
+int save_png(FILE *fp, void *pixels, unsigned long xsz, unsigned long ysz) {
+       fprintf(stderr, "saving png files is not implemented yet");
+       return -1;
+}
+
+#endif /* IMGLIB_USE_PNG */