+#include <stdio.h>
+#include <string.h>
+#include <png.h>
+#include "readpng.h"
+
+void readpng(void *dest, const char *fname, readpng_what what)
+{
+ FILE *fp;
+ png_structp png_ptr = NULL;
+ png_infop info_ptr = NULL;
+ png_bytepp row_ptr = NULL;
+
+ if (dest == NULL || fname == NULL)
+ {
+ return;
+ }
+
+ fp = fopen(fname, "rb");
+ if (fp == NULL)
+ {
+ printf(__FILE__ ": failed to open: %s\n", fname);
+ return;
+ }
+
+ png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+ if (!png_ptr)
+ {
+ printf(__FILE__ ": png_create_read_struct() failed\n");
+ fclose(fp);
+ return;
+ }
+
+ info_ptr = png_create_info_struct(png_ptr);
+ if (!info_ptr)
+ {
+ printf(__FILE__ ": png_create_info_struct() failed\n");
+ goto done;
+ }
+
+ // Start reading
+ png_init_io(png_ptr, fp);
+ png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_STRIP_ALPHA | PNG_TRANSFORM_PACKING, NULL);
+ row_ptr = png_get_rows(png_ptr, info_ptr);
+ if (row_ptr == NULL)
+ {
+ printf(__FILE__ ": png_get_rows() failed\n");
+ goto done;
+ }
+
+ // printf("%s: %ix%i @ %ibpp\n", fname, (int)info_ptr->width, (int)info_ptr->height, info_ptr->pixel_depth);
+
+ switch (what)
+ {
+ case READPNG_BG:
+ {
+ int height, width, h;
+ unsigned short *dst = dest;
+ if (info_ptr->pixel_depth != 24)
+ {
+ printf(__FILE__ ": bg image uses %ibpp, needed 24bpp\n", info_ptr->pixel_depth);
+ break;
+ }
+ height = info_ptr->height;
+ if (height > 240) height = 240;
+ width = info_ptr->width;
+ if (width > 320) width = 320;
+
+ for (h = 0; h < height; h++)
+ {
+ unsigned char *src = row_ptr[h];
+ int len = width;
+ while (len--)
+ {
+ *dst++ = ((src[0]&0xf8)<<8) | ((src[1]&0xf8)<<3) | (src[2] >> 3);
+ src += 3;
+ }
+ dst += 320 - width;
+ }
+ break;
+ }
+
+ case READPNG_FONT:
+ {
+ int x, y, x1, y1;
+ unsigned char *dst = dest;
+ if (info_ptr->width != 128 || info_ptr->height != 160)
+ {
+ printf(__FILE__ ": unexpected font image size %ix%i, needed 128x160\n",
+ (int)info_ptr->width, (int)info_ptr->height);
+ break;
+ }
+ if (info_ptr->pixel_depth != 8)
+ {
+ printf(__FILE__ ": font image uses %ibpp, needed 8bpp\n", info_ptr->pixel_depth);
+ break;
+ }
+ for (y = 0; y < 16; y++)
+ {
+ for (x = 0; x < 16; x++)
+ {
+ for (y1 = 0; y1 < 10; y1++)
+ {
+ unsigned char *src = row_ptr[y*10 + y1] + x*8;
+ for (x1 = 8/2; x1 > 0; x1--, src+=2)
+ *dst++ = ((src[0]^0xff) & 0xf0) | ((src[1]^0xff) >> 4);
+ }
+ }
+ }
+ break;
+ }
+
+ case READPNG_SELECTOR:
+ {
+ int x1, y1;
+ unsigned char *dst = dest;
+ if (info_ptr->width != 8 || info_ptr->height != 10)
+ {
+ printf(__FILE__ ": unexpected selector image size %ix%i, needed 8x10\n",
+ (int)info_ptr->width, (int)info_ptr->height);
+ break;
+ }
+ if (info_ptr->pixel_depth != 8)
+ {
+ printf(__FILE__ ": selector image uses %ibpp, needed 8bpp\n", info_ptr->pixel_depth);
+ break;
+ }
+ for (y1 = 0; y1 < 10; y1++)
+ {
+ unsigned char *src = row_ptr[y1];
+ for (x1 = 8/2; x1 > 0; x1--, src+=2)
+ *dst++ = ((src[0]^0xff) & 0xf0) | ((src[1]^0xff) >> 4);
+ }
+ break;
+ }
+ }
+
+
+done:
+ png_destroy_read_struct(&png_ptr, info_ptr ? &info_ptr : NULL, (png_infopp)NULL);
+ fclose(fp);
+}
+
+