X-Git-Url: https://git.artsoft.org/?p=rocksndiamonds.git;a=blobdiff_plain;f=src%2Fpcx.c;h=514d30de6041f7683a86e96cffed79e474767357;hp=f2dac1d9cfdb266bc669d54bab7a6a3770b4988b;hb=182260bf970d56e056a8c0c580ad61302d21ab0f;hpb=c56ae03b51200429cfa20db7d61cfe907dc2e26e diff --git a/src/pcx.c b/src/pcx.c index f2dac1d9..514d30de 100644 --- a/src/pcx.c +++ b/src/pcx.c @@ -11,6 +11,7 @@ * pcx.c * ***********************************************************/ +#include "pcx.h" #include "image.h" #include "misc.h" @@ -44,8 +45,76 @@ struct PCX_Header unsigned char filler[58]; /* fill to struct size of 128 */ }; -static byte *PCX_ReadBitmap(Image *, byte *, byte *); -static byte *PCX_ReadColormap(Image *, byte *, byte *); +static byte *PCX_ReadBitmap(Image *image, byte *buffer_ptr, byte *buffer_last) +{ + /* Run Length Encoding: If the two high bits are set, + * then the low 6 bits contain a repeat count, and the byte to + * repeat is the next byte in the file. If the two high bits are + * not set, then this is the byte to write. + */ + + unsigned int bytes_per_pixel = (image->depth + 7) / 8; + register byte *bitmap_ptr, *bitmap_last; + register byte value, count; + + bitmap_ptr = image->data; + bitmap_last = bitmap_ptr + (image->width * image->height * bytes_per_pixel); + + while (bitmap_ptr < bitmap_last && buffer_ptr < buffer_last) + { + value = *buffer_ptr++; + + if ((value & 0xc0) == 0xc0) /* this is a repeat count byte */ + { + count = value & 0x3f; /* extract repeat count from byte */ + value = *buffer_ptr++; /* next byte is value to repeat */ + + for (; count && bitmap_ptr < bitmap_last; count--) + *bitmap_ptr++ = value; + + if (count) /* repeat count spans end of bitmap */ + return NULL; + } + else + *bitmap_ptr++ = value; + + image->rgb.color_used[value] = TRUE; + } + + /* check if end of buffer was reached before end of bitmap */ + if (bitmap_ptr < bitmap_last) + return NULL; + + /* return current buffer position for next decoding function */ + return buffer_ptr; +} + +static byte *PCX_ReadColormap(Image *image,byte *buffer_ptr, byte *buffer_last) +{ + int i, magic; + + /* read colormap magic byte */ + magic = *buffer_ptr++; + + /* check magic colormap header byte */ + if (magic != PCX_256COLORS_MAGIC) + return NULL; + + /* check if enough bytes left for a complete colormap */ + if (buffer_ptr + PCX_COLORMAP_SIZE > buffer_last) + return NULL; + + /* read 256 colors from PCX colormap */ + for (i=0; irgb.red[i] = *buffer_ptr++ << 8; + image->rgb.green[i] = *buffer_ptr++ << 8; + image->rgb.blue[i] = *buffer_ptr++ << 8; + } + + /* return current buffer position for next decoding function */ + return buffer_ptr; +} Image *Read_PCX_to_Image(char *filename) { @@ -157,74 +226,3 @@ Image *Read_PCX_to_Image(char *filename) return image; } - -static byte *PCX_ReadBitmap(Image *image, byte *buffer_ptr, byte *buffer_last) -{ - /* Run Length Encoding: If the two high bits are set, - * then the low 6 bits contain a repeat count, and the byte to - * repeat is the next byte in the file. If the two high bits are - * not set, then this is the byte to write. - */ - - unsigned int bytes_per_pixel = (image->depth + 7) / 8; - register byte *bitmap_ptr, *bitmap_last; - register byte value, count; - - bitmap_ptr = image->data; - bitmap_last = bitmap_ptr + (image->width * image->height * bytes_per_pixel); - - while (bitmap_ptr < bitmap_last && buffer_ptr < buffer_last) - { - value = *buffer_ptr++; - - if ((value & 0xc0) == 0xc0) /* this is a repeat count byte */ - { - count = value & 0x3f; /* extract repeat count from byte */ - value = *buffer_ptr++; /* next byte is value to repeat */ - - for (; count && bitmap_ptr < bitmap_last; count--) - *bitmap_ptr++ = value; - - if (count) /* repeat count spans end of bitmap */ - return NULL; - } - else - *bitmap_ptr++ = value; - - image->rgb.color_used[value] = TRUE; - } - - /* check if end of buffer was reached before end of bitmap */ - if (bitmap_ptr < bitmap_last) - return NULL; - - /* return current buffer position for next decoding function */ - return buffer_ptr; -} - -static byte *PCX_ReadColormap(Image *image,byte *buffer_ptr, byte *buffer_last) -{ - int i, magic; - - /* read colormap magic byte */ - magic = *buffer_ptr++; - - /* check magic colormap header byte */ - if (magic != PCX_256COLORS_MAGIC) - return NULL; - - /* check if enough bytes left for a complete colormap */ - if (buffer_ptr + PCX_COLORMAP_SIZE > buffer_last) - return NULL; - - /* read 256 colors from PCX colormap */ - for (i=0; irgb.red[i] = *buffer_ptr++ << 8; - image->rgb.green[i] = *buffer_ptr++ << 8; - image->rgb.blue[i] = *buffer_ptr++ << 8; - } - - /* return current buffer position for next decoding function */ - return buffer_ptr; -}