Initial seemingly working version.

1 files changed, 272 insertions, 3 deletions

diff --git a/png8.c b/png8.c
index 6022562..6db1769 100755
--- a/png8.c
+++ b/png8.c
@@ -41,7 +41,8 @@
 #define FALSE   (0)
 #endif
 
-#define IS_BLACK(ul)    (((ul) && 0x00FFFFFFul) == 0)
+#define COLOUR(ul)      ((ul) & 0x00FFFFFFul)
+#define IS_BLACK(ul)    (COLOUR(ul) == 0)
 #define IS_TRANS(ul)    (((ul) && 0xFF000000ul) == 0)
 
 
@@ -92,9 +93,15 @@ static void Help(void)
 "-1         - Produce a monochrome sprite data set (e.g. Spectrum).\n"
 "-4         - Produce a 4-colour sprite data set (e.g. Commodore 64).\n"
 "\nOptional switches:\n"
-"-s         - Treat black the same as a transparent pixel.\n"
+"-b         - Don't treat black the same as a transparent pixel.\n"
 "-p <text>  - Use <text> in place of 'byte' for output.\n"
-"-i         - For monochrome data, produce pre-shifted values.\n"
+"-s         - For monochrome data, produce pre-shifted values.\n"
+"-w <width> - Set the sprite width to <width>.  This must be a multiple of 8.\n"
+"-d         - Don't use double-width pixels in 4 colour mode.\n"
+"-c0        - Set colour 0 to RGB value RRGGBB, expressed as a hex number.\n"
+"-c1        - Set colour 1 to RGB value RRGGBB, expressed as a hex number.\n"
+"-c2        - Set colour 2 to RGB value RRGGBB, expressed as a hex number.\n"
+"-c3        - Set colour 3 to RGB value RRGGBB, expressed as a hex number.\n"
 "";
 
     fprintf(stderr,"%s\n", help);
@@ -116,6 +123,18 @@ static void Exit(const char *fmt, ...)
 }
 
 
+static void Warning(const char *fmt, ...)
+{
+    va_list va;
+
+    fprintf(stderr, "WARNING: ");
+
+    va_start(va, fmt);
+    vfprintf(stderr, fmt, va);
+    va_end(va);
+}
+
+
 static void *Malloc(size_t size)
 {
     void *p = malloc(size);
@@ -138,6 +157,84 @@ static ulong RGBA(png_byte r, png_byte g, png_byte b, png_byte a)
 }
 
 
+static void PrintSpriteData(const char *opcode,
+                            ulong sprite_data[],
+                            int max,
+                            int pre_shift)
+{
+    int f;
+
+    printf("\t%s ", opcode);
+
+    for(f = 0; f < max; f++)
+    {
+        if (f)
+        {
+            printf(",");
+        }
+
+        printf("%lu", sprite_data[f]);
+    }
+
+    if (pre_shift)
+    {
+        printf(",0");
+    }
+
+    printf("\n");
+}
+
+
+static void PrintSpriteDataShifted(const char *opcode,
+                                   ulong sprite_data[],
+                                   int max)
+{
+    int s;
+    int f;
+    ulong data[8][5] = {0};
+
+    for(s = 1; s < 8; s++)
+    {
+        for(f = 0; f <= max; f++)
+        {
+            if (f == max)
+            {
+                data[s][f] = (sprite_data[f-1] << (8 - s)) & 0xff;
+            }
+            else if (f)
+            {
+                data[s][f] =
+                    ((sprite_data[f] >> s) | (sprite_data[f-1] << (8 - s)))
+                        & 0xff;
+            }
+            else
+            {
+                data[s][f] = sprite_data[f] >> s;
+            }
+        }
+    }
+
+    max++;
+
+    for(s = 1; s < 8; s++)
+    {
+        printf("\t%s ", opcode);
+
+        for(f = 0; f < max; f++)
+        {
+            if (f)
+            {
+                printf(",");
+            }
+
+            printf("%lu", data[s][f]);
+        }
+
+        printf("\n");
+    }
+}
+
+
 /* ---------------------------------------- MAIN
 */
 int main(int argc, char *argv[])
@@ -151,6 +248,11 @@ int main(int argc, char *argv[])
     const char *opcode = "byte";
     output_type_t output = OUTPUT_Undefined;
     int pre_shift = FALSE;
+    int use_black = TRUE;
+    int sprite_width = 8;
+    int pix_per_byte = 8;
+    int step = 1;
+    ulong col[4] = {0, 0xff0000ul, 0x00ff00ul, 0x0000fful};
     int f;
     FILE *fp;
     char header[8];
@@ -171,6 +273,74 @@ int main(int argc, char *argv[])
 
             case '4':
                 output = OUTPUT_4Col;
+                sprite_width = 24;
+                step = 2;
+                pix_per_byte = 4;
+                pre_shift = FALSE;
+                break;
+
+            case 'b':
+                use_black = FALSE;
+                break;
+
+            case 's':
+                if (output != OUTPUT_4Col)
+                {
+                    pre_shift = TRUE;
+                }
+                break;
+
+            case 'd':
+                step = 1;
+                break;
+
+            case 'c':
+            {
+                int c = argv[f][2] - '0';
+
+                if (argv[++f] && c >= 0 && c <= 3)
+                {
+                    col[c] = strtoul(argv[f], NULL, 16);
+                }
+                else
+                {
+                    Usage();
+                }
+
+                break;
+            }
+
+            case 'p':
+                if (argv[++f])
+                {
+                    opcode = argv[f];
+                }
+                else
+                {
+                    Usage();
+                }
+                break;
+
+            case 'w':
+                if (argv[++f])
+                {
+                    sprite_width = atoi(argv[f]);
+
+                    if (sprite_width % 8)
+                    {
+                        Exit("Sprite width must be a multiple of 8.\n");
+                    }
+
+                    if (sprite_width < 8 || sprite_width > 32)
+                    {
+                        Exit("Sprite width mustn't be greater than "
+                                "32 or less than 8.\n");
+                    }
+                }
+                else
+                {
+                    Usage();
+                }
                 break;
 
             default:
@@ -224,6 +394,22 @@ int main(int argc, char *argv[])
     colour_depth = png_get_bit_depth(png, png_info);
     num_passes = png_set_interlace_handling(png);
 
+    if (width < sprite_width * step)
+    {
+        Exit("Width %d less than sprite width %d\n", width,
+                                                     sprite_width * step);
+    }
+
+    if (width % (sprite_width * step))
+    {
+        Warning("Width not a multiple of %d.\n", sprite_width * step);
+    }
+
+    if (sprite_width > 16 && output == OUTPUT_4Col)
+    {
+        Exit("Width must be 16 or less in 4-colour mode.\n");
+    }
+
     if (colour_type != PNG_COLOR_TYPE_RGBA)
     {
         Exit("PNG must be an RGB image with an alpha channel.\n");
@@ -247,6 +433,89 @@ int main(int argc, char *argv[])
 
     fclose(fp);
 
+    for(f = 0; f < width/(sprite_width*step); f++)
+    {
+        int x,y;
+        int bx;
+
+        printf("sprite_%d:\n", f);
+
+        bx = sprite_width * step * f * 4;
+
+        for(y = 0; y < height; y++)
+        {
+            ulong sprite_data[4] = {0};
+            int i = 0;
+
+            for(x = 0; x < sprite_width; x++)
+            {
+                ulong pcol = RGBA(data[y][bx + x * 4 * step + 0],
+                                  data[y][bx + x * 4 * step + 1],
+                                  data[y][bx + x * 4 * step + 2],
+                                  data[y][bx + x * 4 * step + 3]);
+
+                if ((x) && (x % pix_per_byte) == 0)
+                {
+                    i++;
+                }
+
+                switch(output)
+                {
+                    case OUTPUT_Mono:
+                        if (IS_TRANS(pcol) || (use_black && IS_BLACK(pcol)))
+                        {
+                            sprite_data[i] <<= 1ul;
+                            sprite_data[i] |= 0;
+                        }
+                        else
+                        {
+                            sprite_data[i] <<= 1ul;
+                            sprite_data[i] |= 1;
+                        }
+                        break;
+
+                    case OUTPUT_4Col:
+                        if (COLOUR(pcol) == col[1])
+                        {
+                            sprite_data[i] <<= 2ul;
+                            sprite_data[i] |= 0x01;
+                        }
+                        else if (COLOUR(pcol) == col[2])
+                        {
+                            sprite_data[i] <<= 2ul;
+                            sprite_data[i] |= 0x02;
+                        }
+                        else if (COLOUR(pcol) == col[3])
+                        {
+                            sprite_data[i] <<= 2ul;
+                            sprite_data[i] |= 0x03;
+                        }
+                        else
+                        {
+                            sprite_data[i] <<= 2ul;
+                            sprite_data[i] |= 0;
+                        }
+                        break;
+
+                    default:
+                        break;
+                }
+            }
+
+            if ((x) && (x % pix_per_byte) == 0)
+            {
+                i++;
+            }
+
+            PrintSpriteData(opcode, sprite_data, i, pre_shift);
+
+            if (pre_shift)
+            {
+                PrintSpriteDataShifted(opcode, sprite_data, i);
+            }
+        }
+    }
+
     for(f = 0; f < height; f++)
     {
         free(data[f]);