WIP old converter port, gives funky results

img2cpi.c

@@ -84,7 +84,8 @@ struct image *image_load(const char *fp);
 struct image *image_new(int w, int h);
 struct image *image_resize(struct image *original, int new_w, int new_h);
 struct image_pal *image_quantize(struct image *original, const union color *colors, size_t n_colors);
-int get_color_difference(union color a, union color b);
+float get_color_difference(union color a, union color b);
+float get_color_brightness(union color clr);
 void image_unload(struct image *img);
 void get_size_keep_aspect(int w, int h, int dw, int dh, int *ow, int *oh);
 
@@ -251,6 +252,53 @@ int main(int argc, char **argv) {
     // use old 2x3
     for (int y = 0; y < args.height; y++) {
       for (int x = 0; x < args.width; x++) {
+        unsigned char darkest_i = 0, brightest_i = 0;
+        float darkest_diff = 0xffffff, brightest_diff = 0;
+
+        for (int oy = 0; oy < 3; oy++) {
+          for (int ox = 0; ox < 2; ox++) {
+            unsigned char pix = quantized_image->pixels[ox + (x + (y * 3 + oy)) * 2];
+            float brightness = get_color_brightness(palette[pix]);
+            if (brightness >= brightest_diff) {
+              brightest_i = pix;
+              brightest_diff = brightness;
+            }
+            if (brightness <= darkest_diff) {
+              darkest_i = pix;
+              darkest_diff = brightness;
+            }
+          }
+        }
+
+        unsigned char bitmap = 0;
+        const static unsigned char pixel_bits[3][2] = { { 1, 2}, { 4, 8 }, { 16, 0 } };
+        for (int oy = 0; oy < 3; oy++) {
+          for (int ox = 0; ox < 2; ox++) {
+            if (ox == 1 && oy == 2) continue;
+            unsigned char pix = quantized_image->pixels[ox + (x + (y * 3 + oy)) * 2];
+            float diff_bg = get_color_difference(palette[darkest_i], palette[pix]);
+            float diff_fg = get_color_difference(palette[brightest_i], palette[pix]);
+            if (diff_fg < diff_bg) {
+              bitmap |= pixel_bits[oy][ox];
+            }
+          }
+        }
+
+        {
+          unsigned char pix = quantized_image->pixels[1 + (x + (y * 3 + 2)) * 2];
+          float diff_bg = get_color_difference(palette[darkest_i], palette[pix]);
+          float diff_fg = get_color_difference(palette[brightest_i], palette[pix]);
+          if (diff_fg > diff_bg) {
+            bitmap ^= 31;
+            unsigned char tmp = darkest_i;
+            darkest_i = brightest_i;
+            brightest_i = tmp;
+          }
+        }
+
+        characters[x + y * args.width].character = 0x80 + bitmap;
+        characters[x + y * args.width].bg = darkest_i;
+        characters[x + y * args.width].fg = brightest_i;
       }
     }
   } else {
@@ -258,7 +306,7 @@ int main(int argc, char **argv) {
     for (int y = 0; y < args.height; y++) {
       for (int x = 0; x < args.width; x++) {
         // Oh boy...
-        int min_diff = 0xffffff;
+        float min_diff = 0xffffff;
         char closest_sym = 0x00, closest_color = 0xae;
         for (int sym = 0x01; sym <= 0xFF; sym++) {
           if (sym == '\t' || sym == '\n' || sym == '\r' || sym == '\x0e') {
@@ -267,7 +315,7 @@ int main(int argc, char **argv) {
           for (int color = 0x00; color <= 0xff; color++) {
             union color cell_bg = palette[color & 0xF],
                         cell_fg = palette[color >> 4];
-            int difference = 0;
+            float difference = 0;
             for (int oy = 0; oy < 11; oy++) {
               unsigned char sym_line = font_atlas[sym][oy];
               for (int ox = 0; ox < 8; ox++) {
@@ -590,13 +638,17 @@ struct image_pal *image_quantize(struct image *original, const union color *colo
   return out;
 }
 
-int get_color_difference(union color a, union color b) {
+float get_color_difference(union color a, union color b) {
   int dr = a.rgba.r - b.rgba.r,
       dg = a.rgba.g - b.rgba.g,
       db = a.rgba.b - b.rgba.b;
   return dr * dr + dg * dg + db * db;
 }
 
+float get_color_brightness(union color clr) {
+  return get_color_difference(clr, (union color){ .v = 0 });
+}
+
 const union color DEFAULT_PALETTE[16] = {
   { 0xf0, 0xf0, 0xf0, 0xff },
   { 0xf2, 0xb2, 0x33, 0xff },