implemented the forward energy improvement

main.c

@@ -68,6 +68,7 @@ void image_destruct(image_T* image) {
 void image_calculate_dist_buffer(image_T* image) {
     memset(image->dist_buffer, 0, image->width * sizeof(distance_T));
 
+    uint32_t*   mask_row        = &image->mask_buffer[image->width];
     uint32_t*   last_row        = image->buffer;
     uint32_t*   pixel_row       = &last_row[image->width];
     distance_T* dist_last_row   = image->dist_buffer;
@@ -75,22 +76,57 @@ void image_calculate_dist_buffer(image_T* image) {
 
     for (int y = 1; y < image->new_height; y++) {
         for (int x = 0; x < image->new_width; x++) {
-            uint32_t pixel = pixel_row[x];
+//            uint32_t pixel = pixel_row[x];
+//
+//            distance_T shortest_dist;
+//            bool       found_dist    = false;
+//            for (int i = (x > 0 ? -1 : 0); i < (x < image->new_width-1 ? 2 : 1); i++) {
+//                int32_t dist  = 0;
+//                dist         += pixel_distance(pixel, last_row[x + i], image->mask_buffer[(y * image->width) + x + i]);
+//                dist         += dist_last_row[x + i].distance;
+//
+//                if (!found_dist || shortest_dist.distance > dist) {
+//                    shortest_dist = (distance_T){dist, (int8_t)i};
+//                    found_dist    = true;
+//                }
+//            }
 
+
+            int32_t    dist;
             distance_T shortest_dist;
-            bool       found_dist    = false;
-            for (int i = (x > 0 ? -1 : 0); i < (x < image->new_width-1 ? 2 : 1); i++) {
-                int32_t dist = pixel_distance(pixel, last_row[x + i], image->mask_buffer[(y * image->width) + x + i]) + dist_last_row[x + i].distance;
 
-                if (!found_dist || shortest_dist.distance > dist) {
-                    shortest_dist = (distance_T){dist, (int8_t)i};
-                    found_dist    = true;
+            if (x > 0) {
+                dist  = 0;
+                dist += dist_last_row[x - 1].distance;
+                dist += pixel_distance(pixel_row[x - 1], pixel_row[x + 1], mask_row[x]);
+                dist += pixel_distance(last_row [x],     pixel_row[x - 1], mask_row[x]);
+
+                shortest_dist = (distance_T) {dist, -1};
+            }
+
+            dist  = -10;
+            dist += dist_last_row[x].distance;
+            dist += pixel_distance(pixel_row[x - 1], pixel_row[x + 1], mask_row[x]);
+
+            if (x == 0 || shortest_dist.distance > dist) {
+                shortest_dist = (distance_T) {dist, 0};
+            }
+
+            if (x < image->new_width-1) {
+                dist  = 0;
+                dist += dist_last_row[x + 1].distance;
+                dist += pixel_distance(pixel_row[x - 1], pixel_row[x + 1], mask_row[x]);
+                dist += pixel_distance(last_row [x],     pixel_row[x + 1], mask_row[x]);
+
+                if (shortest_dist.distance > dist) {
+                    shortest_dist = (distance_T) {dist, 1};
                 }
             }
 
             dist_pixel_row[x] = shortest_dist;
         }
 
+        mask_row       = &mask_row[image->width];
         last_row       = pixel_row;
         pixel_row      = &pixel_row[image->width];
         dist_last_row  = dist_pixel_row;
@@ -118,7 +154,7 @@ uint32_t image_find_best_line(image_T* image) {
 void image_cut_line(image_T* image, uint32_t line_id) {
     uint32_t x = line_id;
 
-    for (uint32_t y = image->height-1; y > 0; y--) {
+    for (uint32_t y = image->new_height-1; y > 0; y--) {
         distance_T dist = image->dist_buffer[(image->width * y) + x];
         x += dist.direction;
         memcpy(&image->buffer[(image->width * y) + x], &image->buffer[(image->width * y) + x + 1], (image->new_width - x) * sizeof(uint32_t));
@@ -156,7 +192,7 @@ void image_dump(image_T* image) {
 int main(int argc, char* argv[]) {
     printf("Line Cutter - Juniorcamp Informatik\n");
 
-    image_T* image = image_load("../bench.png", "../bench_mask.png");
+    image_T* image = image_load("../paris.png", "../paris_mask.png");
 
     gfx_open(800, 600, "Juniorcamp Informatik - Line Cutter");
     image_dump(image);
@@ -167,8 +203,10 @@ int main(int argc, char* argv[]) {
         image_dump(image);
         switch (c) {
             case 's': {
-                image_calculate_dist_buffer(image);
-                image_cut_line(image, image_find_best_line(image));
+                if (image->new_width > 0) {
+                    image_calculate_dist_buffer(image);
+                    image_cut_line(image, image_find_best_line(image));
+                }
                 break;
             }
             case 'q': {