add cluster support to gen-data.rb, show centroids on generated png

1 files changed, 13 insertions, 12 deletions

diff --git a/km-draw.c b/km-draw.c
index 7f59df3..ddf1b26 100644
--- a/km-draw.c
+++ b/km-draw.c
@@ -8,23 +8,24 @@ km_set_draw(
   uint8_t * const rgb,
   const size_t width,
   const size_t height,
+  const int dot_size,
   const uint32_t color
 ) {
   for (size_t i = 0; i < set->num_rows; i++) {
     const float *row = km_set_get_row(set, i);
-    const size_t x = (width - 1) * row[0],
-                 y = (height - 1) * row[1],
-                 ofs = 3 * (width * y + x);
 
-    if (x >= width || y >= height) {
-      die(
-        "km_set_draw(): point out of bounds (row: %zu, point: [%0.2f, %0.2f], pixel: %zux%zu, bounds: %zux%zu)",
-        i, row[0], row[1], x, y, width, height
-      );
+    for (int yo = 0; yo < dot_size; yo++) {
+      for (int xo = 0; xo < dot_size; xo++) {
+        const int x = (width - 1) * row[0] - dot_size / 2 + xo,
+                   y = (height - 1) * row[1] - dot_size / 2 + yo,
+                   ofs = 3 * (width * y + x);
+
+        if (x >= 0 && x < (int) width && y >= 0 && y < (int) height) {
+          rgb[ofs + 0] = (color & 0xff0000) >> 16;
+          rgb[ofs + 1] = (color & 0x00ff00) >> 8;
+          rgb[ofs + 2] = (color & 0x0000ff);
+        }
+      }
     }
-                
-    rgb[ofs + 0] = (color & 0xff0000) >> 16;
-    rgb[ofs + 1] = (color & 0x00ff00) >> 8;
-    rgb[ofs + 2] = (color & 0x0000ff);
   }
 }