add outstanding changes

1 files changed, 30 insertions, 0 deletions

diff --git a/km-draw.c b/km-draw.c
new file mode 100644
index 0000000..7f59df3
--- /dev/null
+++ b/km-draw.c
@@ -0,0 +1,30 @@
+#include <stdint.h> // size_t
+#include "util.h"
+#include "km.h"
+
+void
+km_set_draw(
+  const km_set_t * const set,
+  uint8_t * const rgb,
+  const size_t width,
+  const size_t height,
+  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
+      );
+    }
+                
+    rgb[ofs + 0] = (color & 0xff0000) >> 16;
+    rgb[ofs + 1] = (color & 0x00ff00) >> 8;
+    rgb[ofs + 2] = (color & 0x0000ff);
+  }
+}