rotated iamges

1 files changed, 41 insertions, 4 deletions

diff --git a/teensy/teensy_renderer.c b/teensy/teensy_renderer.c
index d3f73fd..2104695 100644
--- a/teensy/teensy_renderer.c
+++ b/teensy/teensy_renderer.c
@@ -178,13 +178,50 @@ void ty_draw_image_ex(
     }
 }
 
+struct ty_vec2i clamp_point(struct ty_vec2i p, struct ty_recti rect)
+{
+    p.x = fmin(fmax(p.x, rect.x), rect.w);
+    p.y = fmin(fmax(p.y, rect.y), rect.h);
+    return p;
+}
+
+void ty_draw_image_rot(
+    struct ty_image img,
+    struct ty_vec2i pos,
+    struct ty_vec2i offset,
+    double rot
+) {
+    double s = sin(rot);
+    double c = cos(rot);
+ 
+    // x1 = c*x - s*y
+    // y1 = s*x + c*y
+
+    // FIXME: the corners of the rotated image get cut off.
+    for (int img_y = 0; img_y < img.height; img_y++) {
+        for (int img_x = 0; img_x < img.width; img_x++) {
+            double pixel_x = img_x + offset.x;
+            double pixel_y = img_y + offset.y;
+
+            int dx = floor(pixel_x * c - pixel_y * s - offset.x);
+            int dy = floor(pixel_x * s + pixel_y * c - offset.y);
+
+            if (dx < 0 || dx >= img.width || dy < 0 || dy >= img.height)
+                continue;
+
+            struct ty_color px = ty_img_get_pixel(img, ty_vec2i(dx, dy));
+            ty_img_set_pixel(r.screen, ty_vec2i(pos.x + img_x, pos.y + img_y), px);
+        }
+    }
+}
+
 void ty_draw_rect(struct ty_recti rect, struct ty_color color)
 {
-    int x1 = fmin(fmax(floor(rect.x), 0), r.screen.width);
-    int y1 = fmin(fmax(floor(rect.y), 0), r.screen.height);
+    int x1 = fmin(fmax(rect.x, 0), r.screen.width);
+    int y1 = fmin(fmax(rect.y, 0), r.screen.height);
 
-    int x2 = fmin(fmax(floor(rect.x + rect.w), 0), r.screen.width);
-    int y2 = fmin(fmax(floor(rect.y + rect.h), 0), r.screen.height);
+    int x2 = fmin(fmax(rect.x + rect.w, 0), r.screen.width);
+    int y2 = fmin(fmax(rect.y + rect.h, 0), r.screen.height);
 
     for (int dy = y1; dy < y2; dy++) {
         for (int dx = x1; dx < x2; dx++) {