Allow the clipping of rendering

1 files changed, 30 insertions, 14 deletions

diff --git a/teensy/teensy_renderer.c b/teensy/teensy_renderer.c
index 0dd4fc3..eee67a3 100644
--- a/teensy/teensy_renderer.c
+++ b/teensy/teensy_renderer.c
@@ -42,6 +42,14 @@ void image_bounds_check(ty_Image img, ty_Vec2i pos)
 #endif
 }
 
+static
+ty_Vec2i clamp_point(ty_Vec2i p, ty_Recti rect)
+{
+    p.x = fmin(fmax(p.x, rect.x), rect.x + rect.w);
+    p.y = fmin(fmax(p.y, rect.y), rect.y + rect.h);
+    return p;
+}
+
 void ty_init_renderer(void)
 {
     r.screen = ty_create_image(
@@ -50,6 +58,8 @@ void ty_init_renderer(void)
         NULL
     );
     r.target = r.screen;
+
+    ty_draw_set_clip(TY_CLIP_NONE);
 }
 
 void ty_deinit_renderer(void)
@@ -136,6 +146,20 @@ void ty_draw_set_target(const ty_Image *img)
     memcpy(&r.target, img, sizeof(r.target));
 }
 
+void ty_draw_set_clip(ty_Recti clip)
+{
+    if (clip.w <= 0 || clip.h <= 0)
+        clip = screenspace();
+
+    ty_Vec2i start = clamp_point(ty_recti_start(clip), screenspace());
+    ty_Vec2i end = clamp_point(ty_recti_end(clip), screenspace());
+
+    r.clip = ty_recti(
+        start.x, start.y,
+        end.x - start.x, end.y - start.y
+    );
+}
+
 void ty_draw_clear(ty_Color col)
 {
     assert(is_renderer_init());
@@ -144,20 +168,12 @@ void ty_draw_clear(ty_Color col)
     }
 }
 
-static
-ty_Vec2i clamp_point(ty_Vec2i p, 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(ty_Image img, ty_Vec2i pos)
 {
-    ty_Vec2i p1 = clamp_point(ty_vec2i(pos.x, pos.y), screenspace());
+    ty_Vec2i p1 = clamp_point(ty_vec2i(pos.x, pos.y), r.clip);
     ty_Vec2i p2 = clamp_point(
         ty_vec2i(pos.x + img.width, pos.y + img.height),
-        screenspace()
+        r.clip
     );
 
     for (int dy = p1.y; dy < p2.y; dy++) {
@@ -182,8 +198,8 @@ void ty_draw_image_ex(
     ty_Recti src,
     ty_Recti dst
 ) {
-    ty_Vec2i p1 = clamp_point(ty_recti_start(dst), screenspace());
-    ty_Vec2i p2 = clamp_point(ty_recti_end(dst), screenspace());
+    ty_Vec2i p1 = clamp_point(ty_recti_start(dst), r.clip);
+    ty_Vec2i p2 = clamp_point(ty_recti_end(dst), r.clip);
 
     for (int dy = p1.y; dy < p2.y; dy++) {
         for (int dx = p1.x; dx < p2.x; dx++) {
@@ -237,8 +253,8 @@ void ty_draw_image_rot(
 
 void ty_draw_rect(ty_Recti rect, ty_Color color)
 {
-    ty_Vec2i p1 = clamp_point(ty_vec2i(rect.x, rect.y), screenspace());
-    ty_Vec2i p2 = clamp_point(ty_recti_end(rect), screenspace());
+    ty_Vec2i p1 = clamp_point(ty_vec2i(rect.x, rect.y), r.clip);
+    ty_Vec2i p2 = clamp_point(ty_recti_end(rect), r.clip);
 
     for (int dy = p1.y; dy < p2.y; dy++) {
         for (int dx = p1.x; dx < p2.x; dx++) {