Add coll::rectIntersect (#194)

samples/rect/main.um

@@ -0,0 +1,26 @@
+import (
+	"window.um"
+	"canvas.um"
+	"th.um"
+	"input.um"
+	"image.um"
+	"rect.um"
+	"coll.um"
+)
+
+fn init*() {
+	window::setup("Rect test", 800, 600)
+
+	window::onFrame.register({
+		a := rect::mk(400-40, 300-40, 80, 80)
+		b := rect::mk(input::getMousePos().x-25, input::getMousePos().y-25, 50, 50)
+
+		canvas::drawRectLines(0x999999FF, a)
+		canvas::drawRectLines(0x000000FF, b)
+
+		if coll::rectToRect(a, b) {
+			r := coll::rectIntersect(a, b)
+			canvas::drawRectLines(0xFF0000FF, r)
+		}
+	})
+}

src/bindings.c

@@ -1334,6 +1334,15 @@ umth_coll_rect_to_rect(UmkaStackSlot *p, UmkaStackSlot *r)
 	umkaGetResult(p, r)->intVal = th_rect_to_rect(&r1, &r2);
 }
 
+void
+umth_coll_rect_intersect(UmkaStackSlot *p, UmkaStackSlot *r)
+{
+	th_rect r1 = *(th_rect *)umkaGetParam(p, 0);
+	th_rect r2 = *(th_rect *)umkaGetParam(p, 1);
+
+	*(th_rect *)umkaGetResult(p, r)->ptrVal = th_rect_intersect(r1, r2);
+}
+
 // fn umth_nav_mesh_add_quad(m: ^Mesh, q: th::Quad)
 void
 umth_nav_mesh_add_quad(UmkaStackSlot *p, UmkaStackSlot *r)
@@ -1497,13 +1506,14 @@ _th_umka_bind(void *umka)
 	umkaAddFunc(umka, "umth_transform_vf2", &umth_transform_vf2);
 	umkaAddFunc(umka, "umth_transform_transform", &umth_transform_transform);
 
-	// colisions
+	// collisions
 	umkaAddFunc(umka, "umth_coll_line_to_line", &umth_coll_line_to_line);
 	umkaAddFunc(umka, "umth_coll_point_to_quad", &umth_coll_point_to_quad);
 	umkaAddFunc(umka, "umth_coll_line_to_quad", &umth_coll_line_to_quad);
 	umkaAddFunc(umka, "umth_coll_quad_to_quad", &umth_coll_quad_to_quad);
 	umkaAddFunc(umka, "umth_coll_point_to_rect", &umth_coll_point_to_rect);
 	umkaAddFunc(umka, "umth_coll_rect_to_rect", &umth_coll_rect_to_rect);
+	umkaAddFunc(umka, "umth_coll_rect_intersect", &umth_coll_rect_intersect);
 
 	// nav
 	umkaAddFunc(umka, "umth_nav_mesh_add_quad", &umth_nav_mesh_add_quad);

src/collisions.c

@@ -214,3 +214,14 @@ th_coll_point_on_rect(th_vf2 p, th_rect *r)
 {
 	return p.x >= r->x && p.y >= r->y && p.x <= r->x + r->w && p.y <= r->y + r->h;
 }
+
+th_rect
+th_rect_intersect(th_rect a, th_rect b)
+{
+	float x = fmax(a.x, b.x);
+	float y = fmax(a.y, b.y);
+	float w = fmin(a.x + a.w, b.x + b.w) - x;
+	float h = fmin(a.y + a.h, b.y + b.h) - y;
+
+	return (th_rect){x, y, w, h};
+}

src/staembed.c

@@ -2881,6 +2881,14 @@ const char *th_em_modulesrc[] = {
 "\treturn umth_coll_rect_to_rect(r1, r2)\n"
 "}\n"
 "\n"
+"fn umth_coll_rect_intersect(r1, r2: rect::Rect): rect::Rect\n"
+"//~~fn rectIntersect\n"
+"// Get the intersection of two rects.\n"
+"fn rectIntersect*(r1, r2: rect::Rect): rect::Rect {\n"
+"//~~\n"
+"\treturn umth_coll_rect_intersect(r1, r2)\n"
+"}\n"
+"\n"
 "",
 "import(\"image.um\")\n"
 "\n"
@@ -6253,6 +6261,14 @@ const char *th_em_moduledocs[] = {
 "\n"
 "---------\n"
 "\n"
+"fn rectIntersect\n"
+"\n"
+"fn rectIntersect*(r1, r2: rect::Rect): rect::Rect {\n"
+"\n"
+"Get the intersection of two rects.\n"
+"\n"
+"---------\n"
+"\n"
 "",
 "Placeholder images\n"
 "\n"

src/thextdata.h

@@ -28,6 +28,7 @@ THEXT(uu, th_coll_on_tilemap, th_ent *e, th_tmap *t, th_vf2 *ic, th_vf2 *tc);
 THEXT(uu, th_coll_point_on_rect, th_vf2 p, th_rect *r);
 THEXT(uu, th_rect_to_rect, th_rect *r1, th_rect *r2);
 THEXT(uu, th_line_to_tilemap, th_vf2 b, th_vf2 e, th_tmap *t, th_vf2 *ic);
+THEXT(th_rect, th_rect_intersect, th_rect a, th_rect b);
 THEXT(th_quad, th_ent_transform, th_ent *e);
 THEXT(void, th_ent_draw, th_ent *o);
 THEXT(void, th_ent_getcoll, th_ent *e, th_ent **scene, uu count, uu *collC, uu maxColls, th_coll *colls);

src/tophat.h

@@ -446,6 +446,8 @@ uu
 th_rect_to_rect(th_rect *r1, th_rect *r2);
 uu
 th_line_to_tilemap(th_vf2 b, th_vf2 e, th_tmap *t, th_vf2 *ic);
+th_rect
+th_rect_intersect(th_rect a, th_rect b);
 
 // entity
 th_quad

umka/coll.um

@@ -55,3 +55,11 @@ fn rectToRect*(r1, r2: rect::Rect): bool {
 	return umth_coll_rect_to_rect(r1, r2)
 }
 
+fn umth_coll_rect_intersect(r1, r2: rect::Rect): rect::Rect
+//~~fn rectIntersect
+// Get the intersection of two rects.
+fn rectIntersect*(r1, r2: rect::Rect): rect::Rect {
+//~~
+	return umth_coll_rect_intersect(r1, r2)
+}
+