1 files changed, 28 insertions, 0 deletions
diff --git a/render.c b/render.c
index 07af8cf..ff7670b 100644
--- a/render.c
+++ b/render.c
@@ -114,6 +114,34 @@ void ren_map(
 	}
 }
 
+void ren_cmap(
+	Renderer* r,
+	int x,
+	int y,
+	const struct Rect* re,
+	const Bitmap* bm
+) {
+	Rect rect, su = *re;
+	const unsigned* data = (const unsigned*)&bm[1];
+	int i, j, sx, sy, ex, ey;
+	rect.x = x;
+	rect.y = y;
+	rect.w = re->w;
+	rect.h = re->h;
+	rect_clipsr(&rect, &su, r->clip);
+	ex = rect.x + rect.w;
+	ey = rect.y + rect.h;
+	for (j = rect.y, sy = su.y; j < ey; j++, sy++) {
+		for (i = rect.x, sx = su.x; i < ex; i++, sx++) {
+			int di = (i + j * r->w);
+			int si = (sx + sy * bm->w);
+			int bit = (1 << (si & 0x1f));
+			bit &= data[si >> 5];
+			r->t[di >> 5] &= ~((1 << (di & 0x1f)) * (bit != 0));
+		}
+	}
+}
+
 void ren_rect(
 	Renderer* r,
 	const struct Rect* re