add put_rect for direct rectangle rendering

include/engine.h

@@ -72,7 +72,24 @@ put_pixel(
 	uint32_t color
 );
 
+void
+put_rect(
+	uint32_t x, 
+	uint32_t y, 
+	uint32_t w, 
+	uint32_t h,
+	uint32_t color
+);
+
 void 
 clear_framebuffer(
 	uint32_t color
+);
+
+void
+put_char(
+	char c,
+	uint32_t x, 
+	uint32_t y,
+	uint8_t size
 );

src/engine/render.c

@@ -22,6 +22,25 @@ put_pixel(
 	}
 }
 
+/**
+ * draws a rectangle with its left-top corner at (x,y) with
+ * a width of 'w' and height of 'h' filled with color 'color'
+ */ 
+void
+put_rect(
+	uint32_t x, 
+	uint32_t y, 
+	uint32_t w, 
+	uint32_t h,
+	uint32_t color
+) {
+	for (int i = x; i < x + w; i++) {
+		for (int j = y; j < y + h; j++) {
+			put_pixel(i, j, color);
+		}
+	}
+}
+
 // fill the entire framebuffer with a given color
 void 
 clear_framebuffer(