Allow display wrapping to be specified per shape

main.c

@@ -32,6 +32,7 @@ typedef struct {
 	int entity;
 	unsigned vert_count;
 	vec2_t verts[MAX_VERTS];
+	uint8_t flags;
 } shape_t;
 
 typedef struct {
@@ -57,6 +58,7 @@ static shape_t shapes[MAX_SHAPES] = {
 			{ 0.0, -0.04 },
 			{ -0.05, -0.07 },
 		},
+		.flags = WRAP | CONNECT,
 	},
 	{
 		.visible = false,
@@ -67,6 +69,7 @@ static shape_t shapes[MAX_SHAPES] = {
 			{ 0.015, -0.07 },
 			{ -0.015, -0.07 },
 		},
+		.flags = WRAP | CONNECT,
 	},
 };
 
@@ -114,6 +117,7 @@ static void shoot()
 	s->entity = id;
 	s->vert_count = NELEMS(shot_verts);
 	memcpy(s->verts, shot_verts, sizeof(shot_verts));
+	s->flags = 0;
 
 	e->shapes[0] = shape_id;
 	e->shape_count = 1;
@@ -251,13 +255,12 @@ static void update()
 				e->pos.x -= 2 * aspect;
 			else if (e->pos.x < -aspect)
 				e->pos.x += 2 * aspect;
-		} else {
-			if (e->pos.y > 1 || e->pos.y <= -1 || e->pos.x >= aspect
+		} else if (
+		    e->pos.y > 1 || e->pos.y <= -1 || e->pos.x >= aspect
 		    || e->pos.x < -aspect) {
 			remove_entity(i--);
 			continue;
 		}
-		}
 
 		transforms[i] = entity_transform(i);
 	}
@@ -270,7 +273,9 @@ static void draw()
 			continue;
 
 		const mat3_t transform = transforms[shapes[i].entity];
-		renderer_draw(shapes[i].verts, shapes[i].vert_count, transform);
+		renderer_draw(
+		    shapes[i].verts, shapes[i].vert_count, transform,
+		    shapes[i].flags);
 	}
 }
 

renderer.c

@@ -32,7 +32,7 @@ static void set_pixel(uint32_t x, uint32_t y)
 	fbs[back].buf[offset] = 0xff'ff'ff;
 }
 
-static void draw_line(vec3_t v1, vec3_t v2)
+static void draw_line(vec3_t v1, vec3_t v2, uint8_t flags)
 {
 	const float delta_x = v2.x - v1.x;
 	const float delta_y = v2.y - v1.y;
@@ -43,16 +43,20 @@ static void draw_line(vec3_t v1, vec3_t v2)
 
 		for (unsigned i = 0; i <= step; ++i) {
 			float x = roundf(v1.x + i * step_x);
+			float y = roundf(v1.y + i * step_y);
+
+			if (flags & WRAP) {
 				if (x >= width)
 					x -= width;
 				else if (x < 0)
 					x += width;
-
-			float y = roundf(v1.y + i * step_y);
 				if (y >= height)
 					y -= height;
 				else if (y < 0)
 					y += height;
+			} else if (x >= width || x < 0 || y >= height || y < 0) {
+				continue;
+			}
 
 			set_pixel(x, y);
 		}
@@ -141,13 +145,17 @@ void renderer_swap()
 	back = (back + 1) & 1;
 }
 
-void renderer_draw(const vec2_t *vs, unsigned count, mat3_t model)
+void renderer_draw(
+    const vec2_t *vs, unsigned count, mat3_t model, uint8_t flags)
 {
 	mat3_t transform = mat3_mul_mat3(view, model);
 	assert(count < MAX_VERTS);
+
 	for (unsigned i = 0; i < count; ++i)
 		vert_buf[i] = mat3_mul_vec3(transform, vec2_extend(vs[i]));
 	for (unsigned i = 1; i < count; ++i)
-		draw_line(vert_buf[i - 1], vert_buf[i]);
-	draw_line(vert_buf[count - 1], vert_buf[0]);
+		draw_line(vert_buf[i - 1], vert_buf[i], flags);
+
+	if (flags & CONNECT)
+		draw_line(vert_buf[count - 1], vert_buf[0], flags);
 }

renderer.h

@@ -7,6 +7,9 @@
 
 #define MAX_VERTS 8U
 
+#define WRAP 1
+#define CONNECT (1 << 1)
+
 typedef struct {
 	int drm_fd;
 	float aspect;
@@ -19,6 +22,7 @@ void renderer_handle();
 void renderer_clear();
 void renderer_swap();
 
-void renderer_draw(const vec2_t *vs, unsigned count, mat3_t model);
+void renderer_draw(
+    const vec2_t *vs, unsigned count, mat3_t model, uint8_t flags);
 
 #endif