rendering.c: sprite rotation

src/game/scenes/ingame.c

@@ -11,6 +11,23 @@ static void ingame_tick(struct state *state) {
     world_drawdef(scn->world);
     player_calc(scn->player);
 
+    push_sprite_ex((t_frect){ .x = 32, .y = 32, .w = 64, .h = 64 }, (t_push_sprite_args){
+        .path = "/assets/player/baron-walk.png",
+        .color = (t_color){255, 255, 255, 255},
+        .rotation = (float)M_PI * 2 * (float)(ctx.tick_count % 64) / 64,
+        .blend = true });
+
+    push_sprite_ex((t_frect){ .x = 64, .y = 32, .w = 64, .h = 64 }, (t_push_sprite_args){
+        .path = "/assets/player/baron-walk.png",
+        .color = (t_color){255, 255, 255, 255},
+        .rotation = (float)M_PI / 64,
+        .blend = true });
+
+    push_sprite_ex((t_frect){ .x = 96, .y = 32, .w = 64, .h = 64 }, (t_push_sprite_args){
+        .path = "/assets/player/baron-walk.png",
+        .color = (t_color){255, 255, 255, 255},
+        .blend = true });
+
     unfurl_triangle("/assets/big-violet.png",
                     (t_fvec3){ -1, -1, 0 },
                     (t_fvec3){ 1, -1, 0 },

src/rendering.c

@@ -90,6 +90,7 @@ static void render_2d(void) {
                     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
                     glEnable(GL_DEPTH_TEST);
                     glDepthFunc(GL_ALWAYS);
+                    glDepthRange((double)batch_count / UINT16_MAX, 1.0);
                     glDisable(GL_ALPHA_TEST);
 
                     render_sprites(current, batch.size, false);

src/rendering/sprites.h

@@ -135,6 +135,8 @@ static void render_sprites(const struct primitive_2d primitives[],
 	        const float xr = (float)srcrect.x / (float)dims.w;
 	        const float yr = (float)srcrect.y / (float)dims.h;
 
+	        /* non-rotated case */
+	        if (sprite.rotation == 0.0f) {
 	            payload[i] = (struct sprite_primitive_payload) {
 	                /* upper-left */
 	                .v0 = {
@@ -174,6 +176,54 @@ static void render_sprites(const struct primitive_2d primitives[],
 	                .c2 = sprite.color,
 	                .c3 = sprite.color,
 	            };
+	        } else {
+	        	/* rotated case */
+	        	const t_fvec2 c = frect_center(sprite.rect);
+	        	const t_fvec2 d = {
+	        		.x = (cosf(sprite.rotation + (float)M_PI_4) * sprite.rect.w) * (float)M_SQRT1_2,
+	        		.y = (sinf(sprite.rotation + (float)M_PI_4) * sprite.rect.h) * (float)M_SQRT1_2,
+	        	};
+
+	            payload[i] = (struct sprite_primitive_payload) {
+	                /* upper-left */
+	                .v0 = {
+	                    c.x - d.x,
+	                    c.y - d.y },
+	                .uv0 = {
+	                    xr + wr * sprite.flip_x,
+	                    yr + hr * sprite.flip_y, },
+
+	                /* bottom-left */
+	                .v1 = {
+	                    c.x - d.y,
+	                    c.y + d.x },
+	                .uv1 = {
+	                    xr + wr * sprite.flip_x,
+	                    yr + hr * !sprite.flip_y, },
+
+	                /* bottom-right */
+	                .v2 = {
+	                    c.x + d.x,
+	                    c.y + d.y },
+	                .uv2 = {
+	                    xr + wr * !sprite.flip_x,
+	                    yr + hr * !sprite.flip_y, },
+
+	                /* upper-right */
+	                .v3 = {
+	                    c.x + d.y,
+	                    c.y - d.x },
+	                .uv3 = {
+	                    xr + wr * !sprite.flip_x,
+	                    yr + hr * sprite.flip_y, },
+
+	                /* equal for all (flat shaded) */
+	                .c0 = sprite.color,
+	                .c1 = sprite.color,
+	                .c2 = sprite.color,
+	                .c3 = sprite.color,
+	            };
+	        }
         }
 
         glUnmapBuffer(GL_ARRAY_BUFFER);

src/util.c

@@ -186,6 +186,14 @@ t_frect to_frect(t_rect rect) {
 }
 
 
+t_fvec2 frect_center(t_frect rect) {
+    return (t_fvec2){
+        .x = rect.x + rect.w / 2,
+        .y = rect.y + rect.h / 2,
+    };
+}
+
+
 t_fvec2 fvec2_from_vec2(t_vec2 vec) {
     return (t_fvec2) {
         .x = (float)vec.x,

src/util.h

@@ -77,29 +77,6 @@ typedef struct color {
 } t_color;
 
 
-/* a rectangle with the origin at the upper left (integer) */
-typedef struct rect {
-    int x, y;
-    int w, h;
-} t_rect;
-
-
-bool intersect_rect(const t_rect *a, const t_rect *b, t_rect *result);
-
-
-/* a rectangle with the origin at the upper left (floating point) */
-typedef struct frect {
-    float x, y;
-    float w, h;
-} t_frect;
-
-
-bool intersect_frect(const t_frect *a, const t_frect *b, t_frect *result);
-
-/* TODO: generics and specials (see m_to_fvec2() for an example)*/
-t_frect to_frect(t_rect rect);
-
-
 /* a point in some space (integer) */
 typedef struct vec2 {
     int x, y;
@@ -125,6 +102,30 @@ typedef struct shvec2 {
 } t_shvec2;
 
 
+/* a rectangle with the origin at the upper left (integer) */
+typedef struct rect {
+    int x, y;
+    int w, h;
+} t_rect;
+
+
+/* a rectangle with the origin at the upper left (floating point) */
+typedef struct frect {
+    float x, y;
+    float w, h;
+} t_frect;
+
+
+bool intersect_rect(const t_rect *a, const t_rect *b, t_rect *result);
+
+bool intersect_frect(const t_frect *a, const t_frect *b, t_frect *result);
+
+/* TODO: generics and specials (see m_to_fvec2() for an example)*/
+t_frect to_frect(t_rect rect);
+
+t_fvec2 frect_center(t_frect rect);
+
+
 /* aren't macros to prevent double evaluation with side effects */
 /* maybe could be inlined? i hope LTO will resolve this */
 t_fvec2 fvec2_from_vec2(t_vec2 vec);