billboards!

src/rendering/twn_draw_c.h

@@ -55,16 +55,16 @@ typedef struct RectPrimitive {
 } RectPrimitive;
 
 typedef struct CirclePrimitive {
+    Vec2 position;
     float radius;
     Color color;
-    Vec2 position;
 } CirclePrimitive;
 
 typedef struct TextPrimitive {
-    Color color;
     Vec2 position;
     char *text;
     const char *font;
+    Color color;
     int height_px;
 } TextPrimitive;
 
@@ -76,7 +76,7 @@ typedef enum Primitive2DType {
 } Primitive2DType;
 
 typedef struct Primitive2D {
-    Primitive2DType type;
+    Primitive2DType type; /* TODO: separate to structure of arrays for more efficient memory usage? */
 
     union {
         SpritePrimitive sprite;
@@ -97,6 +97,14 @@ typedef struct UncoloredSpaceTriangle {
     Vec2 uv2; /* in pixels */
 } UncoloredSpaceTriangle;
 
+typedef struct SpaceBillboard {
+    Vec3 position;
+    Vec2 size;
+    Color color;
+    // TextureKey texture; /* is assumed from other places */
+    bool cylindrical;
+} SpaceBillboard;
+
 /* batch of primitives with overlapping properties */
 typedef struct MeshBatch {
     uint8_t *primitives; /* note: interpretation of it is arbitrary */
@@ -179,6 +187,26 @@ typedef struct ElementIndexedQuadWithoutColorWithoutTexture {
     Vec2 v3;
 } ElementIndexedQuadWithoutColorWithoutTexture;
 
+/* TODO: no color variant */
+typedef struct ElementIndexedBillboard {
+    /* upper-left */
+    Vec3 v0;
+    Vec2 uv0;
+    Color c0;
+    /* bottom-left */
+    Vec3 v1;
+    Vec2 uv1;
+    Color c1;
+    /* bottom-right */
+    Vec3 v2;
+    Vec2 uv2;
+    Color c2;
+    /* upper-right */
+    Vec3 v3;
+    Vec2 uv3;
+    Color c3;
+} ElementIndexedBillboard;
+
 
 /* renders the background, then the primitives in all render queues */
 void render(void);
@@ -207,9 +235,6 @@ struct QuadBatch collect_rect_batch(const Primitive2D primitives[], size_t len);
 void render_sprite_batch(const Primitive2D primitives[], struct QuadBatch batch);
 void render_rect_batch(const Primitive2D primitives[], struct QuadBatch batch);
 
-void draw_uncolored_space_traingle_batch(MeshBatch *batch,
-                                         TextureKey texture_key);
-
 /* text */
 
 void render_text(const TextPrimitive *text);
@@ -280,8 +305,10 @@ bool push_quad_payload_to_vertex_buffer_builder(struct QuadBatch batch,
                                                 Color color);
 
 void finally_draw_uncolored_space_traingle_batch(MeshBatch const *batch,
-                                                 TextureKey texture_key,
-                                                 VertexBuffer buffer);
+                                                 TextureKey texture_key);
+
+void finally_draw_billboard_batch(MeshBatch const *batch,
+                                  TextureKey texture_key);
 
 size_t get_text_payload_size(void);