billboards!

src/rendering/twn_text.c

@@ -175,7 +175,7 @@ static void text_draw_with(FontData* font_data, char* text, Vec2 position, Color
 
     const size_t len = SDL_strlen(text);
 
-    VertexBufferBuilder payload = build_vertex_buffer(vertex_array, get_text_payload_size() * len);
+    VertexBufferBuilder payload = build_vertex_buffer(vertex_array, sizeof (ElementIndexedQuadWithoutColor) * len);
 
     for (size_t i = 0; i < len; ++i) {
         const char c = text[i];
@@ -318,3 +318,73 @@ float draw_text_width(const char *string, float height, const char *font) {
     
     return (float)length * font_data->scale_factor;
 }
+
+
+bool push_text_payload_to_vertex_buffer_builder(FontData const *font_data,
+                                                VertexBufferBuilder *builder,
+                                                stbtt_aligned_quad quad)
+{
+    (void)font_data;
+
+    ElementIndexedQuadWithoutColor buffer_element = {
+        .v0 = (Vec2){ quad.x0, quad.y0 },
+        .v1 = (Vec2){ quad.x1, quad.y0 },
+        .v2 = (Vec2){ quad.x1, quad.y1 },
+        .v3 = (Vec2){ quad.x0, quad.y1 },
+
+        .uv0 = (Vec2){ quad.s0, quad.t0 },
+        .uv1 = (Vec2){ quad.s1, quad.t0 },
+        .uv2 = (Vec2){ quad.s1, quad.t1 },
+        .uv3 = (Vec2){ quad.s0, quad.t1 },
+    };
+
+    return push_to_vertex_buffer_builder(builder, &buffer_element, sizeof buffer_element);
+}
+
+
+void finally_draw_text(FontData const *font_data,
+                       size_t len,
+                       Color color,
+                       VertexBuffer buffer)
+{
+    DeferredCommandDraw command = {0};
+
+    command.vertices = (AttributeArrayPointer) {
+        .arity = 2,
+        .type = GL_FLOAT,
+        .stride = offsetof(ElementIndexedQuadWithoutColor, v1),
+        .offset = offsetof(ElementIndexedQuadWithoutColor, v0),
+        .buffer = buffer
+    };
+
+    command.texcoords = (AttributeArrayPointer) {
+        .arity = 2,
+        .type = GL_FLOAT,
+        .stride = offsetof(ElementIndexedQuadWithoutColor, v1),
+        .offset = offsetof(ElementIndexedQuadWithoutColor, uv0),
+        .buffer = buffer
+    };
+
+    command.constant_colored = true;
+    command.color = color;
+
+    command.gpu_texture = font_data->texture;
+    command.uses_gpu_key = true;
+    command.textured = true;
+
+    command.element_buffer = get_quad_element_buffer();
+    command.element_count = 6 * (GLsizei)len;
+    command.range_end = 6 * (GLsizei)len;
+
+    use_texture_mode(TEXTURE_MODE_GHOSTLY);
+
+    DeferredCommand final_command = {
+        .type = DEFERRED_COMMAND_TYPE_DRAW,
+        .draw = command
+    };
+
+    arrpush(deferred_commands, final_command);
+
+    /* TODO: why doesn't it get restored if not placed here? */
+    // glDepthMask(GL_TRUE);
+}