finally compiling and running, text still needs rework

src/rendering/twn_rendering_c.h

@@ -1,17 +1,35 @@
-#ifndef RENDERING_INTERNAL_API_H
-#define RENDERING_INTERNAL_API_H
+#ifndef TWN_RENDERING_C_H
+#define TWN_RENDERING_C_H
 
-#include "townengine/textures/internal_api.h"
-#include "townengine/util.h"
-#include "townengine/macros/option.h"
+#include "twn_textures_c.h"
+#include "twn_util.h"
+#include "twn_option.h"
 
 #include <SDL2/SDL.h>
+#include <stb_truetype.h>
+
+#ifdef EMSCRIPTEN
+#include <GLES2/gl2.h>
+#else
+#include <glad/glad.h>
+#endif
 
 #include <stdbool.h>
 
 extern t_matrix4 camera_projection_matrix;
 extern t_matrix4 camera_look_at_matrix;
 
+#define QUAD_ELEMENT_BUFFER_LENGTH (65536 / 6)
+
+
+typedef GLuint vertex_buffer;
+
+typedef struct vertex_buffer_builder {
+    size_t bytes_left;
+    void *mapping;
+} vertex_buffer_builder;
+
+
 struct sprite_primitive {
     t_frect rect;
     t_color color;
@@ -100,22 +118,13 @@ struct text_cache {
     struct font_data **data;
 };
 
+
 /* renders the background, then the primitives in all render queues */
 void render(void);
 
 /* clears all render queues */
 void render_queue_clear(void);
 
-void push_circle(t_fvec2 position, float radius, t_color color);
-
-void unfurl_triangle(const char *path,
-                     t_fvec3 v0,
-                     t_fvec3 v1,
-                     t_fvec3 v2,
-                     t_shvec2 uv0,
-                     t_shvec2 uv1,
-                     t_shvec2 uv2);
-
 void create_circle_geometry(t_fvec2 position,
                             t_color color,
                             float radius,
@@ -136,10 +145,77 @@ void render_sprites(const struct primitive_2d primitives[],
 void draw_uncolored_space_traingle_batch(struct mesh_batch *batch,
                                          t_texture_key texture_key);
 
+/* text */
+
 void render_text(const struct text_primitive *text);
 
 void text_cache_init(struct text_cache *cache);
 
 void text_cache_deinit(struct text_cache *cache);
 
+/* vertex buffer */
+
+vertex_buffer create_vertex_buffer(void);
+
+void delete_vertex_buffer(vertex_buffer buffer);
+
+void specify_vertex_buffer(vertex_buffer buffer, void *data, size_t bytes);
+
+/* uses present in 1.5 buffer mapping feature */
+vertex_buffer_builder build_vertex_buffer(vertex_buffer buffer, size_t bytes);
+
+/* collects bytes for sending to the gpu until all is pushed, which is when false is returned */
+bool push_to_vertex_buffer_builder(vertex_buffer_builder *builder,
+                                   void *bytes,
+                                   size_t size);
+
+/* state */
+
+void setup_viewport(int x, int y, int width, int height);
+
+void clear_draw_buffer(void);
+
+void swap_buffers(void);
+
+void set_depth_range(double low, double high);
+
+void bind_quad_element_buffer(void);
+
+void render_circle(const struct circle_primitive *circle);
+
+void render_rectangle(const struct rect_primitive *rectangle);
+
+void use_space_pipeline(void);
+
+void use_2d_pipeline(void);
+
+void use_texture_mode(enum texture_mode mode);
+
+void finally_render_sprites(struct primitive_2d const primitives[],
+                            struct sprite_batch batch,
+                            vertex_buffer buffer);
+
+size_t get_sprite_payload_size(struct sprite_batch batch);
+
+bool push_sprite_payload_to_vertex_buffer_builder(struct sprite_batch batch,
+                                                  vertex_buffer_builder *builder,
+                                                  t_fvec2 v0, t_fvec2 v1, t_fvec2 v2, t_fvec2 v3,
+                                                  t_fvec2 uv0, t_fvec2 uv1, t_fvec2 uv2, t_fvec2 uv3,
+                                                  t_color color);
+
+void finally_draw_uncolored_space_traingle_batch(struct mesh_batch const *batch,
+                                                 t_texture_key texture_key,
+                                                 vertex_buffer buffer);
+
+size_t get_text_payload_size(void);
+
+bool push_text_payload_to_vertex_buffer_builder(struct font_data const *font_data,
+                                                vertex_buffer_builder *builder,
+                                                stbtt_aligned_quad quad);
+
+void finally_draw_text(struct font_data const *font_data,
+                       size_t len,
+                       t_color color,
+                       vertex_buffer buffer);
+
 #endif