partially done work on total source tree rework, separation of engine context and game context, generalization of renderer for different backends as well as web platform target

src/rendering/twn_rendering_c.h

@@ -0,0 +1,145 @@
+#ifndef RENDERING_INTERNAL_API_H
+#define RENDERING_INTERNAL_API_H
+
+#include "townengine/textures/internal_api.h"
+#include "townengine/util.h"
+#include "townengine/macros/option.h"
+
+#include <SDL2/SDL.h>
+
+#include <stdbool.h>
+
+extern t_matrix4 camera_projection_matrix;
+extern t_matrix4 camera_look_at_matrix;
+
+struct sprite_primitive {
+    t_frect rect;
+    t_color color;
+    float rotation;
+    t_texture_key texture_key;
+    bool flip_x;
+    bool flip_y;
+    bool repeat;
+
+    m_option_list(
+        t_fvec2, texture_origin )
+};
+
+struct rect_primitive {
+    t_frect rect;
+    t_color color;
+};
+
+struct circle_primitive {
+    float radius;
+    t_color color;
+    t_fvec2 position;
+};
+
+struct text_primitive {
+    t_color color;
+    t_fvec2 position;
+    char *text;
+    const char *font;
+    int height_px;
+};
+
+enum primitive_2d_type {
+    PRIMITIVE_2D_SPRITE,
+    PRIMITIVE_2D_RECT,
+    PRIMITIVE_2D_CIRCLE,
+    PRIMITIVE_2D_TEXT,
+};
+
+struct primitive_2d {
+    enum primitive_2d_type type;
+
+    union {
+        struct sprite_primitive sprite;
+        struct rect_primitive rect;
+        struct circle_primitive circle;
+        struct text_primitive text;
+    };
+};
+
+/* union for in-place recalculation of texture coordinates */
+union uncolored_space_triangle {
+    /* pending for sending, uvs are not final as texture atlases could update */
+    struct uncolored_space_triangle_primitive {
+        t_fvec3 v0;
+        t_fvec2 uv0; /* in pixels */
+        t_fvec3 v1;
+        t_fvec2 uv1; /* in pixels */
+        t_fvec3 v2;
+        t_fvec2 uv2; /* in pixels */
+    } primitive;
+
+    /* TODO: have it packed? */
+    /* structure that is passed in opengl vertex array */
+    struct uncolored_space_triangle_payload {
+        t_fvec3 v0;
+        t_fvec2 uv0;
+        t_fvec3 v1;
+        t_fvec2 uv1;
+        t_fvec3 v2;
+        t_fvec2 uv2;
+    } payload;
+};
+
+/* batch of primitives with overlapping properties */
+struct mesh_batch {
+    uint8_t *primitives;
+};
+
+struct mesh_batch_item {
+    t_texture_key key;
+    struct mesh_batch value;
+};
+
+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,
+                            size_t num_vertices,
+                            SDL_Vertex **vertices_out,
+                            int **indices_out);
+
+struct sprite_batch {
+    size_t size;             /* how many primitives are in current batch */
+    enum texture_mode mode;
+    bool constant_colored;   /* whether colored batch is uniformly colored */
+    bool repeat;             /* whether repeat is needed */
+} collect_sprite_batch(const struct primitive_2d primitives[], size_t len);
+
+void render_sprites(const struct primitive_2d primitives[],
+                    const struct sprite_batch batch);
+
+void draw_uncolored_space_traingle_batch(struct mesh_batch *batch,
+                                         t_texture_key texture_key);
+
+void render_text(const struct text_primitive *text);
+
+void text_cache_init(struct text_cache *cache);
+
+void text_cache_deinit(struct text_cache *cache);
+
+#endif