twn_rendering -> twn_draw

src/rendering/twn_draw_c.h

@@ -0,0 +1,236 @@
+#ifndef TWN_DRAW_C_H
+#define TWN_DRAW_C_H
+
+#include "twn_textures_c.h"
+#include "twn_text_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 Matrix4 camera_projection_matrix;
+extern Matrix4 camera_look_at_matrix;
+
+#define QUAD_ELEMENT_BUFFER_LENGTH (65536 / 6)
+
+
+typedef GLuint VertexBuffer;
+
+typedef struct VertexBufferBuilder {
+    size_t bytes_left;
+    void *mapping;
+} VertexBufferBuilder;
+
+
+typedef struct SpritePrimitive {
+    Rect rect;
+    Color color;
+    float rotation;
+    TextureKey texture_key;
+    bool flip_x;
+    bool flip_y;
+    bool repeat;
+
+    m_option_list(
+        Rect, texture_region )
+} SpritePrimitive;
+
+typedef struct RectPrimitive {
+    Rect rect;
+    Color color;
+} RectPrimitive;
+
+typedef struct CirclePrimitive {
+    float radius;
+    Color color;
+    Vec2 position;
+} CirclePrimitive;
+
+typedef struct TextPrimitive {
+    Color color;
+    Vec2 position;
+    char *text;
+    const char *font;
+    int height_px;
+} TextPrimitive;
+
+typedef enum Primitive2DType {
+    PRIMITIVE_2D_SPRITE,
+    PRIMITIVE_2D_RECT,
+    PRIMITIVE_2D_CIRCLE,
+    PRIMITIVE_2D_TEXT,
+} Primitive2DType;
+
+typedef struct Primitive2D {
+    Primitive2DType type;
+
+    union {
+        SpritePrimitive sprite;
+        RectPrimitive rect;
+        CirclePrimitive circle;
+        TextPrimitive text;
+    };
+} Primitive2D;
+
+/* union for in-place recalculation of texture coordinates */
+union UncoloredSpaceTriangle {
+    /* pending for sending, uvs are not final as texture atlases could update */
+    struct UncoloredSpaceTrianglePrimitive {
+        Vec3 v0;
+        Vec2 uv0; /* in pixels */
+        Vec3 v1;
+        Vec2 uv1; /* in pixels */
+        Vec3 v2;
+        Vec2 uv2; /* in pixels */
+    } primitive;
+
+    /* TODO: have it packed? */
+    /* structure that is passed in opengl vertex array */
+    struct UncoloredSpaceTrianglePayload {
+        Vec3 v0;
+        Vec2 uv0;
+        Vec3 v1;
+        Vec2 uv1;
+        Vec3 v2;
+        Vec2 uv2;
+    } payload;
+};
+
+/* batch of primitives with overlapping properties */
+typedef struct MeshBatch {
+    uint8_t *primitives;
+} MeshBatch;
+
+typedef struct MeshBatchItem {
+    TextureKey key;
+    struct MeshBatch value;
+} MeshBatchItem;
+
+typedef struct TextCache {
+    struct FontData **data;
+} TextCache;
+
+
+/* renders the background, then the primitives in all render queues */
+void render(void);
+
+/* clears all render queues */
+void render_queue_clear(void);
+
+void create_circle_geometry(Vec2 position,
+                            Color color,
+                            float radius,
+                            size_t num_vertices,
+                            SDL_Vertex **vertices_out,
+                            int **indices_out);
+
+struct SpriteBatch {
+    size_t size;             /* how many primitives are in current batch */
+    TextureMode mode;
+    bool constant_colored;   /* whether colored batch is uniformly colored */
+    bool repeat;             /* whether repeat is needed */
+} collect_sprite_batch(const Primitive2D primitives[], size_t len);
+
+void render_sprites(const Primitive2D primitives[],
+                    const struct SpriteBatch batch);
+
+void draw_uncolored_space_traingle_batch(MeshBatch *batch,
+                                         TextureKey texture_key);
+
+/* text */
+
+void render_text(const TextPrimitive *text);
+
+void text_cache_init(TextCache *cache);
+
+void text_cache_deinit(TextCache *cache);
+
+void text_cache_reset_arena(TextCache *cache);
+
+/* vertex buffer */
+
+VertexBuffer create_vertex_buffer(void);
+
+void delete_vertex_buffer(VertexBuffer buffer);
+
+void specify_vertex_buffer(VertexBuffer buffer, void *data, size_t bytes);
+
+/* uses present in 1.5 buffer mapping feature */
+VertexBufferBuilder build_vertex_buffer(VertexBuffer 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(VertexBufferBuilder *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 CirclePrimitive *circle);
+
+void render_rectangle(const RectPrimitive *rectangle);
+
+void use_space_pipeline(void);
+
+void use_2d_pipeline(void);
+
+void use_texture_mode(TextureMode mode);
+
+void finally_render_sprites(Primitive2D const primitives[],
+                            struct SpriteBatch batch,
+                            VertexBuffer buffer);
+
+size_t get_sprite_payload_size(struct SpriteBatch batch);
+
+bool push_sprite_payload_to_vertex_buffer_builder(struct SpriteBatch batch,
+                                                  VertexBufferBuilder *builder,
+                                                  Vec2 v0, Vec2 v1, Vec2 v2, Vec2 v3,
+                                                  Vec2 uv0, Vec2 uv1, Vec2 uv2, Vec2 uv3,
+                                                  Color color);
+
+void finally_draw_uncolored_space_traingle_batch(MeshBatch const *batch,
+                                                 TextureKey texture_key,
+                                                 VertexBuffer buffer);
+
+size_t get_text_payload_size(void);
+
+bool push_text_payload_to_vertex_buffer_builder(FontData const *font_data,
+                                                VertexBufferBuilder *builder,
+                                                stbtt_aligned_quad quad);
+
+void finally_draw_text(FontData const *font_data,
+                       size_t len,
+                       Color color,
+                       VertexBuffer buffer);
+
+void render_skybox(void);
+
+void finally_render_skybox(char *paths_in_use);
+
+void apply_fog(void);
+
+void finally_apply_fog(float start, float end, float density, Color color);
+
+void pop_fog(void);
+
+void finally_pop_fog(void);
+
+#endif