make deferred draw primitives agnostic to backend

src/rendering/twn_deferred_commands.h

@@ -0,0 +1,112 @@
+#ifndef TWN_DEFERRED_COMMANDS_H
+#define TWN_DEFERRED_COMMANDS_H
+
+#include "twn_types.h"
+#include "twn_gpu_texture_c.h"
+#include "twn_textures_c.h"
+
+#include <stddef.h>
+#include <stdbool.h>
+
+
+typedef enum {
+    PIPELINE_NO,
+    PIPELINE_SPACE,
+    PIPELINE_2D,
+} Pipeline;
+
+
+typedef struct {
+    size_t offset;
+    uint32_t type;
+    uint32_t stride;
+    uint32_t buffer;
+    uint8_t arity; /* leave at 0 to signal pointer as unused */
+} AttributeArrayPointer;
+
+
+/* allows us to have generic way to issue draws as well as */
+/* deferring new draw calls while previous frame is still being drawn */
+typedef struct {
+    AttributeArrayPointer vertices;
+    AttributeArrayPointer texcoords;
+
+    bool constant_colored;
+    union {
+        AttributeArrayPointer colors;        
+        Color color;
+    };
+
+    bool textured, texture_repeat, uses_gpu_key;
+    TextureKey texture_key;
+    GPUTexture gpu_texture;
+
+    uint32_t element_buffer;
+    uint32_t element_count;
+    uint32_t range_start, range_end;
+
+    /* could be either `element_count` with supplied `element_buffer`, or this, but not both */
+    uint32_t primitive_count;
+
+    double depth_range_low, depth_range_high;
+} DeferredCommandDraw;
+
+
+typedef struct {
+    char *paths;
+} DeferredCommandDrawSkybox;
+
+
+typedef struct {
+    Color color;
+    bool clear_color;
+    bool clear_depth;
+    bool clear_stencil;
+} DeferredCommandClear;
+
+
+typedef struct {
+    Pipeline pipeline;
+} DeferredCommandUsePipeline;
+
+
+typedef struct {
+    TextureMode mode;
+} DeferredCommandUseTextureMode;
+
+
+typedef struct {
+    double low, high;
+} DeferredCommandDepthRange;
+
+
+typedef struct {
+    float start, end, density;
+    Color color;
+} DeferredCommandApplyFog;
+
+
+typedef struct {
+    enum DeferredCommandType {
+        DEFERRED_COMMAND_TYPE_DRAW,
+        DEFERRED_COMMAND_TYPE_DRAW_SKYBOX,
+        DEFERRED_COMMAND_TYPE_CLEAR,
+        DEFERRED_COMMAND_TYPE_USE_PIPIELINE,
+        DEFERRED_COMMAND_TYPE_USE_TEXTURE_MODE,
+        DEFERRED_COMMAND_TYPE_DEPTH_RANGE,
+        DEFERRED_COMMAND_TYPE_APPLY_FOG,
+        DEFERRED_COMMAND_TYPE_POP_FOG,
+    } type;
+
+    union {
+        DeferredCommandDraw draw;
+        DeferredCommandDrawSkybox draw_skybox;
+        DeferredCommandClear clear;
+        DeferredCommandUsePipeline use_pipeline;
+        DeferredCommandUseTextureMode use_texture_mode;
+        DeferredCommandDepthRange depth_range;
+        DeferredCommandApplyFog apply_fog;
+    };
+} DeferredCommand;
+
+#endif

src/rendering/twn_gl_15_rendering.c

@@ -4,6 +4,7 @@
 #include "twn_engine_context_c.h"
 #include "twn_text_c.h"
 #include "twn_types.h"
+#include "twn_deferred_commands.h"
 
 #include <glad/glad.h>
 #include <stb_ds.h>
@@ -76,107 +77,6 @@ typedef struct ElementIndexedQuadWithoutColorWithoutTexture {
 } ElementIndexedQuadWithoutColorWithoutTexture;
 
 
-typedef struct {
-    size_t offset;
-    GLenum type;
-    GLsizei stride;
-    GLuint buffer;
-    uint8_t arity; /* leave at 0 to signal pointer as unused */
-} AttributeArrayPointer;
-
-
-/* allows us to have generic way to issue draws as well as */
-/* deferring new draw calls while previous frame is still being drawn */
-typedef struct {
-    AttributeArrayPointer vertices;
-    AttributeArrayPointer texcoords;
-
-    bool constant_colored;
-    union {
-        AttributeArrayPointer colors;        
-        Color color;
-    };
-
-    bool textured, texture_repeat, uses_gpu_key;
-    TextureKey texture_key;
-    GPUTexture gpu_texture;
-
-    GLuint element_buffer;
-    GLsizei element_count;
-    GLsizei range_start, range_end;
-
-    /* could be either `element_count` with supplied `element_buffer`, or this, but not both */
-    GLsizei primitive_count;
-
-    double depth_range_low, depth_range_high;
-} DeferredCommandDraw;
-
-
-typedef struct {
-    char *paths;
-} DeferredCommandDrawSkybox;
-
-
-typedef struct {
-    Color color;
-    bool clear_color;
-    bool clear_depth;
-    bool clear_stencil;
-} DeferredCommandClear;
-
-
-typedef enum {
-    PIPELINE_NO,
-    PIPELINE_SPACE,
-    PIPELINE_2D,
-} Pipeline;
-
-
-typedef struct {
-    Pipeline pipeline;
-} DeferredCommandUsePipeline;
-
-
-typedef struct {
-    TextureMode mode;
-} DeferredCommandUseTextureMode;
-
-
-typedef struct {
-    double low, high;
-} DeferredCommandDepthRange;
-
-
-typedef struct {
-    float start, end, density;
-    Color color;
-} DeferredCommandApplyFog;
-
-
-typedef struct {
-    enum DeferredCommandType {
-        DEFERRED_COMMAND_TYPE_DRAW,
-        DEFERRED_COMMAND_TYPE_DRAW_SKYBOX,
-        DEFERRED_COMMAND_TYPE_CLEAR,
-        DEFERRED_COMMAND_TYPE_USE_PIPIELINE,
-        DEFERRED_COMMAND_TYPE_USE_TEXTURE_MODE,
-        DEFERRED_COMMAND_TYPE_DEPTH_RANGE,
-        DEFERRED_COMMAND_TYPE_APPLY_FOG,
-        DEFERRED_COMMAND_TYPE_POP_FOG,
-    } type;
-
-    union {
-        DeferredCommandDraw draw;
-        DeferredCommandDrawSkybox draw_skybox;
-        DeferredCommandClear clear;
-        DeferredCommandUsePipeline use_pipeline;
-        DeferredCommandUseTextureMode use_texture_mode;
-        DeferredCommandDepthRange depth_range;
-        DeferredCommandApplyFog apply_fog;
-    };
-} DeferredCommand;
-
-
 static TextureMode texture_mode_last_used = TEXTURE_MODE_UNKNOWN;
 static Pipeline pipeline_last_used = PIPELINE_NO;