1 files changed, 117 insertions, 0 deletions
diff --git a/src/render/gl.h b/src/render/gl.h
new file mode 100644
index 0000000..cf2b5dd
--- /dev/null
+++ b/src/render/gl.h
@@ -0,0 +1,117 @@
+#pragma once
+
+#include <SDL.h>
+#include <GLES2/gl2.h>
+
+#include "../util.h"
+#include "../util/matrix.h"
+
+typedef struct GL_FONT *PGL_FONT;
+typedef struct GL_DATA *PGL_DATA;
+
+struct VERTEX {
+  VEC2 pos;
+  VEC2 uv;
+  CLR clr;
+  U8 sampler;
+};
+
+struct GL_SHADER_DEF {
+  const char* name;
+  const char* code;
+  I32         type;
+  U32         id;
+  U8          compiled;
+};
+
+struct GL_SHADER_PROGRAM {
+  const char* name;
+  GL_SHADER_DEF fsh;
+  GL_SHADER_DEF vsh;
+  U32 id;
+  U32 vbuffer;
+
+  GL_DATA* gl;
+};
+
+struct GL_TEX2D {
+  GLuint id;
+  char name[256];
+  U32 width;
+  U32 height;
+  U32 channels;
+  U8* data;
+};
+
+typedef struct GL_DATA {
+  SDL_Window*   window;
+  SDL_GLContext ctx;
+  SDL_Renderer* renderer;
+
+  I32 canvas_size[2];
+
+  LIST<GL_SHADER_PROGRAM*> programs;
+  LIST<GL_TEX2D*>   textures;
+  LIST<GL_FONT*>    fonts;
+
+  I32 shader_texture_limit;
+  U64 last_tick;
+  F32 frametime;
+  F32 fps;
+
+  GLuint vbuffer;
+
+  VEC2 clip_start;
+  VEC2 clip_dim;
+
+  VEC2 viewport_start;
+  VEC2 viewport_dim;
+
+  MAT4* proj_matrix;
+} *PGL_DATA;
+
+GL_DATA*    gl_instance();
+GL_DATA*    gl_create( I32* _canvas );
+void        gl_destroy( GL_DATA* gl );
+void        gl_gen_buffers( GL_DATA* gl );
+STAT        gl_beginframe( GL_DATA* gl );
+STAT        gl_endframe( GL_DATA* gl );
+STAT        gl_shader_compile( GL_DATA* gl, GL_SHADER_DEF* shader );
+void        gl_shader_destroy( GL_DATA* gl, GL_SHADER_DEF* shader );
+GL_SHADER_PROGRAM* gl_program_create( GL_DATA* gl, const char* name, U32 size = sizeof(GL_SHADER_PROGRAM) );
+STAT        gl_program_compile( GL_DATA* gl, GL_SHADER_PROGRAM* program );
+void        gl_program_destroy( GL_DATA* gl, GL_SHADER_PROGRAM* program );
+GL_TEX2D*   gl_texture_create( GL_DATA* gl, const char* name );
+GL_TEX2D*   gl_texture_from_file( GL_DATA* gl, const char* name );
+GL_TEX2D*   gl_texture_from_bitmap( GL_DATA* gl, const char* name, U8* bitmap, U32 width, U32 height );
+void        gl_texture_destroy( GL_DATA* gl, GL_TEX2D* tex );
+void        gl_update_window( GL_DATA* gl, I32* size );
+void        gl_set_clip( GL_DATA* gl, VEC2 start, VEC2 dim );
+void        gl_get_clip( GL_DATA* gl, VEC2* start, VEC2* dim );
+void        gl_set_viewport( GL_DATA* gl, VEC2 start, VEC2 dim );
+void        gl_get_viewport( GL_DATA* gl, VEC2* start, VEC2* dim );
+void        gl_reset_clip( GL_DATA* gl );
+
+// special sampler id for no texture
+const  U8  SAMPLER_ID_NONE = 255;
+extern I32 SAMPLER_INDICES[255];
+
+template <typename VERTEX>
+LIST<VERTEX> triangle_fan_to_list( VERTEX* vertices, U32 vert_count ) {
+  LIST<VERTEX> ret{};
+  if( vert_count < 3 ) {
+    return ret;
+  }
+
+  ret.reserve( (vert_count - 2) * 3 );
+  VERTEX* start = &vertices[0];
+  VERTEX* last = &vertices[1];
+  for( U32 i = 2; i < vert_count; ++i ) {
+    ret.push( *start );
+    ret.push( *last );
+    ret.push( vertices[i] );
+    last = &vertices[i];
+  }
+
+  return ret;
+}