SDL_gpu_OpenGL_1.h

#ifndef _SDL_GPU_OPENGL_1_H__
#define _SDL_GPU_OPENGL_1_H__

#include "SDL_gpu.h"

#if !defined(SDL_GPU_DISABLE_OPENGL) && !defined(SDL_GPU_DISABLE_OPENGL_1)

    // Hacks to fix compile errors due to polluted namespace
    #ifdef _WIN32
    #define _WINUSER_H
    #define _WINGDI_H
    #endif

    #include "glew.h"
    
    #if defined(GL_EXT_bgr) && !defined(GL_BGR)
        #define GL_BGR GL_BGR_EXT
    #endif
    #if defined(GL_EXT_bgra) && !defined(GL_BGRA)
        #define GL_BGRA GL_BGRA_EXT
    #endif
    #if defined(GL_EXT_abgr) && !defined(GL_ABGR)
        #define GL_ABGR GL_ABGR_EXT
    #endif
    
    #undef glBlendFuncSeparate
    #define glBlendFuncSeparate glBlendFuncSeparateEXT
    #undef glBlendEquation
    #define glBlendEquation glBlendEquationEXT
    #undef glBlendEquationSeparate
    #define glBlendEquationSeparate glBlendEquationSeparateEXT
    
    #undef GL_MIRRORED_REPEAT
    #define GL_MIRRORED_REPEAT GL_MIRRORED_REPEAT_ARB
    
    #undef glCreateShader
    #undef GL_VERTEX_SHADER
    #undef GL_FRAGMENT_SHADER
    #undef glShaderSource
    #undef glCompileShader
    #undef glGetShaderiv
    #undef GL_COMPILE_STATUS
    #undef glGetShaderInfoLog
    #undef glDeleteShader
    #undef glActiveTexture
    #undef GL_TEXTURE0
    #define glCreateShader glCreateShaderObjectARB
    #define GL_VERTEX_SHADER GL_VERTEX_SHADER_ARB
    #define GL_FRAGMENT_SHADER GL_FRAGMENT_SHADER_ARB
    #define glShaderSource glShaderSourceARB
    #define glCompileShader glCompileShaderARB
    #define glGetShaderiv glGetObjectParameterivARB
    #define GL_COMPILE_STATUS GL_OBJECT_COMPILE_STATUS_ARB
    #define glGetShaderInfoLog glGetInfoLogARB
    #define glDeleteShader glDeleteObjectARB
    #define glActiveTexture glActiveTextureARB
    #define GL_TEXTURE0 GL_TEXTURE0_ARB
    
    #undef glCreateProgram
    #undef glAttachShader
    #undef glLinkProgram
    #undef GL_LINK_STATUS
    #undef glGetProgramiv
    #undef glGetProgramInfoLog
    #undef glUseProgram
    #undef glDeleteProgram
    #define glCreateProgram glCreateProgramObjectARB
    #define glAttachShader glAttachObjectARB
    #define glLinkProgram glLinkProgramARB
    #define GL_LINK_STATUS GL_OBJECT_LINK_STATUS_ARB
    #define glGetProgramiv glGetObjectParameterivARB
    #define glGetProgramInfoLog glGetInfoLogARB
    #define glUseProgram glUseProgramObjectARB
    #define glDeleteProgram glDeleteObjectARB
    
    #undef glGetUniformLocation
    #undef glGetUniformiv
    #undef glUniform1i
    #undef glUniform1iv
    #undef glUniform2iv
    #undef glUniform3iv
    #undef glUniform4iv
    #undef glUniform1f
    #undef glUniform1fv
    #undef glUniform2fv
    #undef glUniform3fv
    #undef glUniform4fv
    #undef glUniformMatrix4fv
    #define glGetUniformLocation glGetUniformLocationARB
    #define glGetUniformiv glGetUniformivARB
    #define glUniform1i glUniform1iARB
    #define glUniform1iv glUniform1ivARB
    #define glUniform2iv glUniform2ivARB
    #define glUniform3iv glUniform3ivARB
    #define glUniform4iv glUniform4ivARB
    #define glUniform1f glUniform1fARB
    #define glUniform1fv glUniform1fvARB
    #define glUniform2fv glUniform2fvARB
    #define glUniform3fv glUniform3fvARB
    #define glUniform4fv glUniform4fvARB
    #define glUniformMatrix4fv glUniformMatrix4fvARB
    
    #undef glGetAttribLocation
    #undef glVertexAttrib1f
    #undef glVertexAttrib2f
    #undef glVertexAttrib3f
    #undef glVertexAttrib4f
    #undef glVertexAttribI1i
    #undef glVertexAttribI2i
    #undef glVertexAttribI3i
    #undef glVertexAttribI4i
    #undef glVertexAttribI1ui
    #undef glVertexAttribI2ui
    #undef glVertexAttribI3ui
    #undef glVertexAttribI4ui
    #define glGetAttribLocation glGetAttribLocationARB
    #define glVertexAttrib1f glVertexAttrib1fARB
    #define glVertexAttrib2f glVertexAttrib2fARB
    #define glVertexAttrib3f glVertexAttrib3fARB
    #define glVertexAttrib4f glVertexAttrib4fARB
    #define glVertexAttribI1i glVertexAttrib1sARB
    #define glVertexAttribI2i glVertexAttrib2sARB
    #define glVertexAttribI3i glVertexAttrib3sARB
    #define glVertexAttribI4i glVertexAttrib4sARB
    #define glVertexAttribI1ui glVertexAttrib1sARB
    #define glVertexAttribI2ui glVertexAttrib2sARB
    #define glVertexAttribI3ui glVertexAttrib3sARB
    #define glVertexAttribI4ui glVertexAttrib4sARB
    
    #undef glGenBuffers
    #undef glDeleteBuffers
    #undef glBindBuffer
    #undef glBufferData
    #undef glBufferSubData
    #undef GL_ARRAY_BUFFER
    #define glGenBuffers glGenBuffersARB
    #define glDeleteBuffers glDeleteBuffersARB
    #define glBindBuffer glBindBufferARB
    #define glBufferData glBufferDataARB
    #define glBufferSubData glBufferSubDataARB
    #define GL_ARRAY_BUFFER GL_ARRAY_BUFFER_ARB
    
    
    #undef glEnableVertexAttribArray
    #undef glDisableVertexAttribArray
    #undef glVertexAttribPointer
    #define glEnableVertexAttribArray glEnableVertexAttribArrayARB
    #define glDisableVertexAttribArray glDisableVertexAttribArrayARB
    #define glVertexAttribPointer glVertexAttribPointerARB
    
#endif



#define GPU_CONTEXT_DATA ContextData_OpenGL_1
#define GPU_IMAGE_DATA ImageData_OpenGL_1
#define GPU_TARGET_DATA TargetData_OpenGL_1




#define GPU_DEFAULT_TEXTURED_VERTEX_SHADER_SOURCE \
"#version 110\n\
\
attribute vec2 gpu_Vertex;\n\
attribute vec2 gpu_TexCoord;\n\
attribute vec4 gpu_Color;\n\
uniform mat4 gpu_ModelViewProjectionMatrix;\n\
\
varying vec4 color;\n\
varying vec2 texCoord;\n\
\
void main(void)\n\
{\n\
    color = gpu_Color;\n\
    texCoord = vec2(gpu_TexCoord);\n\
    gl_Position = gpu_ModelViewProjectionMatrix * vec4(gpu_Vertex, 0.0, 1.0);\n\
}"

// Tier 3 uses shader attributes to send position, texcoord, and color data for each vertex.
#define GPU_DEFAULT_UNTEXTURED_VERTEX_SHADER_SOURCE \
"#version 110\n\
\
attribute vec2 gpu_Vertex;\n\
attribute vec4 gpu_Color;\n\
uniform mat4 gpu_ModelViewProjectionMatrix;\n\
\
varying vec4 color;\n\
\
void main(void)\n\
{\n\
    color = gpu_Color;\n\
    gl_Position = gpu_ModelViewProjectionMatrix * vec4(gpu_Vertex, 0.0, 1.0);\n\
}"


#define GPU_DEFAULT_TEXTURED_FRAGMENT_SHADER_SOURCE \
"#version 110\n\
\
varying vec4 color;\n\
varying vec2 texCoord;\n\
\
uniform sampler2D tex;\n\
\
void main(void)\n\
{\n\
    gl_FragColor = texture2D(tex, texCoord) * color;\n\
}"

#define GPU_DEFAULT_UNTEXTURED_FRAGMENT_SHADER_SOURCE \
"#version 110\n\
\
varying vec4 color;\n\
\
void main(void)\n\
{\n\
    gl_FragColor = color;\n\
}"





typedef struct ContextData_OpenGL_1
{
    SDL_Color last_color;
    GPU_bool last_use_texturing;
    unsigned int last_shape;
    GPU_bool last_use_blending;
    GPU_BlendMode last_blend_mode;
    GPU_Rect last_viewport;
    GPU_Camera last_camera;
    GPU_bool last_camera_inverted;
    
    GPU_Image* last_image;
    GPU_Target* last_target;
    float* blit_buffer;  // Holds sets of 4 vertices and 4 tex coords interleaved (e.g. [x0, y0, z0, s0, t0, ...]).
    unsigned short blit_buffer_num_vertices;
    unsigned short blit_buffer_max_num_vertices;
    unsigned short* index_buffer;  // Indexes into the blit buffer so we can use 4 vertices for every 2 triangles (1 quad)
    unsigned int index_buffer_num_vertices;
    unsigned int index_buffer_max_num_vertices;
    
    
    unsigned int blit_VBO[2];  // For double-buffering
    unsigned int blit_IBO;
    GPU_bool blit_VBO_flop;
    
    GPU_AttributeSource shader_attributes[16];
    unsigned int attribute_VBO[16];
} ContextData_OpenGL_1;

typedef struct ImageData_OpenGL_1
{
    int refcount;
    GPU_bool owns_handle;
    Uint32 handle;
    Uint32 format;
} ImageData_OpenGL_1;

typedef struct TargetData_OpenGL_1
{
    int refcount;
    Uint32 handle;
    Uint32 format;
} TargetData_OpenGL_1;



#endif