/*
 * This file is part of the Colobot: Gold Edition source code
 * Copyright (C) 2001-2014, Daniel Roux, EPSITEC SA & TerranovaTeam
 * http://epsiteс.ch; http://colobot.info; http://github.com/colobot
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see http://gnu.org/licenses
 */

#include "graphics/opengl/glutil.h"
#include "graphics/core/device.h"

#include "GL/glew.h"

// Graphics module namespace
namespace Gfx {

GLDeviceConfig::GLDeviceConfig()
{
    LoadDefault();
}

GLuint textureCoordinates[] = { GL_S, GL_T, GL_R, GL_Q };
GLuint textureCoordGen[] = { GL_TEXTURE_GEN_S, GL_TEXTURE_GEN_T, GL_TEXTURE_GEN_R, GL_TEXTURE_GEN_Q };

void GLDeviceConfig::LoadDefault()
{
    DeviceConfig::LoadDefault();

    hardwareAccel = true;

    redSize = 8;
    blueSize = 8;
    greenSize = 8;
    alphaSize = 8;
    depthSize = 24;

    vboMode = VBO_MODE_AUTO;
}

GLenum TranslateGfxPrimitive(PrimitiveType type)
{
    GLenum flag = 0;
    switch (type)
    {
    case PRIMITIVE_POINTS:         flag = GL_POINTS; break;
    case PRIMITIVE_LINES:          flag = GL_LINES; break;
    case PRIMITIVE_LINE_STRIP:     flag = GL_LINE_STRIP; break;
    case PRIMITIVE_TRIANGLES:      flag = GL_TRIANGLES; break;
    case PRIMITIVE_TRIANGLE_STRIP: flag = GL_TRIANGLE_STRIP; break;
    default: assert(false); break;
    }
    return flag;
}

CompFunc TranslateGLCompFunc(GLenum flag)
{
    switch (flag)
    {
    case GL_NEVER:    return COMP_FUNC_NEVER;
    case GL_LESS:     return COMP_FUNC_LESS;
    case GL_EQUAL:    return COMP_FUNC_EQUAL;
    case GL_NOTEQUAL: return COMP_FUNC_NOTEQUAL;
    case GL_LEQUAL:   return COMP_FUNC_LEQUAL;
    case GL_GREATER:  return COMP_FUNC_GREATER;
    case GL_GEQUAL:   return COMP_FUNC_GEQUAL;
    case GL_ALWAYS:   return COMP_FUNC_ALWAYS;
    default: assert(false); break;
    }
    return COMP_FUNC_NEVER;
}

GLenum TranslateGfxCompFunc(CompFunc func)
{
    switch (func)
    {
    case COMP_FUNC_NEVER:    return GL_NEVER;
    case COMP_FUNC_LESS:     return GL_LESS;
    case COMP_FUNC_EQUAL:    return GL_EQUAL;
    case COMP_FUNC_NOTEQUAL: return GL_NOTEQUAL;
    case COMP_FUNC_LEQUAL:   return GL_LEQUAL;
    case COMP_FUNC_GREATER:  return GL_GREATER;
    case COMP_FUNC_GEQUAL:   return GL_GEQUAL;
    case COMP_FUNC_ALWAYS:   return GL_ALWAYS;
    default: assert(false); break;
    }
    return 0;
}

BlendFunc TranslateGLBlendFunc(GLenum flag)
{
    switch (flag)
    {
    case GL_ZERO:                return BLEND_ZERO;
    case GL_ONE:                 return BLEND_ONE;
    case GL_SRC_COLOR:           return BLEND_SRC_COLOR;
    case GL_ONE_MINUS_SRC_COLOR: return BLEND_INV_SRC_COLOR;
    case GL_DST_COLOR:           return BLEND_DST_COLOR;
    case GL_ONE_MINUS_DST_COLOR: return BLEND_INV_DST_COLOR;
    case GL_SRC_ALPHA:           return BLEND_SRC_ALPHA;
    case GL_ONE_MINUS_SRC_ALPHA: return BLEND_INV_SRC_ALPHA;
    case GL_DST_ALPHA:           return BLEND_DST_ALPHA;
    case GL_ONE_MINUS_DST_ALPHA: return BLEND_INV_DST_ALPHA;
    case GL_SRC_ALPHA_SATURATE:  return BLEND_SRC_ALPHA_SATURATE;
    default: assert(false); break;
    }

    return BLEND_ZERO;
}

GLenum TranslateGfxBlendFunc(BlendFunc func)
{
    switch (func)
    {
    case BLEND_ZERO:               return GL_ZERO;
    case BLEND_ONE:                return GL_ONE;
    case BLEND_SRC_COLOR:          return GL_SRC_COLOR;
    case BLEND_INV_SRC_COLOR:      return GL_ONE_MINUS_SRC_COLOR;
    case BLEND_DST_COLOR:          return GL_DST_COLOR;
    case BLEND_INV_DST_COLOR:      return GL_ONE_MINUS_DST_COLOR;
    case BLEND_SRC_ALPHA:          return GL_SRC_ALPHA;
    case BLEND_INV_SRC_ALPHA:      return GL_ONE_MINUS_SRC_ALPHA;
    case BLEND_DST_ALPHA:          return GL_DST_ALPHA;
    case BLEND_INV_DST_ALPHA:      return GL_ONE_MINUS_DST_ALPHA;
    case BLEND_SRC_ALPHA_SATURATE: return GL_SRC_ALPHA_SATURATE;
    default: assert(false); break;
    }
    return 0;
}

bool InPlane(Math::Vector normal, float originPlane, Math::Vector center, float radius)
{
    float distance = originPlane + Math::DotProduct(normal, center);

    if (distance < -radius)
        return false;

    return true;
}

}