// 
//---------------------------------------------------------------------------
//
// Copyright(C) 2014-2016 Christoph Oelckers
// All rights reserved.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program.  If not, see http://www.gnu.org/licenses/
//
//--------------------------------------------------------------------------
//

#include "gl/system/gl_system.h"
#include "templates.h"
#include "c_cvars.h"
#include "c_dispatch.h"

#include "gl/system/gl_interface.h"
#include "gl/system/gl_cvars.h"
#include "gl/system/gl_debug.h"
#include "gl/renderer/gl_renderer.h"
#include "gl_samplers.h"
#include "gl_material.h"

extern TexFilter_s TexFilter[];


FSamplerManager::FSamplerManager()
{
	if (gl.flags & RFL_SAMPLER_OBJECTS)
	{
		glGenSamplers(7, mSamplers);
		SetTextureFilterMode();
		glSamplerParameteri(mSamplers[5], GL_TEXTURE_MIN_FILTER, GL_NEAREST);
		glSamplerParameteri(mSamplers[5], GL_TEXTURE_MAG_FILTER, GL_NEAREST);
		glSamplerParameterf(mSamplers[5], GL_TEXTURE_MAX_ANISOTROPY_EXT, 1.f);
		glSamplerParameterf(mSamplers[4], GL_TEXTURE_MAX_ANISOTROPY_EXT, 1.f);
		glSamplerParameterf(mSamplers[6], GL_TEXTURE_MAX_ANISOTROPY_EXT, 1.f);

		glSamplerParameteri(mSamplers[1], GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		glSamplerParameteri(mSamplers[2], GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
		glSamplerParameteri(mSamplers[3], GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		glSamplerParameteri(mSamplers[3], GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
		glSamplerParameteri(mSamplers[4], GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		glSamplerParameteri(mSamplers[4], GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

		for (int i = 0; i < 7; i++)
		{
			FString name;
			name.Format("mSamplers[%d]", i);
			FGLDebug::LabelObject(GL_SAMPLER, mSamplers[i], name);
		}
	}

}

FSamplerManager::~FSamplerManager()
{
	if (gl.flags & RFL_SAMPLER_OBJECTS)
	{
		UnbindAll();
		glDeleteSamplers(7, mSamplers);
	}
}

void FSamplerManager::UnbindAll()
{
	if (gl.flags & RFL_SAMPLER_OBJECTS)
	{
		for (int i = 0; i < FHardwareTexture::MAX_TEXTURES; i++)
		{
			glBindSampler(i, 0);
		}
	}
}
	
BYTE FSamplerManager::Bind(int texunit, int num, int lastval)
{
	if (gl.flags & RFL_SAMPLER_OBJECTS)
	{
		unsigned int samp = mSamplers[num];
		glBindSampler(texunit, samp);
		return 255;
	}
	else
	{
		glActiveTexture(GL_TEXTURE0 + texunit);
		switch (num)
		{
		case CLAMP_NONE:
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
			if (lastval >= CLAMP_XY_NOMIP)
			{
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, TexFilter[gl_texture_filter].minfilter);
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, TexFilter[gl_texture_filter].magfilter);
				glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, gl_texture_filter_anisotropic);
			}
			break;

		case CLAMP_X:
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
			if (lastval >= CLAMP_XY_NOMIP)
			{
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, TexFilter[gl_texture_filter].minfilter);
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, TexFilter[gl_texture_filter].magfilter);
				glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, gl_texture_filter_anisotropic);
			}
			break;

		case CLAMP_Y:
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
			if (lastval >= CLAMP_XY_NOMIP)
			{
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, TexFilter[gl_texture_filter].minfilter);
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, TexFilter[gl_texture_filter].magfilter);
				glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, gl_texture_filter_anisotropic);
			}
			break;

		case CLAMP_XY:
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
			if (lastval >= CLAMP_XY_NOMIP)
			{
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, TexFilter[gl_texture_filter].minfilter);
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, TexFilter[gl_texture_filter].magfilter);
				glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, gl_texture_filter_anisotropic);
			}
			break;

		case CLAMP_XY_NOMIP:
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, TexFilter[gl_texture_filter].magfilter);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, TexFilter[gl_texture_filter].magfilter);
			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 1);
			break;

		case CLAMP_NOFILTER:
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 1);
			break;

		case CLAMP_CAMTEX:
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, TexFilter[gl_texture_filter].magfilter);
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, TexFilter[gl_texture_filter].magfilter);
			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 1);
			break;
		}
		glActiveTexture(GL_TEXTURE0);
		return num;
	}
}

	
void FSamplerManager::SetTextureFilterMode()
{
	if (gl.flags & RFL_SAMPLER_OBJECTS)
	{
		UnbindAll();

		for (int i = 0; i < 4; i++)
		{
			glSamplerParameteri(mSamplers[i], GL_TEXTURE_MIN_FILTER, TexFilter[gl_texture_filter].minfilter);
			glSamplerParameteri(mSamplers[i], GL_TEXTURE_MAG_FILTER, TexFilter[gl_texture_filter].magfilter);
			glSamplerParameterf(mSamplers[i], GL_TEXTURE_MAX_ANISOTROPY_EXT, gl_texture_filter_anisotropic);
		}
		glSamplerParameteri(mSamplers[4], GL_TEXTURE_MIN_FILTER, TexFilter[gl_texture_filter].magfilter);
		glSamplerParameteri(mSamplers[4], GL_TEXTURE_MAG_FILTER, TexFilter[gl_texture_filter].magfilter);
		glSamplerParameteri(mSamplers[6], GL_TEXTURE_MIN_FILTER, TexFilter[gl_texture_filter].magfilter);
		glSamplerParameteri(mSamplers[6], GL_TEXTURE_MAG_FILTER, TexFilter[gl_texture_filter].magfilter);
	}
	else
	{
		GLRenderer->FlushTextures();
	}
}