#include "rendertarget_fbo.h"

using namespace std;

static GLenum samp_mode[]=
{
	GL_LINEAR,
	GL_NEAREST,
	GL_LINEAR_MIPMAP_LINEAR
};

static GLenum wrap_mode[]=
{
	GL_REPEAT,
	GL_CLAMP,
	GL_CLAMP_TO_EDGE
};

// some of the FBO create code is from the NVIDIA SDK OpenGL stuff
static bool CheckFramebufferStatus( bool silent = false)
{
    GLenum status;
    status = (GLenum) glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
    switch(status) {
        case GL_FRAMEBUFFER_COMPLETE_EXT:
            break;
        case GL_FRAMEBUFFER_UNSUPPORTED_EXT:
            if (!silent) printf("Unsupported framebuffer format\n");
            return false;
        case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT_EXT:
            if (!silent) printf("Framebuffer incomplete, missing attachment\n");
            return false;
        case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT:
            if (!silent) printf("Framebuffer incomplete, duplicate attachment\n");
            return false;
        case GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT:
            if (!silent) printf("Framebuffer incomplete, attached images must have same dimensions\n");
            return false;
        case GL_FRAMEBUFFER_INCOMPLETE_FORMATS_EXT:
            if (!silent) printf("Framebuffer incomplete, attached images must have same format\n");
            return false;
        case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER_EXT:
            if (!silent) printf("Framebuffer incomplete, missing draw buffer\n");
            return false;
        case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER_EXT:
            if (!silent) printf("Framebuffer incomplete, missing read buffer\n");
            return false;
        default:
            return false;
    }
    return true;
}

RenderTargetFBO::RenderTargetFBO(SamplerState samp,int po2lev,bool floatformat):
	po2lev(po2lev), RenderTarget((float)(1<<po2lev),(float)(1<<po2lev)), Texture()
{
	is_main_fb=false;
	is_floating_point=floatformat;

	if (!GLEE_EXT_framebuffer_object)
	{
		is_valid=false;
		return;
	}

	bool floatsupport=GLEE_ARB_texture_float!=0;
	if (!floatsupport) floatformat=is_floating_point=false;

	glGenFramebuffersEXT(1,&fb);
	//glGenRenderbuffersEXT(1,&colorrb);
	glGenRenderbuffersEXT(1,&depthrb);

    glGenTextures(1,&colortex);

    glBindTexture(GL_TEXTURE_2D,colortex);
	if (floatsupport&&floatformat)
	{
		glTexImage2D(GL_TEXTURE_2D,0,GL_RGB16F_ARB,
			1<<po2lev,1<<po2lev,0,GL_RGBA,GL_FLOAT,NULL);
		is_floating_point=true;
	}
	else
	{
		glTexImage2D(GL_TEXTURE_2D,0,GL_RGB8,
			1<<po2lev,1<<po2lev,0,GL_RGBA,GL_FLOAT,NULL);
		is_floating_point=false;
	}

	if (samp.minmode==RAVEN_MIPMAP_SAMPLE) samp.minmode=RAVEN_LINEAR_SAMPLE;

	if (samp.aniso&&GLEE_EXT_texture_filter_anisotropic)
		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAX_ANISOTROPY_EXT,samp.aniso);
    
	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP);
	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP);

	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,samp_mode[samp.magmode]);
	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,samp_mode[samp.minmode]);

	glTexParameteri(GL_TEXTURE_2D,GL_GENERATE_MIPMAP,GL_TRUE);

	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,fb); 
	glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,GL_COLOR_ATTACHMENT0_EXT,GL_TEXTURE_2D,colortex,0);

	/*glBindRenderbufferEXT(GL_RENDERBUFFER_EXT,colorrb);
	glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT,(floatsupport&&floatformat)?GL_RGBA16F_ARB:GL_RGBA8,1<<po2lev,1<<po2lev);
	glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,GL_COLOR_ATTACHMENT0_EXT,GL_RENDERBUFFER_EXT,colorrb);*/

	/*glGenTextures(1,&depthtex);

	glBindTexture(GL_TEXTURE_2D,depthtex);
	glTexImage2D(GL_TEXTURE_2D,0,GL_DEPTH_COMPONENT16,
		1<<po2lev,1<<po2lev,0,GL_DEPTH_COMPONENT,GL_FLOAT,NULL);

	if (samp.minmode==RAVEN_MIPMAP_SAMPLE) samp.minmode=RAVEN_LINEAR_SAMPLE;

	if (samp.aniso&&GLEE_EXT_texture_filter_anisotropic)
		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAX_ANISOTROPY_EXT,samp.aniso);

	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,samp_mode[samp.minmode]);
	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP);
	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP);
	glTexParameteri(GL_TEXTURE_2D,GL_DEPTH_TEXTURE_MODE,GL_LUMINANCE);

	glTexParameteri(GL_TEXTURE_2D,GL_GENERATE_MIPMAP,GL_TRUE);

	glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,GL_DEPTH_ATTACHMENT_EXT,GL_TEXTURE_2D,depthtex,0);*/

	glBindRenderbufferEXT(GL_RENDERBUFFER_EXT,depthrb);
	glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT,GL_DEPTH_COMPONENT16,1<<po2lev,1<<po2lev);
	glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,GL_DEPTH_ATTACHMENT_EXT,GL_RENDERBUFFER_EXT,depthrb);

	if (!CheckFramebufferStatus(false)) is_valid=false;

	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,0);
	//glBindRenderbufferEXT(GL_RENDERBUFFER_EXT,0);
}

RenderTargetFBO::~RenderTargetFBO()
{
	//glDeleteRenderbuffersEXT(1,&colorrb);
	glDeleteRenderbuffersEXT(1,&depthrb);
	glDeleteTextures(1,&colortex);
	//glDeleteTextures(1,&depthtex);
	glDeleteFramebuffersEXT(1,&fb);
}

bool RenderTargetFBO::BindTarget()
{
	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,fb);
	glViewport(0,0,1<<po2lev,1<<po2lev);
	return true;
}

void RenderTargetFBO::Bind(int stage)
{
	if (bindmode!=RAVEN_TEXTURE_BIND_NONE)
	{
		glActiveTextureARB(GL_TEXTURE0+stage);
		glBindTexture(GL_TEXTURE_2D,colortex);

		glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_MODULATE);

		glTexEnvi(GL_TEXTURE_ENV,GL_COMBINE_RGB,GL_MODULATE);
		glTexEnvi(GL_TEXTURE_ENV,GL_SRC1_RGB,GL_PREVIOUS);
		glTexEnvi(GL_TEXTURE_ENV,GL_SRC2_RGB,GL_TEXTURE);

		glTexEnvi(GL_TEXTURE_ENV,GL_COMBINE_ALPHA,GL_MODULATE);
		glTexEnvi(GL_TEXTURE_ENV,GL_SRC1_ALPHA,GL_PREVIOUS);
		glTexEnvi(GL_TEXTURE_ENV,GL_SRC2_ALPHA,GL_TEXTURE);
	}
}