#include "Renderer.h"
const int POST_PASSES = 10;
Renderer::Renderer(Window& parent) : OGLRenderer(parent) {
	camera = new Camera(-25.0f, 225.0f,
		Vector3(-150.0f, 250.0f, -150.0f));

	quad = Mesh::GenerateQuad();

	heightMap = new HeightMap(TEXTUREDIR"noise.png");
	heightTexture = SOIL_load_OGL_texture(TEXTUREDIR"Barren Reds.JPG",
		SOIL_LOAD_AUTO, SOIL_CREATE_NEW_ID, SOIL_FLAG_MIPMAPS);

	sceneShader = new Shader("TexturedVertex.glsl",
		"TexturedFragment.glsl");
	processShader = new Shader("TexturedVertex.glsl",
		"processfrag.glsl");

	if (!processShader->LoadSuccess() || !sceneShader->LoadSuccess()) {
		return;
	}

	SetTextureRepeating(heightTexture, true);

	//Generate our scene depth texture
	glGenTextures(1, &bufferDepthTex);
	glBindTexture(GL_TEXTURE_2D, bufferDepthTex);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH24_STENCIL8, width, height,
		0, GL_DEPTH_STENCIL, GL_UNSIGNED_INT_24_8, NULL);

	// And our colour texture ...
	for (int i = 0; i < 2; ++i) {
	 glGenTextures(1, &bufferColourTex[i]);
	 glBindTexture(GL_TEXTURE_2D, bufferColourTex[i]);
	 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
	 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
	 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0,
	 GL_RGBA, GL_UNSIGNED_BYTE, NULL);	
	}

	glGenFramebuffers(1, &bufferFBO);
	glGenFramebuffers(1, &processFBO);

	glBindFramebuffer(GL_FRAMEBUFFER, bufferFBO);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
		GL_TEXTURE_2D, bufferDepthTex, 0);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
		GL_TEXTURE_2D, bufferDepthTex, 0);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
		GL_TEXTURE_2D, bufferColourTex[0], 0);
	//We can check FBO attachment success using this command!
	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) !=
		GL_FRAMEBUFFER_COMPLETE || !bufferDepthTex || !bufferColourTex[0]) {
		return;
	}

	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glEnable(GL_DEPTH_TEST);
	init = true;
}

Renderer::~Renderer(void) {
	delete sceneShader;
	delete processShader;
	delete heightMap;
	delete quad;
	delete camera;

	glDeleteTextures(2, bufferColourTex);
	glDeleteTextures(1, &bufferDepthTex);
	glDeleteFramebuffers(1, &bufferFBO);
	glDeleteFramebuffers(1, &processFBO);
}

void Renderer::UpdateScene(float dt) {
	camera->UpdateCamera(dt);
	viewMatrix = camera->BuildViewMatrix();
}

void Renderer::RenderScene() {
	DrawScene();
	DrawPostProcess();
	PresentScene();
}

void Renderer::DrawScene() {
	glBindFramebuffer(GL_FRAMEBUFFER, bufferFBO);
	glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT |
		GL_STENCIL_BUFFER_BIT);

	BindShader(sceneShader);
	projMatrix = Matrix4::Perspective(1.0f, 10000.0f,
		(float)width / (float)height, 45.0f);

	UpdateShaderMatrices();
	glUniform1i(glGetUniformLocation(sceneShader->GetProgram(), "diffuseTex"), 0);
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D, heightTexture);
	heightMap->Draw();
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

void Renderer::DrawPostProcess() {
	glBindFramebuffer(GL_FRAMEBUFFER, processFBO);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
		GL_TEXTURE_2D, bufferColourTex[1], 0);
	
	glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);

	BindShader(processShader);
	modelMatrix.ToIdentity();
	viewMatrix.ToIdentity();
	projMatrix.ToIdentity();
	UpdateShaderMatrices();

	glDisable(GL_DEPTH_TEST);

	glActiveTexture(GL_TEXTURE0);
	glUniform1i(glGetUniformLocation(
		processShader->GetProgram(), "sceneTex"), 0);
	for (int i = 0; i < POST_PASSES; ++i) {
		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
			GL_TEXTURE_2D, bufferColourTex[1], 0);
		glUniform1i(glGetUniformLocation(processShader->GetProgram(),
			"isVertical"), 0);

		glBindTexture(GL_TEXTURE_2D, bufferColourTex[0]);
		quad->Draw();
		//Now to swap the colour buffers, and do the second blur pass
		glUniform1i(glGetUniformLocation(processShader->GetProgram(),
			"isVertical"), 1);

		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
			GL_TEXTURE_2D, bufferColourTex[0], 0);
		glBindTexture(GL_TEXTURE_2D, bufferColourTex[1]);
		quad->Draw();
	}
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glEnable(GL_DEPTH_TEST);
}

void Renderer::PresentScene() {
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
	BindShader(sceneShader);
	modelMatrix.ToIdentity();
	viewMatrix.ToIdentity();
	projMatrix.ToIdentity();
	UpdateShaderMatrices();
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D, bufferColourTex[0]);
	glUniform1i(glGetUniformLocation(
		sceneShader->GetProgram(), "diffuseTex"), 0);
	quad->Draw();
}