tutorial16_SimpleVersion.cpp

// Include standard headers
#include <stdio.h>
#include <stdlib.h>
#include <vector>

// Include GLEW
#include <GL/glew.h>

// Include GLFW
#include <GLFW/glfw3.h>
GLFWwindow* window;

// Include GLM
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
using namespace glm;

#include <common/shader.hpp>
#include <common/texture.hpp>
#include <common/controls.hpp>
#include <common/objloader.hpp>
#include <common/vboindexer.hpp>

int main( void )
{
	// Initialise GLFW
	if( !glfwInit() )
	{
		fprintf( stderr, "Failed to initialize GLFW\n" );
		getchar();
		return -1;
	}

	glfwWindowHint(GLFW_SAMPLES, 4);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // To make MacOS happy; should not be needed
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

	// Open a window and create its OpenGL context
	window = glfwCreateWindow( 1024, 768, "Tutorial 16 - Shadows, Simple version", NULL, NULL);
	if( window == NULL ){
		fprintf( stderr, "Failed to open GLFW window. If you have an Intel GPU, they are not 3.3 compatible. Try the 2.1 version of the tutorials.\n" );
		getchar();
		glfwTerminate();
		return -1;
	}
	glfwMakeContextCurrent(window);
    
    // We would expect width and height to be 1024 and 768
    int windowWidth = 1024;
    int windowHeight = 768;
    // But on MacOS X with a retina screen it'll be 1024*2 and 768*2, so we get the acual framebuffer size:
    glfwGetFramebufferSize(window, &windowWidth, &windowHeight);

	// Initialize GLEW
	glewExperimental = true; // Needed for core profile
	if (glewInit() != GLEW_OK) {
		fprintf(stderr, "Failed to initialize GLEW\n");
		getchar();
		glfwTerminate();
		return -1;
	}

	// Ensure we can capture the escape key being pressed below
	glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);
    // Hide the mouse and enable unlimited mouvement
    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
    
    // Set the mouse at the center of the screen
    glfwPollEvents();
    glfwSetCursorPos(window, 1024/2, 768/2);

	// Dark blue background
	glClearColor(0.0f, 0.0f, 0.4f, 0.0f);

	// Enable depth test
	glEnable(GL_DEPTH_TEST);

	// Accept fragment if it closer to the camera than the former one
	glDepthFunc(GL_LESS); 

	// Cull triangles which normal is not towards the camera
	glEnable(GL_CULL_FACE);

	GLuint VertexArrayID;
	glGenVertexArrays(1, &VertexArrayID);
	glBindVertexArray(VertexArrayID);

	// Create and compile our GLSL program from the shaders
	GLuint depthProgramID = LoadShaders( "DepthRTT.vertexshader", "DepthRTT.fragmentshader" );

	// Get a handle for our "MVP" uniform
	GLuint depthMatrixID = glGetUniformLocation(depthProgramID, "depthMVP");

	// Load the texture
	GLuint Texture = loadDDS("uvmap.DDS");
	
	// Read our .obj file
	std::vector<glm::vec3> vertices;
	std::vector<glm::vec2> uvs;
	std::vector<glm::vec3> normals;
	bool res = loadOBJ("room_thickwalls.obj", vertices, uvs, normals);

	std::vector<unsigned short> indices;
	std::vector<glm::vec3> indexed_vertices;
	std::vector<glm::vec2> indexed_uvs;
	std::vector<glm::vec3> indexed_normals;
	indexVBO(vertices, uvs, normals, indices, indexed_vertices, indexed_uvs, indexed_normals);

	// Load it into a VBO

	GLuint vertexbuffer;
	glGenBuffers(1, &vertexbuffer);
	glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
	glBufferData(GL_ARRAY_BUFFER, indexed_vertices.size() * sizeof(glm::vec3), &indexed_vertices[0], GL_STATIC_DRAW);

	GLuint uvbuffer;
	glGenBuffers(1, &uvbuffer);
	glBindBuffer(GL_ARRAY_BUFFER, uvbuffer);
	glBufferData(GL_ARRAY_BUFFER, indexed_uvs.size() * sizeof(glm::vec2), &indexed_uvs[0], GL_STATIC_DRAW);

	GLuint normalbuffer;
	glGenBuffers(1, &normalbuffer);
	glBindBuffer(GL_ARRAY_BUFFER, normalbuffer);
	glBufferData(GL_ARRAY_BUFFER, indexed_normals.size() * sizeof(glm::vec3), &indexed_normals[0], GL_STATIC_DRAW);

	// Generate a buffer for the indices as well
	GLuint elementbuffer;
	glGenBuffers(1, &elementbuffer);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementbuffer);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(unsigned short), &indices[0], GL_STATIC_DRAW);


	// ---------------------------------------------
	// Render to Texture - specific code begins here
	// ---------------------------------------------

	// The framebuffer, which regroups 0, 1, or more textures, and 0 or 1 depth buffer.
	GLuint FramebufferName = 0;
	glGenFramebuffers(1, &FramebufferName);
	glBindFramebuffer(GL_FRAMEBUFFER, FramebufferName);

	// Depth texture. Slower than a depth buffer, but you can sample it later in your shader
	GLuint depthTexture;
	glGenTextures(1, &depthTexture);
	glBindTexture(GL_TEXTURE_2D, depthTexture);
	glTexImage2D(GL_TEXTURE_2D, 0,GL_DEPTH_COMPONENT16, 1024, 1024, 0,GL_DEPTH_COMPONENT, GL_FLOAT, 0);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); 
	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_COMPARE_FUNC, GL_LEQUAL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_R_TO_TEXTURE);
		 
	glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, depthTexture, 0);

	// No color output in the bound framebuffer, only depth.
	glDrawBuffer(GL_NONE);

	// Always check that our framebuffer is ok
	if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
		return false;

	// Create and compile our GLSL program from the shaders
	GLuint programID = LoadShaders( "ShadowMapping_SimpleVersion.vertexshader", "ShadowMapping_SimpleVersion.fragmentshader" );

	// Get a handle for our "myTextureSampler" uniform
	GLuint TextureID  = glGetUniformLocation(programID, "myTextureSampler");

	// Get a handle for our "MVP" uniform
	GLuint MatrixID = glGetUniformLocation(programID, "MVP");
	GLuint DepthBiasID = glGetUniformLocation(programID, "DepthBiasMVP");
	GLuint ShadowMapID = glGetUniformLocation(programID, "shadowMap");
		
	do{

		// Render to our framebuffer
		glBindFramebuffer(GL_FRAMEBUFFER, FramebufferName);
		glViewport(0,0,1024,1024); // Render on the whole framebuffer, complete from the lower left corner to the upper right

		// We don't use bias in the shader, but instead we draw back faces, 
		// which are already separated from the front faces by a small distance 
		// (if your geometry is made this way)
		glEnable(GL_CULL_FACE);
		glCullFace(GL_BACK); // Cull back-facing triangles -> draw only front-facing triangles

		// Clear the screen
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

		// Use our shader
		glUseProgram(depthProgramID);

		glm::vec3 lightInvDir = glm::vec3(0.5f,2,2);

		// Compute the MVP matrix from the light's point of view
		glm::mat4 depthProjectionMatrix = glm::ortho<float>(-10,10,-10,10,-10,20);
		glm::mat4 depthViewMatrix = glm::lookAt(lightInvDir, glm::vec3(0,0,0), glm::vec3(0,1,0));
		// or, for spot light :
		//glm::vec3 lightPos(5, 20, 20);
		//glm::mat4 depthProjectionMatrix = glm::perspective<float>(45.0f, 1.0f, 2.0f, 50.0f);
		//glm::mat4 depthViewMatrix = glm::lookAt(lightPos, lightPos-lightInvDir, glm::vec3(0,1,0));

		glm::mat4 depthModelMatrix = glm::mat4(1.0);
		glm::mat4 depthMVP = depthProjectionMatrix * depthViewMatrix * depthModelMatrix;

		// Send our transformation to the currently bound shader, 
		// in the "MVP" uniform
		glUniformMatrix4fv(depthMatrixID, 1, GL_FALSE, &depthMVP[0][0]);

		// 1rst attribute buffer : vertices
		glEnableVertexAttribArray(0);
		glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
		glVertexAttribPointer(
			0,  // The attribute we want to configure
			3,                  // size
			GL_FLOAT,           // type
			GL_FALSE,           // normalized?
			0,                  // stride
			(void*)0            // array buffer offset
		);

		// Index buffer
		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementbuffer);

		// Draw the triangles !
		glDrawElements(
			GL_TRIANGLES,      // mode
			indices.size(),    // count
			GL_UNSIGNED_SHORT, // type
			(void*)0           // element array buffer offset
		);

		glDisableVertexAttribArray(0);



		// Render to the screen
		glBindFramebuffer(GL_FRAMEBUFFER, 0);
		glViewport(0,0,windowWidth,windowHeight); // Render on the whole framebuffer, complete from the lower left corner to the upper right

		glEnable(GL_CULL_FACE);
		glCullFace(GL_BACK); // Cull back-facing triangles -> draw only front-facing triangles

		// Clear the screen
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

		// Use our shader
		glUseProgram(programID);

		// Compute the MVP matrix from keyboard and mouse input
		computeMatricesFromInputs();
		glm::mat4 ProjectionMatrix = getProjectionMatrix();
		glm::mat4 ViewMatrix = getViewMatrix();
		//ViewMatrix = glm::lookAt(glm::vec3(14,6,4), glm::vec3(0,1,0), glm::vec3(0,1,0));
		glm::mat4 ModelMatrix = glm::mat4(1.0);
		glm::mat4 MVP = ProjectionMatrix * ViewMatrix * ModelMatrix;
		
		glm::mat4 biasMatrix(
			0.5, 0.0, 0.0, 0.0, 
			0.0, 0.5, 0.0, 0.0,
			0.0, 0.0, 0.5, 0.0,
			0.5, 0.5, 0.5, 1.0
		);

		glm::mat4 depthBiasMVP = biasMatrix*depthMVP;

		// Send our transformation to the currently bound shader, 
		// in the "MVP" uniform
		glUniformMatrix4fv(MatrixID, 1, GL_FALSE, &MVP[0][0]);
		glUniformMatrix4fv(DepthBiasID, 1, GL_FALSE, &depthBiasMVP[0][0]);

		// Bind our texture in Texture Unit 0
		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, Texture);
		// Set our "myTextureSampler" sampler to use Texture Unit 0
		glUniform1i(TextureID, 0);

		glActiveTexture(GL_TEXTURE1);
		glBindTexture(GL_TEXTURE_2D, depthTexture);
		glUniform1i(ShadowMapID, 1);

		// 1rst attribute buffer : vertices
		glEnableVertexAttribArray(0);
		glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
		glVertexAttribPointer(
			0,                  // attribute
			3,                  // size
			GL_FLOAT,           // type
			GL_FALSE,           // normalized?
			0,                  // stride
			(void*)0            // array buffer offset
		);

		// 2nd attribute buffer : UVs
		glEnableVertexAttribArray(1);
		glBindBuffer(GL_ARRAY_BUFFER, uvbuffer);
		glVertexAttribPointer(
			1,                                // attribute
			2,                                // size
			GL_FLOAT,                         // type
			GL_FALSE,                         // normalized?
			0,                                // stride
			(void*)0                          // array buffer offset
		);

		// 3rd attribute buffer : normals
		glEnableVertexAttribArray(2);
		glBindBuffer(GL_ARRAY_BUFFER, normalbuffer);
		glVertexAttribPointer(
			2,                                // attribute
			3,                                // size
			GL_FLOAT,                         // type
			GL_FALSE,                         // normalized?
			0,                                // stride
			(void*)0                          // array buffer offset
		);

		// Index buffer
		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementbuffer);

		// Draw the triangles !
		glDrawElements(
			GL_TRIANGLES,      // mode
			indices.size(),    // count
			GL_UNSIGNED_SHORT, // type
			(void*)0           // element array buffer offset
		);

		glDisableVertexAttribArray(0);
		glDisableVertexAttribArray(1);
		glDisableVertexAttribArray(2);


		// Swap buffers
		glfwSwapBuffers(window);
		glfwPollEvents();

	} // Check if the ESC key was pressed or the window was closed
	while( glfwGetKey(window, GLFW_KEY_ESCAPE ) != GLFW_PRESS &&
		   glfwWindowShouldClose(window) == 0 );

	// Cleanup VBO and shader
	glDeleteBuffers(1, &vertexbuffer);
	glDeleteBuffers(1, &uvbuffer);
	glDeleteBuffers(1, &normalbuffer);
	glDeleteBuffers(1, &elementbuffer);
	glDeleteProgram(programID);
	glDeleteProgram(depthProgramID);
	glDeleteTextures(1, &Texture);

	glDeleteFramebuffers(1, &FramebufferName);
	glDeleteTextures(1, &depthTexture);


	// Close OpenGL window and terminate GLFW
	glfwTerminate();

	return 0;
}