void setup_vertex_normal_buffer_object(bool smoothed) {
std::vector<glm::vec3> vertices = trig.Vertices();
std::vector<glm::vec3> normals;
if (smoothed) {
// initialize map of normals to zero
// note that we store readily hashable vector<double> types instead of
// vec3s and convert between the two as required
// ...avoids some of the pain using <map> without much C++ knowledge
std::map< std::vector<double>, std::vector<double> > normal_map;
for (int i = 0; i < vertices.size(); i++) {
std::vector<double> zeros;
zeros.push_back(0.0);
zeros.push_back(0.0);
zeros.push_back(0.0);
normal_map[to_vector(vertices[i])] = zeros;
}
for (int i = 0; i < vertices.size(); i += 3) {
// get vertices of the current triangle
glm::vec3 v1 = vertices[i];
glm::vec3 v2 = vertices[i + 1];
glm::vec3 v3 = vertices[i + 2];
std::vector<double> v1_key = to_vector(v1);
std::vector<double> v2_key = to_vector(v2);
std::vector<double> v3_key = to_vector(v3);
// compute face normal
glm::vec3 face_normal = glm::cross(v3 - v2, v1 - v2);
// get the old vertex normal
glm::vec3 v1_old = to_vec3(normal_map[v1_key]);
glm::vec3 v2_old = to_vec3(normal_map[v2_key]);
glm::vec3 v3_old = to_vec3(normal_map[v3_key]);
// replace the old value with the new value
normal_map.erase(v1_key);
normal_map.erase(v2_key);
normal_map.erase(v3_key);
normal_map[v1_key] = to_vector(glm::normalize(v1_old + face_normal));
normal_map[v2_key] = to_vector(glm::normalize(v2_old + face_normal));
normal_map[v3_key] = to_vector(glm::normalize(v3_old + face_normal));
}
// convert the map of normals to a vector of normals
for (int i = 0; i < vertices.size(); i++) {
normals.push_back(to_vec3(normal_map[to_vector(vertices[i])]));
}
} else {
for (int i = 0; i < vertices.size(); i += 3) {
// get vertices of this triangle
glm::vec3 v1 = vertices[i];
glm::vec3 v2 = vertices[i + 1];
glm::vec3 v3 = vertices[i + 2];
// compute face normal
glm::vec3 face_normal = glm::cross(v3 - v2, v1 - v2);
normals.push_back(glm::normalize(face_normal));
normals.push_back(glm::normalize(face_normal));
normals.push_back(glm::normalize(face_normal));
}
}
glGenBuffers(1, &vertex_normal_buffer);
glBindBuffer(GL_ARRAY_BUFFER, vertex_normal_buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(glm::vec3) * normals.size(),
&normals[0], GL_STATIC_DRAW);
}
//Program entry point.
//argc is a count of the number of arguments (including the filename of the program).
//argv is a pointer to each c-style string.
int main(int argc, char **argv)
{
atexit(cleanup);
cout << "Computer Graphics Assignment 1 Demo Program" << endl;
if (argc > 1)
{
geom.LoadFile(argv[1]);
}
else
{
cerr << "Usage:" << endl;
cerr << argv[0] << " <filename> " << endl;
exit(1);
}
geom.CalculateNormals();
//initialise OpenGL
GLFWwindow* window = initialiseGL();
//create framebuffers
glGenFramebuffers(1, &frameBuffer);
glBindFramebuffer(GL_FRAMEBUFFER, frameBuffer);
renderTarget = setupTextureGL(NULL, 800, 600, GL_RGBA);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, renderTarget, 0);
//depth/stencil buffer
glGenTextures(1, &depthStencil);
glBindTexture(GL_TEXTURE_2D, depthStencil);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH24_STENCIL8, 800, 600, 0, GL_DEPTH_STENCIL, GL_UNSIGNED_INT_24_8, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_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);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_TEXTURE_2D, depthStencil, 0);
GLenum err = GL_NO_ERROR;
while ((err = glGetError()) != GL_NO_ERROR)
{
printf("%d\n", err);
}
//load and compile the shaders
GLuint objectVertexShader = loadVertexShaderGL("vertex.glsl");
GLuint objectFragmentShader = loadFragmentShaderGL("fragment.glsl");
objectShaderProgram = makeShaderProgramGL(objectVertexShader, objectFragmentShader);
GLuint screenVertexShader = loadVertexShaderGL("postvertex.glsl");
GLuint screenFragmentShader = loadFragmentShaderGL("postfragment.glsl");
screenShaderProgram = makeShaderProgramGL(screenVertexShader, screenFragmentShader);
//transfer the geometry to the GPU
glGenVertexArrays(1, &objectVertexArray);
glBindVertexArray(objectVertexArray);
//create buffers we will use
glGenBuffers(1, &objectVertexBuffer);
glGenBuffers(1, &objectElementBuffer);
glGenBuffers(1, &objectNormBuffer);
//get geometry vertices, normals and edge lists
vector <glm::vec3> vert = geom.Vertices();
vector <glm::vec3> norm = geom.Norms();
//vector <glm::vec2> uv=geom.UVs();
vector <Triangle> tri = geom.Triangles();
//transfer to GPU
//data for each vertex
glBindBuffer(GL_ARRAY_BUFFER, objectVertexBuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 3 * vert.size(), &vert[0], GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, objectNormBuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 3 * norm.size(), &norm[0], GL_STATIC_DRAW);
//element array (triangles)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, objectElementBuffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, tri.size() * 3 * sizeof(unsigned int), &tri[0], GL_STATIC_DRAW);
//setup for postprocessing
glGenVertexArrays(1, &screenVertexArray);
glBindVertexArray(screenVertexArray);
//create buffers we will use
glGenBuffers(1, &screenVertexBuffer);
glGenBuffers(1, &screenElementBuffer);
//data for each vertex
glBindBuffer(GL_ARRAY_BUFFER, screenVertexBuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 2 * 4, &screenVertex[0], GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, screenElementBuffer);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, 2 * 3 * sizeof(GLuint), &screenTri[0], GL_STATIC_DRAW);
//load the texture
readTexture();
texture = setupTextureGL(tex, 256, 256, GL_RGB);
//main loop
while (!glfwWindowShouldClose(window))
{
DemoDisplay();
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwTerminate();
}
void setup_vertex_position_buffer_object(void) {
glGenBuffers(1, &vertex_position_buffer);
glBindBuffer(GL_ARRAY_BUFFER, vertex_position_buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(glm::vec3) * trig.VertexCount(),
&trig.Vertices()[0], GL_STATIC_DRAW);
}
