//
// load a simple vertex shader + fragment shader pair from files
// and compile+link it into a new shader program
// returns handle to program
GLuint link_programme_from_files (const char* vs_file_name,
const char* fs_file_name) {
char* vs_str = NULL;
char* fs_str = NULL;
GLuint vs, fs, sp;
long vs_sz, fs_sz;
int params = -1;
// work out size of files
vs_sz = get_file_size (vs_file_name);
fs_sz = get_file_size (fs_file_name);
if (!vs_sz || !fs_sz) {
return 0;
}
vs_str = (char*)malloc (vs_sz + 1); // oddly had to do +1 sometimes
fs_str = (char*)malloc (fs_sz + 1); // oddly had to do +1 sometimes
// read files intro strings
if (!parse_file_into_str (vs_file_name, vs_str)) {
return 0;
}
if (!parse_file_into_str (fs_file_name, fs_str)) {
return 0;
}
// create GPU shaders
vs = glCreateShader (GL_VERTEX_SHADER);
fs = glCreateShader (GL_FRAGMENT_SHADER);
glShaderSource (vs, 1, (const char**)&vs_str, NULL);
glShaderSource (fs, 1, (const char**)&fs_str, NULL);
free (vs_str);
free (fs_str);
glCompileShader (vs);
// check for compile errors
glGetShaderiv (vs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: vertex shader %s did not compile\n", vs_file_name);
print_shader_info_log (vs);
return 0; // or exit or something
}
glCompileShader (fs);
// check for compile errors
glGetShaderiv (fs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: frag shader %s did not compile\n", fs_file_name);
print_shader_info_log (fs);
return 0; // or exit or something
}
sp = glCreateProgram ();
glAttachShader (sp, vs);
glAttachShader (sp, fs);
glLinkProgram (sp);
return sp;
}
int init_shaders(Shader *shader,
const char *vertex_shader_loc,
const char *fragment_shader_loc)
{
int params = -1;
int length;
char vertex_shader_source[1024 * 256];
char fragment_shader_source[1024 * 256];
const GLchar *p;
parse_file_into_str(vertex_shader_loc, vertex_shader_source, 1024 * 256);
shader->vertexShader = glCreateShader(GL_VERTEX_SHADER);
p = (const GLchar *)vertex_shader_source;
glShaderSource(shader->vertexShader, 1, &p, NULL);
glCompileShader(shader->vertexShader);
glGetShaderiv(shader->vertexShader, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf(stderr, "ERROR: GL shader index %i did not compile\n", shader->vertexShader);
print_shader_info_log(shader->vertexShader);
return 1;
}
parse_file_into_str(fragment_shader_loc, fragment_shader_source, 1024 * 256);
shader->fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
p = (const GLchar *)fragment_shader_source;
glShaderSource(shader->fragmentShader, 1, &p, NULL);
glCompileShader(shader->fragmentShader);
glGetShaderiv(shader->fragmentShader, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf(stderr, "ERROR: GL shader index %i did not compile\n", shader->fragmentShader);
print_shader_info_log(shader->fragmentShader);
return 1;
}
shader->program = glCreateProgram();
glAttachShader(shader->program, shader->fragmentShader);
glAttachShader(shader->program, shader->vertexShader);
glLinkProgram(shader->program);
glGetProgramiv(shader->program, GL_LINK_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf(stderr, "ERROR: could not link shader programme GL index %i\n",shader->program);
print_program_info_log(shader->program);
return 1;
}
shader->projection_matrix_location = glGetUniformLocation(shader->program, "projection");
shader->view_matrix_location = glGetUniformLocation(shader->program, "view");
return 0;
}
bool create_shader (const char* file_name, GLuint* shader, GLenum type) {
gl_log ("creating shader from %s...\n", file_name);
char shader_string[MAX_SHADER_LENGTH];
assert (parse_file_into_str (file_name, shader_string, MAX_SHADER_LENGTH));
*shader = glCreateShader (type);
const GLchar* p = (const GLchar*)shader_string;
glShaderSource (*shader, 1, &p, NULL);
glCompileShader (*shader);
// check for compile errors
int params = -1;
glGetShaderiv (*shader, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
gl_log_err ("ERROR: GL shader index %i did not compile\n", *shader);
print_shader_info_log (*shader);
return false; // or exit or something
}
gl_log ("shader compiled. index %i\n", *shader);
return true;
}
int main () {
GLFWwindow* window = NULL;
const GLubyte* renderer;
const GLubyte* version;
GLuint shader_programme;
GLuint vao;
//
// Start OpenGL using helper libraries
// --------------------------------------------------------------------------
if (!glfwInit ()) {
fprintf (stderr, "ERROR: could not start GLFW3\n");
return 1;
}
/* change to 3.2 if on Apple OS X
glfwWindowHint (GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint (GLFW_CONTEXT_VERSION_MINOR, 0);
glfwWindowHint (GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
glfwWindowHint (GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); */
window = glfwCreateWindow (gl_width, gl_height, "Spinning Cube", NULL, NULL);
if (!window) {
fprintf (stderr, "ERROR: opening OS window\n");
return 1;
}
glfwMakeContextCurrent (window);
glewExperimental = GL_TRUE;
glewInit ();
/* get version info */
renderer = glGetString (GL_RENDERER); /* get renderer string */
version = glGetString (GL_VERSION); /* version as a string */
printf ("Renderer: %s\n", renderer);
printf ("OpenGL version supported %s\n", version);
int point_count = 0;
//
// Set up vertex buffers and vertex array object
// --------------------------------------------------------------------------
{
GLfloat* vp = NULL; // array of vertex points
GLfloat* vn = NULL; // array of vertex normals (we haven't used these yet)
GLfloat* vt = NULL; // array of texture coordinates (or these)
assert (load_obj_file ("cube.obj", vp, vt, vn, point_count));
GLuint points_vbo, texcoord_vbo;
glGenBuffers (1, &points_vbo);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
// copy our points from the header file into our VBO on graphics hardware
glBufferData (GL_ARRAY_BUFFER, sizeof (float) * 3 * point_count,
vp, GL_STATIC_DRAW);
// and grab the normals
glGenBuffers (1, &texcoord_vbo);
glBindBuffer (GL_ARRAY_BUFFER, texcoord_vbo);
glBufferData (GL_ARRAY_BUFFER, sizeof (float) * 2 * point_count,
vt, GL_STATIC_DRAW);
glGenVertexArrays (1, &vao);
glBindVertexArray (vao);
glEnableVertexAttribArray (0);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glVertexAttribPointer (0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (1);
glBindBuffer (GL_ARRAY_BUFFER, texcoord_vbo);
glVertexAttribPointer (1, 2, GL_FLOAT, GL_FALSE, 0, NULL);
free (vp);
free (vn);
free (vt);
}
//
// Load shaders from files
// --------------------------------------------------------------------------
{
char* vertex_shader_str;
char* fragment_shader_str;
// allocate some memory to store shader strings
vertex_shader_str = (char*)malloc (81920);
fragment_shader_str = (char*)malloc (81920);
// load shader strings from text files
assert (parse_file_into_str ("teapot.vert", vertex_shader_str, 81920));
assert (parse_file_into_str ("teapot.frag", fragment_shader_str, 81920));
GLuint vs, fs;
vs = glCreateShader (GL_VERTEX_SHADER);
fs = glCreateShader (GL_FRAGMENT_SHADER);
glShaderSource (vs, 1, (const char**)&vertex_shader_str, NULL);
glShaderSource (fs, 1, (const char**)&fragment_shader_str, NULL);
// free memory
free (vertex_shader_str);
free (fragment_shader_str);
glCompileShader (vs);
glCompileShader (fs);
shader_programme = glCreateProgram ();
glAttachShader (shader_programme, fs);
glAttachShader (shader_programme, vs);
glLinkProgram (shader_programme);
/* TODO NOTE: you should check for errors and print logs after compiling and also linking shaders */
}
//
// Create some matrices
// --------------------------------------------------------------------------
mat4 M, V, P;
M = identity_mat4 ();//scale (identity_mat4 (), vec3 (0.05, 0.05, 0.05));
vec3 cam_pos (0.0, 0.0, 5.0);
vec3 targ_pos (0.0, 0.0, 0.0);
vec3 up (0.0, 1.0, 0.0);
V = look_at (cam_pos, targ_pos, up);
P = perspective (67.0f, (float)gl_width / (float)gl_height, 0.1, 1000.0);
int M_loc = glGetUniformLocation (shader_programme, "M");
int V_loc = glGetUniformLocation (shader_programme, "V");
int P_loc = glGetUniformLocation (shader_programme, "P");
// send matrix values to shader immediately
glUseProgram (shader_programme);
glUniformMatrix4fv (M_loc, 1, GL_FALSE, M.m);
glUniformMatrix4fv (V_loc, 1, GL_FALSE, V.m);
glUniformMatrix4fv (P_loc, 1, GL_FALSE, P.m);
int dt_pixel_c = 16 * 16;
char* dt_data = (char*)malloc (4 * dt_pixel_c);
if (!dt_data) {
fprintf (stderr, "ERROR: out of memory. malloc default texture\n");
return 1;
}
for (int i = 0; i < dt_pixel_c * 4; i += 4) {
int sq_ac = i / 16;
if ((sq_ac / 2) * 2 == sq_ac) {
dt_data[i] = 0;
dt_data[i + 1] = 0;
dt_data[i + 2] = 0;
dt_data[i + 3] = (char)255;
} else {
dt_data[i] = (char)255;
dt_data[i + 1] = 0;
dt_data[i + 2] = (char)255;
dt_data[i + 3] = (char)255;
}
int sq_dn = i / (16 * 16);
if ((sq_dn / 2) * 2 == sq_dn) {
dt_data[i] = (char)255 - dt_data[i];
dt_data[i + 2] = (char)255 - dt_data[i + 2];
}
}
GLuint tex;
glGenTextures (1, &tex);
glActiveTexture (GL_TEXTURE0);
glBindTexture (GL_TEXTURE_2D, tex);
int x,y,n;
unsigned char *data = stbi_load ("move_me.png", &x, &y, &n, 4);
if (!data) {
fprintf (stderr, "ERROR: could not load image 'move_me.png'. using default texture\n");
glTexImage2D (
GL_TEXTURE_2D,
0,
GL_RGBA,
16,
16,
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
dt_data
);
} else {
glTexImage2D (
GL_TEXTURE_2D,
0,
GL_RGBA,
x,
y,
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
data
);
stbi_image_free(data);
data = NULL;
printf ("loaded image with [%i,%i] res and %i chans\n", x, y, n);
}
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_MAG_FILTER, GL_NEAREST);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
free (dt_data);
dt_data = NULL;
// */
//
// Start rendering
// --------------------------------------------------------------------------
// tell GL to only draw onto a pixel if the fragment is closer to the viewer
glEnable (GL_DEPTH_TEST); // enable depth-testing
glDepthFunc (GL_LESS); // depth-testing interprets a smaller value as "closer"
glClearColor (0.01, 0.01, 0.25, 1.0);
float a = 0.0f;
double prev = glfwGetTime ();
while (!glfwWindowShouldClose (window)) {
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// just the default viewport, covering the whole render area
glViewport (0, 0, gl_width, gl_height);
double curr = glfwGetTime ();
double elapsed = curr - prev;
prev = curr;
glUseProgram (shader_programme);
glBindVertexArray (vao);
a += sinf (elapsed * 50.0f);
M = rotate_y_deg (identity_mat4 (), a);
glUniformMatrix4fv (M_loc, 1, GL_FALSE, M.m);
glDrawArrays (GL_TRIANGLES, 0, point_count);
/* this just updates window events and keyboard input events (not used yet) */
glfwPollEvents ();
glfwSwapBuffers (window);
}
return 0;
}
int main () {
assert (restart_gl_log ());
// all the start-up code for GLFW and GLEW is called here
assert (start_gl ());
// tell GL to only draw onto a pixel if the shape is closer to the viewer
glEnable (GL_DEPTH_TEST); // enable depth-testing
glDepthFunc (GL_LESS); // depth-testing interprets a smaller value as "closer"
/* OTHER STUFF GOES HERE NEXT */
GLfloat points[] = {
0.0f, 0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
-0.5f, -0.5f, 0.0f
};
GLfloat colours[] = {
1.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 1.0f
};
glm::mat4 mvp = glm::mat4(1.0f);
GLuint points_vbo;
glGenBuffers (1, &points_vbo);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
// glBufferData (GL_ARRAY_BUFFER, 9 * sizeof (GLfloat), points, GL_STATIC_DRAW);
glBufferData (GL_ARRAY_BUFFER,
sizeof(g_vertex_buffer_data) * sizeof (GLfloat),
g_vertex_buffer_data,
GL_STATIC_DRAW);
/* create a second VBO, containing the array of colours.
note that we could also put them both into a single vertex buffer. in this
case we would use the pointer and stride parameters of glVertexAttribPointer()
to describe the different data layouts */
GLuint colours_vbo;
glGenBuffers (1, &colours_vbo);
glBindBuffer (GL_ARRAY_BUFFER, colours_vbo);
// glBufferData (GL_ARRAY_BUFFER, 9 * sizeof (GLfloat), colours, GL_STATIC_DRAW);
glBufferData (GL_ARRAY_BUFFER,
sizeof(g_color_buffer_data) * sizeof (GLfloat),
g_color_buffer_data,
GL_STATIC_DRAW);
/* create the VAO.
we bind each VBO in turn, and call glVertexAttribPointer() to indicate where
the memory should be fetched for vertex shader input variables 0, and 1,
respectively. we also have to explicitly enable both 'attribute' variables.
'attribute' is the older name for vertex shader 'in' variables. */
GLuint vao;
glGenVertexArrays (1, &vao);
glBindVertexArray (vao);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glVertexAttribPointer (0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glBindBuffer (GL_ARRAY_BUFFER, colours_vbo);
glVertexAttribPointer (1, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (0);
glEnableVertexAttribArray (1);
char vertex_shader[1024 * 256];
char fragment_shader[1024 * 256];
assert (parse_file_into_str ("test_vs.glsl", vertex_shader, 1024 * 256));
assert (parse_file_into_str ("test_fs.glsl", fragment_shader, 1024 * 256));
GLuint vs = glCreateShader (GL_VERTEX_SHADER);
const GLchar* p = (const GLchar*)vertex_shader;
glShaderSource (vs, 1, &p, NULL);
glCompileShader (vs);
// check for compile errors
int params = -1;
glGetShaderiv (vs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", vs);
print_shader_info_log (vs);
return 1; // or exit or something
}
GLuint fs = glCreateShader (GL_FRAGMENT_SHADER);
p = (const GLchar*)fragment_shader;
glShaderSource (fs, 1, &p, NULL);
glCompileShader (fs);
// check for compile errors
glGetShaderiv (fs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", fs);
print_shader_info_log (fs);
return 1; // or exit or something
}
GLuint shader_programme = glCreateProgram ();
glAttachShader (shader_programme, fs);
glAttachShader (shader_programme, vs);
glBindAttribLocation(shader_programme, 0, "vertex_position");
glBindAttribLocation(shader_programme, 1, "vertex_colour");
glLinkProgram (shader_programme);
glGetProgramiv (shader_programme, GL_LINK_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (
stderr,
"ERROR: could not link shader programme GL index %i\n",
shader_programme
);
print_programme_info_log (shader_programme);
return false;
}
//pass uniform
GLint u = glGetUniformLocation(shader_programme, "mvp");
assert (u > -1);
glUniformMatrix4fv(u, 1, GL_FALSE, &mvp[0][0]);
glEnable (GL_CULL_FACE); // cull face
glCullFace (GL_BACK); // cull back face
glFrontFace (GL_CW); // GL_CCW for counter clock-wise
while (!glfwWindowShouldClose (g_window)) {
_update_fps_counter (g_window);
// wipe the drawing surface clear
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glViewport (0, 0, g_gl_width, g_gl_height);
glUseProgram (shader_programme);
glBindVertexArray (vao);
// draw points 0-3 from the currently bound VAO with current in-use shader
glDrawArrays (GL_TRIANGLES, 0, 12* 3);
// update other events like input handling
glfwPollEvents ();
if (GLFW_PRESS == glfwGetKey (g_window, GLFW_KEY_ESCAPE)) {
glfwSetWindowShouldClose (g_window, 1);
}
// put the stuff we've been drawing onto the display
glfwSwapBuffers (g_window);
}
// close GL context and any other GLFW resources
glfwTerminate();
return 0;
}
int main () {
GLFWwindow* window = NULL;
const GLubyte* renderer;
const GLubyte* version;
GLuint cube_sp, knot_sp;
GLuint vao;
//
// Start OpenGL using helper libraries
// --------------------------------------------------------------------------
if (!glfwInit ()) {
fprintf (stderr, "ERROR: could not start GLFW3\n");
return 1;
}
/* change to 3.2 if on Apple OS X
glfwWindowHint (GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint (GLFW_CONTEXT_VERSION_MINOR, 0);
glfwWindowHint (GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
glfwWindowHint (GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); */
glfwWindowHint (GLFW_SAMPLES, msaa);
window = glfwCreateWindow (gl_width, gl_height, "{quadratic bezier}", NULL, NULL);
if (!window) {
fprintf (stderr, "ERROR: opening OS window\n");
return 1;
}
glfwMakeContextCurrent (window);
glewExperimental = GL_TRUE;
glewInit ();
/* get version info */
renderer = glGetString (GL_RENDERER); /* get renderer string */
version = glGetString (GL_VERSION); /* version as a string */
printf ("Renderer: %s\n", renderer);
printf ("OpenGL version supported %s\n", version);
int point_count = 0;
//
// Set up vertex buffers and vertex array object
// --------------------------------------------------------------------------
{
GLfloat* vp = NULL; // array of vertex points
GLfloat* vn = NULL; // array of vertex normals (we haven't used these yet)
GLfloat* vt = NULL; // array of texture coordinates (or these)
assert (load_obj_file ("smcube.obj", vp, vt, vn, point_count));
GLuint points_vbo, texcoord_vbo, normal_vbo;
glGenBuffers (1, &points_vbo);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glBufferData (GL_ARRAY_BUFFER, sizeof (float) * 3 * point_count,
vp, GL_STATIC_DRAW);
glGenBuffers (1, &texcoord_vbo);
glBindBuffer (GL_ARRAY_BUFFER, texcoord_vbo);
glBufferData (GL_ARRAY_BUFFER, sizeof (float) * 2 * point_count,
vt, GL_STATIC_DRAW);
glGenBuffers (1, &normal_vbo);
glBindBuffer (GL_ARRAY_BUFFER, normal_vbo);
glBufferData (GL_ARRAY_BUFFER, sizeof (float) * 3 * point_count,
vn, GL_STATIC_DRAW);
glGenVertexArrays (1, &vao);
glBindVertexArray (vao);
glEnableVertexAttribArray (0);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glVertexAttribPointer (0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (1);
glBindBuffer (GL_ARRAY_BUFFER, texcoord_vbo);
glVertexAttribPointer (1, 2, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (2);
glBindBuffer (GL_ARRAY_BUFFER, normal_vbo);
glVertexAttribPointer (2, 3, GL_FLOAT, GL_FALSE, 0, NULL);
free (vp);
free (vn);
free (vt);
}
//
// Load shaders from files
// --------------------------------------------------------------------------
{
char* vertex_shader_str;
char* fragment_shader_str;
// allocate some memory to store shader strings
vertex_shader_str = (char*)malloc (81920);
fragment_shader_str = (char*)malloc (81920);
// load shader strings from text files
assert (parse_file_into_str ("cube.vert", vertex_shader_str, 81920));
assert (parse_file_into_str ("cube.frag", fragment_shader_str, 81920));
GLuint vs, fs;
vs = glCreateShader (GL_VERTEX_SHADER);
fs = glCreateShader (GL_FRAGMENT_SHADER);
glShaderSource (vs, 1, (const char**)&vertex_shader_str, NULL);
glShaderSource (fs, 1, (const char**)&fragment_shader_str, NULL);
// free memory
free (vertex_shader_str);
free (fragment_shader_str);
glCompileShader (vs);
glCompileShader (fs);
cube_sp = glCreateProgram ();
glAttachShader (cube_sp, fs);
glAttachShader (cube_sp, vs);
glBindAttribLocation (cube_sp, 0, "vp");
glBindAttribLocation (cube_sp, 1, "vt");
glBindAttribLocation (cube_sp, 2, "vn");
glLinkProgram (cube_sp);
}
{
char* vertex_shader_str;
char* fragment_shader_str;
// allocate some memory to store shader strings
vertex_shader_str = (char*)malloc (81920);
fragment_shader_str = (char*)malloc (81920);
// load shader strings from text files
assert (parse_file_into_str ("knot.vert", vertex_shader_str, 81920));
assert (parse_file_into_str ("knot.frag", fragment_shader_str, 81920));
GLuint vs, fs;
vs = glCreateShader (GL_VERTEX_SHADER);
fs = glCreateShader (GL_FRAGMENT_SHADER);
glShaderSource (vs, 1, (const char**)&vertex_shader_str, NULL);
glShaderSource (fs, 1, (const char**)&fragment_shader_str, NULL);
// free memory
free (vertex_shader_str);
free (fragment_shader_str);
glCompileShader (vs);
glCompileShader (fs);
knot_sp = glCreateProgram ();
glAttachShader (knot_sp, fs);
glAttachShader (knot_sp, vs);
glLinkProgram (knot_sp);
}
//
// Create some matrices
// --------------------------------------------------------------------------
mat4 M, V, P;
M = identity_mat4 ();//scale (identity_mat4 (), vec3 (0.05, 0.05, 0.05));
vec3 cam_pos (0.0, 0.0, 15.0);
vec3 targ_pos (0.0, 0.0, 0.0);
vec3 up = normalise (vec3 (0.0, 1.0, 0.0));
V = look_at (cam_pos, targ_pos, up);
P = perspective (67.0f, (float)gl_width / (float)gl_height, 0.1, 1000.0);
int M_loc = glGetUniformLocation (cube_sp, "M");
int V_loc = glGetUniformLocation (cube_sp, "V");
int P_loc = glGetUniformLocation (cube_sp, "P");
int A_loc = glGetUniformLocation (cube_sp, "A");
int B_loc = glGetUniformLocation (cube_sp, "B");
int C_loc = glGetUniformLocation (cube_sp, "C");
int t_loc = glGetUniformLocation (cube_sp, "t");
// send matrix values to shader immediately
glUseProgram (cube_sp);
glUniformMatrix4fv (M_loc, 1, GL_FALSE, M.m);
glUniformMatrix4fv (V_loc, 1, GL_FALSE, V.m);
glUniformMatrix4fv (P_loc, 1, GL_FALSE, P.m);
//
// specific knots for bezier here A, C are start, end, B is control point
//
vec3 A = vec3 (-7.0f, -5.0f, 0.0f);
vec3 B = vec3 (0.0f, 8.0f, 0.0f);
vec3 C = vec3 (7.0f, -5.0f, 0.0f);
glUniform3fv (A_loc, 1, A.v);
glUniform3fv (B_loc, 1, B.v);
glUniform3fv (C_loc, 1, C.v);
int knot_loc = glGetUniformLocation (knot_sp, "pos");
int knotP_loc = glGetUniformLocation (knot_sp, "P");
int knotV_loc = glGetUniformLocation (knot_sp, "V");
glUseProgram (knot_sp);
glUniformMatrix4fv (knotV_loc, 1, GL_FALSE, V.m);
glUniformMatrix4fv (knotP_loc, 1, GL_FALSE, P.m);
//
// Start rendering
// --------------------------------------------------------------------------
// tell GL to only draw onto a pixel if the fragment is closer to the viewer
glEnable (GL_DEPTH_TEST); // enable depth-testing
glDepthFunc (GL_LESS); // depth-testing interprets a smaller value as "closer"
glDepthFunc (GL_LESS); // depth-testing is to use a "less than" function
glEnable (GL_CULL_FACE); // enable culling of faces
glCullFace (GL_BACK);
glFrontFace (GL_CCW);
glClearColor (0.04, 0.04, 0.75, 1.0);
/* Render Points, allow resize in vertex shader */
glEnable (GL_PROGRAM_POINT_SIZE);
glPointParameteri (GL_POINT_SPRITE_COORD_ORIGIN, GL_LOWER_LEFT);
float t = 0.0f;
float speed = 0.5f;
double prev = glfwGetTime ();
while (!glfwWindowShouldClose (window)) {
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// just the default viewport, covering the whole render area
glViewport (0, 0, gl_width, gl_height);
double curr = glfwGetTime ();
double elapsed = curr - prev;
prev = curr;
//
// move along spline
if (GLFW_PRESS == glfwGetKey (window, GLFW_KEY_LEFT)) {
t -= elapsed * speed;
if (t < 0.0f) {
t = 0.0f;
}
}
if (GLFW_PRESS == glfwGetKey (window, GLFW_KEY_RIGHT)) {
t += elapsed * speed;
if (t > 1.0f) {
t = 1.0f;
}
}
//
// render 3 knots
glEnable (GL_PROGRAM_POINT_SIZE);
glUseProgram (knot_sp);
glUniform3fv (knot_loc, 1, A.v);
glDrawArrays (GL_POINTS, 0, 1);
glUseProgram (knot_sp);
glUniform3fv (knot_loc, 1, B.v);
glDrawArrays (GL_POINTS, 0, 1);
glUseProgram (knot_sp);
glUniform3fv (knot_loc, 1, C.v);
glDrawArrays (GL_POINTS, 0, 1);
glDisable (GL_PROGRAM_POINT_SIZE);
glUseProgram (cube_sp);
glBindVertexArray (vao);
M = identity_mat4 ();//rotate_y_deg (identity_mat4 (), a);
glUniformMatrix4fv (M_loc, 1, GL_FALSE, M.m);
glUniform1f (t_loc, t);
glDrawArrays (GL_TRIANGLES, 0, point_count);
/* this just updates window events and keyboard input events (not used yet) */
glfwPollEvents ();
glfwSwapBuffers (window);
}
return 0;
}
int main () {
restart_gl_log ();
// all the GLFW and GLEW start-up code is moved to here in gl_utils.cpp
start_gl ();
// tell GL to only draw onto a pixel if the shape is closer to the viewer
glEnable (GL_DEPTH_TEST); // enable depth-testing
glDepthFunc (GL_LESS); // depth-testing interprets a smaller value as "closer"
/* OTHER STUFF GOES HERE NEXT */
GLfloat points[] = {
0.0f, 0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
-0.5f, -0.5f, 0.0f
};
GLfloat colours[] = {
1.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 1.0f
};
GLuint points_vbo;
glGenBuffers (1, &points_vbo);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glBufferData (GL_ARRAY_BUFFER, 9 * sizeof (GLfloat), points, GL_STATIC_DRAW);
GLuint colours_vbo;
glGenBuffers (1, &colours_vbo);
glBindBuffer (GL_ARRAY_BUFFER, colours_vbo);
glBufferData (GL_ARRAY_BUFFER, 9 * sizeof (GLfloat), colours, GL_STATIC_DRAW);
GLuint vao;
glGenVertexArrays (1, &vao);
glBindVertexArray (vao);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glVertexAttribPointer (0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glBindBuffer (GL_ARRAY_BUFFER, colours_vbo);
glVertexAttribPointer (1, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (0);
glEnableVertexAttribArray (1);
char vertex_shader[1024 * 256];
char fragment_shader[1024 * 256];
parse_file_into_str ("test_vs.glsl", vertex_shader, 1024 * 256);
parse_file_into_str ("test_fs.glsl", fragment_shader, 1024 * 256);
GLuint vs = glCreateShader (GL_VERTEX_SHADER);
const GLchar* p = (const GLchar*)vertex_shader;
glShaderSource (vs, 1, &p, NULL);
glCompileShader (vs);
// check for compile errors
int params = -1;
glGetShaderiv (vs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", vs);
print_shader_info_log (vs);
return 1; // or exit or something
}
GLuint fs = glCreateShader (GL_FRAGMENT_SHADER);
p = (const GLchar*)fragment_shader;
glShaderSource (fs, 1, &p, NULL);
glCompileShader (fs);
// check for compile errors
glGetShaderiv (fs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", fs);
print_shader_info_log (fs);
return 1; // or exit or something
}
GLuint shader_programme = glCreateProgram ();
glAttachShader (shader_programme, fs);
glAttachShader (shader_programme, vs);
glLinkProgram (shader_programme);
glGetProgramiv (shader_programme, GL_LINK_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (
stderr,
"ERROR: could not link shader programme GL index %i\n",
shader_programme
);
print_programme_info_log (shader_programme);
return false;
}
GLfloat matrix[] = {
1.0f, 0.0f, 0.0f, 0.0f, // first column
0.0f, 1.0f, 0.0f, 0.0f, // second column
0.0f, 0.0f, 1.0f, 0.0f, // third column
0.5f, 0.0f, 0.0f, 1.0f // fourth column
};
int matrix_location = glGetUniformLocation (shader_programme, "matrix");
glUseProgram (shader_programme);
glUniformMatrix4fv (matrix_location, 1, GL_FALSE, matrix);
glEnable (GL_CULL_FACE); // cull face
glCullFace (GL_BACK); // cull back face
glFrontFace (GL_CW); // GL_CCW for counter clock-wise
float speed = 1.0f; // move at 1 unit per second
float last_position = 0.0f;
while (!glfwWindowShouldClose (g_window)) {
// add a timer for doing animation
static double previous_seconds = glfwGetTime ();
double current_seconds = glfwGetTime ();
double elapsed_seconds = current_seconds - previous_seconds;
previous_seconds = current_seconds;
_update_fps_counter (g_window);
// wipe the drawing surface clear
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glViewport (0, 0, g_gl_width, g_gl_height);
//
// Note: this call is not necessary, but I like to do it anyway before any
// time that I call glDrawArrays() so I never use the wrong shader programme
glUseProgram (shader_programme);
// update the matrix
// - you could simplify this by just using sin(current_seconds)
matrix[12] = elapsed_seconds * speed + last_position;
last_position = matrix[12];
if (fabs (last_position) > 1.0) {
speed = -speed;
}
//
// Note: this call is related to the most recently 'used' shader programme
glUniformMatrix4fv (matrix_location, 1, GL_FALSE, matrix);
//
// Note: this call is not necessary, but I like to do it anyway before any
// time that I call glDrawArrays() so I never use the wrong vertex data
glBindVertexArray (vao);
// draw points 0-3 from the currently bound VAO with current in-use shader
glDrawArrays (GL_TRIANGLES, 0, 3);
// update other events like input handling
glfwPollEvents ();
if (GLFW_PRESS == glfwGetKey (g_window, GLFW_KEY_ESCAPE)) {
glfwSetWindowShouldClose (g_window, 1);
}
// put the stuff we've been drawing onto the display
glfwSwapBuffers (g_window);
}
// close GL context and any other GLFW resources
glfwTerminate();
return 0;
}
int main(){
assert(restart_gl_log());
assert(start_gl());
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
GLfloat points[] = {
0.0f, 0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
-0.5f, -0.5f, 0.0f
};
GLfloat colours[] = {
1.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 1.0f
};
GLuint vao;
char vertex_shader[1024 * 256];
char fragmet_shader[1024 * 256];
GLuint vs, fs, shader_programme;
const GLchar* p;
int params = -1;
GLuint points_vbo;
GLuint colours_vbo;
glGenBuffers(1, &points_vbo);
glBindBuffer(GL_ARRAY_BUFFER, points_vbo);
glBufferData(GL_ARRAY_BUFFER, 9 * sizeof(GLfloat), points, GL_STATIC_DRAW);
/* create a second VBO, containing the array of colours.
note that we could also put them both into a single vertex buffer. in this
case we would use the pointer and stride parameters of glVertexAttribPointer()
to describe the different data layouts */
glGenBuffers(1, &colours_vbo);
glBindBuffer(GL_ARRAY_BUFFER, colours_vbo);
glBufferData(GL_ARRAY_BUFFER, 9 * sizeof(GLfloat), colours, GL_STATIC_DRAW);
/* create the VAO.
we bind each VBO in turn, and call glVertexAttribPointer() to indicate where
the memory should be fetched for vertex shader input variables 0, and 1,
respectively. we also have to explicitly enable both 'attribute' variables.
'attribute' is the older name for vertex shader 'in' variables. */
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
glBindBuffer(GL_ARRAY_BUFFER, points_vbo);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glBindBuffer(GL_ARRAY_BUFFER, colours_vbo);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
// Load shaders from files here
assert(parse_file_into_str("test_vs.glsl", vertex_shader, 1024*256));
assert(parse_file_into_str("test_fs.glsl", fragmet_shader, 1024*256));
vs = glCreateShader(GL_VERTEX_SHADER);
p = (const GLchar*)vertex_shader;
glShaderSource(vs, 1, &p, NULL);
glCompileShader(vs);
// Check for shader compile errors
glGetShaderiv(vs, GL_COMPILE_STATUS, ¶ms);
if(GL_TRUE != params){
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", vs);
_print_shader_info_log (vs);
return 1; /* or exit or something */
}
fs = glCreateShader(GL_FRAGMENT_SHADER);
p = (const GLchar*)fragmet_shader;
glShaderSource (fs, 1, &p, NULL);
glCompileShader (fs);
// Check for shader compile errors
glGetShaderiv(fs, GL_COMPILE_STATUS, ¶ms);
if(GL_TRUE != params){
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", fs);
_print_shader_info_log (fs);
return 1; /* or exit or something */
}
shader_programme = glCreateProgram();
glAttachShader(shader_programme, fs);
glAttachShader(shader_programme, vs);
glLinkProgram(shader_programme);
/* check for shader linking errors - very important! */
glGetProgramiv (shader_programme, GL_LINK_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (
stderr,
"ERROR: could not link shader programme GL index %i\n",
shader_programme
);
_print_programme_info_log (shader_programme);
return 1;
}
glEnable (GL_CULL_FACE); // cull face
glCullFace (GL_BACK); // cull back face
glFrontFace (GL_CW); // GL_CCW for counter clock-wise
while(!glfwWindowShouldClose(g_window)){
_update_fps_counter(g_window);
// wipe the drawing surface clear
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glViewport(0, 0, g_gl_width, g_gl_height);
glUseProgram(shader_programme);
glBindVertexArray(vao);
/* draw points 0-3 from the currently bound VAO with current in-use
shader */
glDrawArrays(GL_TRIANGLES, 0, 3);
// Update events like input
glfwPollEvents();
if(GLFW_PRESS == glfwGetKey(g_window, GLFW_KEY_ESCAPE)){
glfwSetWindowShouldClose(g_window, 1);
}
// put the stuff we ve been drawing onto the display
glfwSwapBuffers(g_window);
}
// close GL context and any other GLFW resources
glfwTerminate();
return 0;
}
int main () {
GLfloat points[] = {
0.0f, 0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
-0.5f, -0.5f, 0.0f
};
GLuint vbo;
GLuint vao;
char vertex_shader[1024 * 256];
char fragment_shader[1024 * 256];
GLuint vs, fs, shader_programme;
const GLchar* p;
int params = -1;
GLint colour_loc;
assert (restart_gl_log ());
assert (start_gl ());
/* tell GL to only draw onto a pixel if the shape is closer to the viewer */
glEnable (GL_DEPTH_TEST); /* enable depth-testing */
glDepthFunc (GL_LESS); /* depth-testing interprets a smaller value as "closer" */
glGenBuffers (1, &vbo);
glBindBuffer (GL_ARRAY_BUFFER, vbo);
glBufferData (GL_ARRAY_BUFFER, 9 * sizeof (GLfloat), points, GL_STATIC_DRAW);
glGenVertexArrays (1, &vao);
glBindVertexArray (vao);
glEnableVertexAttribArray (0);
glBindBuffer (GL_ARRAY_BUFFER, vbo);
glVertexAttribPointer (0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
/* load shaders from files here */
assert (parse_file_into_str ("test_vs.glsl", vertex_shader, 1024 * 256));
assert (parse_file_into_str ("test_fs.glsl", fragment_shader, 1024 * 256));
vs = glCreateShader (GL_VERTEX_SHADER);
p = (const GLchar*)vertex_shader;
glShaderSource (vs, 1, &p, NULL);
glCompileShader (vs);
/* check for shader compile errors - very important! */
glGetShaderiv (vs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", vs);
_print_shader_info_log (vs);
return 1; /* or exit or something */
}
fs = glCreateShader (GL_FRAGMENT_SHADER);
p = (const GLchar*)fragment_shader;
glShaderSource (fs, 1, &p, NULL);
glCompileShader (fs);
/* check for compile errors */
glGetShaderiv (fs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", fs);
_print_shader_info_log (fs);
return 1; /* or exit or something */
}
shader_programme = glCreateProgram ();
glAttachShader (shader_programme, fs);
glAttachShader (shader_programme, vs);
glLinkProgram (shader_programme);
/* check for shader linking errors - very important! */
glGetProgramiv (shader_programme, GL_LINK_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (
stderr,
"ERROR: could not link shader programme GL index %i\n",
shader_programme
);
_print_programme_info_log (shader_programme);
return 1;
}
print_all (shader_programme);
assert (is_valid (shader_programme));
colour_loc = glGetUniformLocation (shader_programme, "inputColour");
assert (colour_loc > -1);
glUseProgram (shader_programme);
glUniform4f (colour_loc, 1.0f, 0.0f, 0.0f, 1.0f);
while (!glfwWindowShouldClose (g_window)) {
_update_fps_counter (g_window);
/* wipe the drawing surface clear */
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glViewport (0, 0, g_gl_width, g_gl_height);
glUseProgram (shader_programme);
glBindVertexArray (vao);
/* draw points 0-3 from the currently bound VAO with current in-use shader */
glDrawArrays (GL_TRIANGLES, 0, 3);
/* update other events like input handling */
glfwPollEvents ();
if (GLFW_PRESS == glfwGetKey (g_window, GLFW_KEY_ESCAPE)) {
glfwSetWindowShouldClose (g_window, 1);
}
/* put the stuff we've been drawing onto the display */
glfwSwapBuffers (g_window);
}
/* close GL context and any other GLFW resources */
glfwTerminate();
return 0;
}
int main () {
GLFWwindow* window = NULL;
const GLubyte* renderer;
const GLubyte* version;
GLuint shader_programme;
GLuint vao;
//
// Start OpenGL using helper libraries
// --------------------------------------------------------------------------
if (!glfwInit ()) {
fprintf (stderr, "ERROR: could not start GLFW3\n");
return 1;
}
// change to 3.2 if on Apple OS X
glfwWindowHint (GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint (GLFW_CONTEXT_VERSION_MINOR, 2);
glfwWindowHint (GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
glfwWindowHint (GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwWindowHint (GLFW_SAMPLES, msaa);
window = glfwCreateWindow (gl_width, gl_height, "Textured Mesh", NULL, NULL);
if (!window) {
fprintf (stderr, "ERROR: opening OS window\n");
return 1;
}
glfwMakeContextCurrent (window);
glewExperimental = GL_TRUE;
glewInit ();
/* get version info */
renderer = glGetString (GL_RENDERER); /* get renderer string */
version = glGetString (GL_VERSION); /* version as a string */
printf ("Renderer: %s\n", renderer);
printf ("OpenGL version supported %s\n", version);
int point_count = 0;
//
// Set up vertex buffers and vertex array object
// --------------------------------------------------------------------------
{
GLfloat* vp = NULL; // array of vertex points
GLfloat* vn = NULL; // array of vertex normals (we haven't used these yet)
GLfloat* vt = NULL; // array of texture coordinates (or these)
//assert (load_obj_file ("cube.obj", vp, vt, vn, point_count));
assert (load_obj_file ("monkey.obj", vp, vt, vn, point_count));
GLuint points_vbo, texcoord_vbo, normal_vbo;
glGenBuffers (1, &points_vbo);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glBufferData (GL_ARRAY_BUFFER, sizeof (float) * 3 * point_count,
vp, GL_STATIC_DRAW);
glGenBuffers (1, &texcoord_vbo);
glBindBuffer (GL_ARRAY_BUFFER, texcoord_vbo);
glBufferData (GL_ARRAY_BUFFER, sizeof (float) * 2 * point_count,
vt, GL_STATIC_DRAW);
glGenBuffers (1, &normal_vbo);
glBindBuffer (GL_ARRAY_BUFFER, normal_vbo);
glBufferData (GL_ARRAY_BUFFER, sizeof (float) * 3 * point_count,
vn, GL_STATIC_DRAW);
glGenVertexArrays (1, &vao);
glBindVertexArray (vao);
glEnableVertexAttribArray (0);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glVertexAttribPointer (0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (1);
glBindBuffer (GL_ARRAY_BUFFER, texcoord_vbo);
glVertexAttribPointer (1, 2, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (2);
glBindBuffer (GL_ARRAY_BUFFER, normal_vbo);
glVertexAttribPointer (2, 3, GL_FLOAT, GL_FALSE, 0, NULL);
free (vp);
free (vn);
free (vt);
}
//
// Load shaders from files
// --------------------------------------------------------------------------
{
char* vertex_shader_str;
char* fragment_shader_str;
// allocate some memory to store shader strings
vertex_shader_str = (char*)malloc (81920);
fragment_shader_str = (char*)malloc (81920);
// load shader strings from text files
assert (parse_file_into_str ("teapot.vert", vertex_shader_str, 81920));
assert (parse_file_into_str ("teapot.frag", fragment_shader_str, 81920));
GLuint vs, fs;
vs = glCreateShader (GL_VERTEX_SHADER);
fs = glCreateShader (GL_FRAGMENT_SHADER);
glShaderSource (vs, 1, (const char**)&vertex_shader_str, NULL);
glShaderSource (fs, 1, (const char**)&fragment_shader_str, NULL);
// free memory
free (vertex_shader_str);
free (fragment_shader_str);
int params = -1;
glCompileShader (vs);
glGetShaderiv (vs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
printf ("ERROR: GL shader index %i (teapot.vert) did not compile\n", vs);
int max_length = 2048;
int actual_length = 0;
char log[2048];
glGetShaderInfoLog (vs, max_length, &actual_length, log);
printf ("shader info log for GL index %u\n%s\n", vs, log);
}
glCompileShader (fs);
glGetShaderiv (fs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
printf ("ERROR: GL shader index %i (teapot.frag) did not compile\n", fs);
int max_length = 2048;
int actual_length = 0;
char log[2048];
glGetShaderInfoLog (fs, max_length, &actual_length, log);
printf ("shader info log for GL index %u\n%s\n", vs, log);
}
shader_programme = glCreateProgram ();
glAttachShader (shader_programme, fs);
glAttachShader (shader_programme, vs);
glBindAttribLocation (shader_programme, 0, "vp");
glBindAttribLocation (shader_programme, 1, "vt");
glBindAttribLocation (shader_programme, 2, "vn");
glLinkProgram (shader_programme);
glGetProgramiv (shader_programme, GL_LINK_STATUS, ¶ms);
if (GL_TRUE != params) {
printf ("ERROR: could not link shader programme GL index %u\n", shader_programme);
int max_length = 2048;
int actual_length = 0;
char log[2048];
glGetProgramInfoLog (shader_programme, max_length, &actual_length, log);
printf ("program info log for GL index %u\n%s\n", shader_programme, log);
}
/* TODO NOTE: you should check for errors and print logs after compiling and also linking shaders */
}
//
// Create some matrices
// --------------------------------------------------------------------------
mat4 M, V, P;
M = identity_mat4 ();//scale (identity_mat4 (), vec3 (0.05, 0.05, 0.05));
vec3 cam_pos (0.0, 5.0, 5.0);
vec3 targ_pos (0.0, 0.0, 0.0);
vec3 up = normalise (vec3 (0.0, 1.0, -1.0));
V = look_at (cam_pos, targ_pos, up);
P = perspective (67.0f, (float)gl_width / (float)gl_height, 0.1, 10.0);
int M_loc = glGetUniformLocation (shader_programme, "M");
int V_loc = glGetUniformLocation (shader_programme, "V");
int P_loc = glGetUniformLocation (shader_programme, "P");
int ol_loc = glGetUniformLocation (shader_programme, "ol_mode");
int sm_loc = glGetUniformLocation (shader_programme, "sm_shaded");
// send matrix values to shader immediately
glUseProgram (shader_programme);
glUniformMatrix4fv (M_loc, 1, GL_FALSE, M.m);
glUniformMatrix4fv (V_loc, 1, GL_FALSE, V.m);
glUniformMatrix4fv (P_loc, 1, GL_FALSE, P.m);
glUniform1f (ol_loc, 0.0f);
glUniform1f (sm_loc, 0.0f);
//
// Start rendering
// --------------------------------------------------------------------------
// tell GL to only draw onto a pixel if the fragment is closer to the viewer
glEnable (GL_DEPTH_TEST); // enable depth-testing
glDepthFunc (GL_LESS); // depth-testing interprets a smaller value as "closer"
glDepthFunc (GL_LESS); // depth-testing is to use a "less than" function
glEnable (GL_CULL_FACE); // enable culling of faces
glCullFace (GL_BACK);
glFrontFace (GL_CCW);
glClearColor (0.04, 0.04, 0.75, 1.0);
bool multi_pass = true;
GLuint fb, c_tex, d_tex;;
{
// fb
glGenFramebuffers (1, &fb);
glBindFramebuffer (GL_FRAMEBUFFER, fb);
glGenTextures (1, &c_tex);
glGenTextures (1, &d_tex);
glActiveTexture (GL_TEXTURE0);
glBindTexture (GL_TEXTURE_2D, c_tex);
glTexImage2D (GL_TEXTURE_2D, 0, GL_RGBA, gl_width, gl_height, 0, GL_RGBA,
GL_UNSIGNED_BYTE, NULL);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
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_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
c_tex, 0);
glBindTexture (GL_TEXTURE_2D, d_tex);
glTexImage2D (GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, gl_width, gl_height, 0,
GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
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_ATTACHMENT, GL_TEXTURE_2D,
d_tex, 0);
glBindFramebuffer (GL_FRAMEBUFFER, 0);
}
GLuint quad_vao;
{
float quad_pts[] = {-1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0};
GLuint quad_vbo;
glGenBuffers (1, &quad_vbo);
glGenVertexArrays (1, &quad_vao);
glBindVertexArray (quad_vao);
glEnableVertexAttribArray (0);
glBindBuffer (GL_ARRAY_BUFFER, quad_vbo);
glBufferData (GL_ARRAY_BUFFER, 8 * sizeof (float), quad_pts, GL_STATIC_DRAW);
glVertexAttribPointer (0, 2, GL_FLOAT, GL_FALSE, 0, NULL);
}
GLuint post_sp;
{
char* vertex_shader_str;
char* fragment_shader_str;
// allocate some memory to store shader strings
vertex_shader_str = (char*)malloc (81920);
fragment_shader_str = (char*)malloc (81920);
// load shader strings from text files
assert (parse_file_into_str ("post.vert", vertex_shader_str, 81920));
assert (parse_file_into_str ("post.frag", fragment_shader_str, 81920));
GLuint vs, fs;
vs = glCreateShader (GL_VERTEX_SHADER);
fs = glCreateShader (GL_FRAGMENT_SHADER);
glShaderSource (vs, 1, (const char**)&vertex_shader_str, NULL);
glShaderSource (fs, 1, (const char**)&fragment_shader_str, NULL);
// free memory
free (vertex_shader_str);
free (fragment_shader_str);
int params = -1;
glCompileShader (vs);
glGetShaderiv (vs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
printf ("ERROR: GL shader index %i (post.vert) did not compile\n", vs);
int max_length = 2048;
int actual_length = 0;
char log[2048];
glGetShaderInfoLog (vs, max_length, &actual_length, log);
printf ("shader info log for GL index %u\n%s\n", vs, log);
}
glCompileShader (fs);
glGetShaderiv (fs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
printf ("ERROR: GL shader index %i (post.frag) did not compile\n", fs);
int max_length = 2048;
int actual_length = 0;
char log[2048];
glGetShaderInfoLog (fs, max_length, &actual_length, log);
printf ("shader info log for GL index %u\n%s\n", vs, log);
}
post_sp = glCreateProgram ();
glAttachShader (post_sp, fs);
glAttachShader (post_sp, vs);
glBindAttribLocation (post_sp, 0, "vp");
glLinkProgram (post_sp);
glGetProgramiv (post_sp, GL_LINK_STATUS, ¶ms);
if (GL_TRUE != params) {
printf ("ERROR: could not link shader programme GL index %u\n", post_sp);
int max_length = 2048;
int actual_length = 0;
char log[2048];
glGetProgramInfoLog (post_sp, max_length, &actual_length, log);
printf ("program info log for GL index %u\n%s\n", post_sp, log);
}
}
double a = 0.0f;
double prev = glfwGetTime ();
while (!glfwWindowShouldClose (window)) {
if (multi_pass) {
glBindFramebuffer (GL_FRAMEBUFFER, fb);
}
glViewport (0, 0, gl_width, gl_height);
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glActiveTexture (GL_TEXTURE0);
glBindTexture (GL_TEXTURE_2D, 0);
double curr = glfwGetTime ();
double elapsed = curr - prev;
prev = curr;
glUseProgram (shader_programme);
glBindVertexArray (vao);
a += elapsed * 50.0f;
//float ang = (float)sin (a);
M = rotate_y_deg (identity_mat4 (), a);
glUniformMatrix4fv (M_loc, 1, GL_FALSE, M.m);
glUniform1f (sm_loc, 1.0f); // smooth shaded or not (exception is flat-shaded, they might not be great
// if non-cube anyway due to scaling)
if (!multi_pass) {
glFrontFace (GL_CW);
glUniform1f (ol_loc, 1.0f);
glDrawArrays (GL_TRIANGLES, 0, point_count);
}
glFrontFace (GL_CCW);
glUniform1f (ol_loc, 0.0f);
glDrawArrays (GL_TRIANGLES, 0, point_count);
/* this just updates window events and keyboard input events (not used yet) */
if (multi_pass) {
glFlush ();
glFinish ();
glBindFramebuffer (GL_FRAMEBUFFER, 0);
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glViewport (0, 0, gl_width, gl_height);
glUseProgram (post_sp);
glActiveTexture (GL_TEXTURE0);
glBindTexture (GL_TEXTURE_2D, d_tex);
glBindVertexArray (quad_vao);
glDrawArrays (GL_TRIANGLE_STRIP, 0, 4);
}
glfwPollEvents ();
glfwSwapBuffers (window);
}
return 0;
}
int main () {
assert (restart_gl_log ());
assert (start_gl ());
// tell GL to only draw onto a pixel if the shape is closer to the viewer
glEnable (GL_DEPTH_TEST); // enable depth-testing
glDepthFunc (GL_LESS); // depth-testing interprets a smaller value as "closer"
glClearColor (0.2, 0.2, 0.2, 1.0);
GLfloat points[] = {
0.0f, 0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
-0.5f, -0.5f, 0.0f
};
GLfloat colours[] = {
1.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 1.0f
};
GLuint points_vbo;
glGenBuffers (1, &points_vbo);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glBufferData (GL_ARRAY_BUFFER, 9 * sizeof (GLfloat), points, GL_STATIC_DRAW);
GLuint colours_vbo;
glGenBuffers (1, &colours_vbo);
glBindBuffer (GL_ARRAY_BUFFER, colours_vbo);
glBufferData (GL_ARRAY_BUFFER, 9 * sizeof (GLfloat), colours, GL_STATIC_DRAW);
GLuint vao;
glGenVertexArrays (1, &vao);
glBindVertexArray (vao);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glVertexAttribPointer (0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glBindBuffer (GL_ARRAY_BUFFER, colours_vbo);
glVertexAttribPointer (1, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (0);
glEnableVertexAttribArray (1);
char vertex_shader[1024 * 256];
char geometry_shader[1024 * 256];
char fragment_shader[1024 * 256];
assert (parse_file_into_str ("test_vs.glsl", vertex_shader, 1024 * 256));
assert (parse_file_into_str ("test_gs.glsl", geometry_shader, 1024 * 256));
assert (parse_file_into_str ("test_fs.glsl", fragment_shader, 1024 * 256));
GLuint vs = glCreateShader (GL_VERTEX_SHADER);
const GLchar* p = (const GLchar*)vertex_shader;
glShaderSource (vs, 1, &p, NULL);
glCompileShader (vs);
// check for compile errors
int params = -1;
glGetShaderiv (vs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", vs);
print_shader_info_log (vs);
return 1; // or exit or something
}
// create geometry shader
GLuint gs = glCreateShader (GL_GEOMETRY_SHADER);
p = (const GLchar*)geometry_shader;
glShaderSource (gs, 1, &p, NULL);
glCompileShader (gs);
// check for compile errors
glGetShaderiv (gs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", gs);
print_shader_info_log (gs);
return 1; // or exit or something
}
GLuint fs = glCreateShader (GL_FRAGMENT_SHADER);
p = (const GLchar*)fragment_shader;
glShaderSource (fs, 1, &p, NULL);
glCompileShader (fs);
// check for compile errors
glGetShaderiv (fs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", fs);
print_shader_info_log (fs);
return 1; // or exit or something
}
GLuint shader_programme = glCreateProgram ();
glAttachShader (shader_programme, fs);
// attach geometry shader too
glAttachShader (shader_programme, gs);
glAttachShader (shader_programme, vs);
glLinkProgram (shader_programme);
glGetProgramiv (shader_programme, GL_LINK_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (
stderr,
"ERROR: could not link shader programme GL index %i\n",
shader_programme
);
print_programme_info_log (shader_programme);
return false;
}
assert (is_programme_valid (shader_programme));
glEnable (GL_CULL_FACE); // cull face
glCullFace (GL_BACK); // cull back face
glFrontFace (GL_CW); // GL_CCW for counter clock-wise
while (!glfwWindowShouldClose (g_window)) {
_update_fps_counter (g_window);
// wipe the drawing surface clear
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glViewport (0, 0, g_gl_width, g_gl_height);
glUseProgram (shader_programme);
glBindVertexArray (vao);
// points drawing mode
glDrawArrays (GL_POINTS, 0, 3);
// update other events like input handling
glfwPollEvents ();
if (GLFW_PRESS == glfwGetKey (g_window, GLFW_KEY_ESCAPE)) {
glfwSetWindowShouldClose (g_window, 1);
}
// put the stuff we've been drawing onto the display
glfwSwapBuffers (g_window);
}
// close GL context and any other GLFW resources
glfwTerminate();
return 0;
}
int main () {
assert (restart_gl_log ());
/*------------------------------start GL context------------------------------*/
assert (start_gl ());
/*------------------------------create geometry-------------------------------*/
GLfloat points[] = {
0.0f, 0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
-0.5f, -0.5f, 0.0f
};
GLfloat colours[] = {
1.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 1.0f
};
GLuint points_vbo;
glGenBuffers (1, &points_vbo);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glBufferData (GL_ARRAY_BUFFER, 9 * sizeof (GLfloat), points, GL_STATIC_DRAW);
GLuint colours_vbo;
glGenBuffers (1, &colours_vbo);
glBindBuffer (GL_ARRAY_BUFFER, colours_vbo);
glBufferData (GL_ARRAY_BUFFER, 9 * sizeof (GLfloat), colours, GL_STATIC_DRAW);
GLuint vao;
glGenVertexArrays (1, &vao);
glBindVertexArray (vao);
glBindBuffer (GL_ARRAY_BUFFER, points_vbo);
glVertexAttribPointer (0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glBindBuffer (GL_ARRAY_BUFFER, colours_vbo);
glVertexAttribPointer (1, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (0);
glEnableVertexAttribArray (1);
/*------------------------------create shaders--------------------------------*/
char vertex_shader[1024 * 256];
char fragment_shader[1024 * 256];
assert (parse_file_into_str ("Shaders/test_vs.glsl", vertex_shader, 1024 * 256));
assert (parse_file_into_str ("Shaders/test_fs.glsl", fragment_shader, 1024 * 256));
GLuint vs = glCreateShader (GL_VERTEX_SHADER);
const GLchar* p = (const GLchar*)vertex_shader;
glShaderSource (vs, 1, &p, NULL);
glCompileShader (vs);
// check for compile errors
int params = -1;
glGetShaderiv (vs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", vs);
print_shader_info_log (vs);
return 1; // or exit or something
}
GLuint fs = glCreateShader (GL_FRAGMENT_SHADER);
p = (const GLchar*)fragment_shader;
glShaderSource (fs, 1, &p, NULL);
glCompileShader (fs);
// check for compile errors
glGetShaderiv (fs, GL_COMPILE_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (stderr, "ERROR: GL shader index %i did not compile\n", fs);
print_shader_info_log (fs);
return 1; // or exit or something
}
GLuint shader_programme = glCreateProgram ();
glAttachShader (shader_programme, fs);
glAttachShader (shader_programme, vs);
glLinkProgram (shader_programme);
glGetProgramiv (shader_programme, GL_LINK_STATUS, ¶ms);
if (GL_TRUE != params) {
fprintf (
stderr,
"ERROR: could not link shader programme GL index %i\n",
shader_programme
);
print_programme_info_log (shader_programme);
return false;
}
/*--------------------------create camera matrices----------------------------*/
/* create PROJECTION MATRIX */
#define ONE_DEG_IN_RAD (2.0 * M_PI) / 360.0 // 0.017444444
// input variables
float near = 0.1f; // clipping plane
float far = 100.0f; // clipping plane
float fov = 67.0f * ONE_DEG_IN_RAD; // convert 67 degrees to radians
float aspect = (float)g_gl_width / (float)g_gl_height; // aspect ratio
// matrix components
float range = tan (fov * 0.5f) * near;
float Sx = (2.0f * near) / (range * aspect + range * aspect);
float Sy = near / range;
float Sz = -(far + near) / (far - near);
float Pz = -(2.0f * far * near) / (far - near);
GLfloat proj_mat[] = {
Sx, 0.0f, 0.0f, 0.0f,
0.0f, Sy, 0.0f, 0.0f,
0.0f, 0.0f, Sz, -1.0f,
0.0f, 0.0f, Pz, 0.0f
};
/* create VIEW MATRIX */
float cam_speed = 1.0f; // 1 unit per second
float cam_yaw_speed = 10.0f; // 10 degrees per second
float cam_pos[] = {0.0f, 0.0f, 2.0f}; // don't start at zero, or we will be too close
float cam_yaw = 0.0f; // y-rotation in degrees
mat4 T = translate (identity_mat4 (), vec3 (-cam_pos[0], -cam_pos[1], -cam_pos[2]));
mat4 R = rotate_y_deg (identity_mat4 (), -cam_yaw);
mat4 view_mat = R * T;
/* get location numbers of matrices in shader programme */
GLint view_mat_location = glGetUniformLocation (shader_programme, "view");
GLint proj_mat_location = glGetUniformLocation (shader_programme, "proj");
/* use program (make current in state machine) and set default matrix values*/
glUseProgram (shader_programme);
glUniformMatrix4fv (view_mat_location, 1, GL_FALSE, view_mat.m);
glUniformMatrix4fv (proj_mat_location, 1, GL_FALSE, proj_mat);
/*------------------------------rendering loop--------------------------------*/
/* some rendering defaults */
glEnable (GL_CULL_FACE); // cull face
glCullFace (GL_BACK); // cull back face
glFrontFace (GL_CW); // GL_CCW for counter clock-wise
while (!glfwWindowShouldClose (g_window)) {
static double previous_seconds = glfwGetTime ();
double current_seconds = glfwGetTime ();
double elapsed_seconds = current_seconds - previous_seconds;
previous_seconds = current_seconds;
_update_fps_counter (g_window);
// wipe the drawing surface clear
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glViewport (0, 0, g_gl_width, g_gl_height);
glUseProgram (shader_programme);
glBindVertexArray (vao);
// draw points 0-3 from the currently bound VAO with current in-use shader
glDrawArrays (GL_TRIANGLES, 0, 3);
// update other events like input handling
glfwPollEvents ();
/*-----------------------------move camera here-------------------------------*/
// control keys
bool cam_moved = false;
if (glfwGetKey (g_window, GLFW_KEY_A)) {
cam_pos[0] -= cam_speed * elapsed_seconds;
cam_moved = true;
}
if (glfwGetKey (g_window, GLFW_KEY_D)) {
cam_pos[0] += cam_speed * elapsed_seconds;
cam_moved = true;
}
if (glfwGetKey (g_window, GLFW_KEY_PAGE_UP)) {
cam_pos[1] += cam_speed * elapsed_seconds;
cam_moved = true;
}
if (glfwGetKey (g_window, GLFW_KEY_PAGE_DOWN)) {
cam_pos[1] -= cam_speed * elapsed_seconds;
cam_moved = true;
}
if (glfwGetKey (g_window, GLFW_KEY_W)) {
cam_pos[2] -= cam_speed * elapsed_seconds;
cam_moved = true;
}
if (glfwGetKey (g_window, GLFW_KEY_S)) {
cam_pos[2] += cam_speed * elapsed_seconds;
cam_moved = true;
}
if (glfwGetKey (g_window, GLFW_KEY_LEFT)) {
cam_yaw += cam_yaw_speed * elapsed_seconds;
cam_moved = true;
}
if (glfwGetKey (g_window, GLFW_KEY_RIGHT)) {
cam_yaw -= cam_yaw_speed * elapsed_seconds;
cam_moved = true;
}
/* update view matrix */
if (cam_moved) {
mat4 T = translate (identity_mat4 (), vec3 (-cam_pos[0], -cam_pos[1], -cam_pos[2])); // cam translation
mat4 R = rotate_y_deg (identity_mat4 (), -cam_yaw); //
mat4 view_mat = R * T;
glUniformMatrix4fv (view_mat_location, 1, GL_FALSE, view_mat.m);
}
if (GLFW_PRESS == glfwGetKey (g_window, GLFW_KEY_ESCAPE)) {
glfwSetWindowShouldClose (g_window, 1);
}
// put the stuff we've been drawing onto the display
glfwSwapBuffers (g_window);
}
// close GL context and any other GLFW resources
glfwTerminate();
return 0;
}
