matrix_4x4 m44_view_look_at(vector3 position, vector3 target, vector3 up) {
/*
Taken From:
http://www.opengl.org/wiki/GluLookAt_code
*/
vector3 zaxis = v3_normalize( v3_sub(target, position) );
vector3 xaxis = v3_normalize( v3_cross(up, zaxis) );
vector3 yaxis = v3_cross(zaxis, xaxis);
matrix_4x4 view_matrix = m44_id();
view_matrix.xx = xaxis.x;
view_matrix.xy = xaxis.y;
view_matrix.xz = xaxis.z;
view_matrix.yx = yaxis.x;
view_matrix.yy = yaxis.y;
view_matrix.yz = yaxis.z;
view_matrix.zx = -zaxis.x;
view_matrix.zy = -zaxis.y;
view_matrix.zz = -zaxis.z;
// Also unsure of this.
view_matrix = m44_mul_m44(view_matrix, m44_translation(v3_neg(position)) );
return view_matrix;
}
mat4_t mat4_look_at(v3_t eye, v3_t center, v3_t up) {
v3_t fwd = { center.x - eye.x, center.y - eye.y, center.z - eye.z };
fwd = v3_normalize(fwd);
v3_t right = v3_normalize(v3_cross(fwd, up));
up = v3_normalize(v3_cross(right, fwd));
mat4_t v;
v.m11 = right.x;
v.m12 = right.y;
v.m13 = right.z;
v.m14 = -v3_scalar(right, eye);
v.m21 = up.x;
v.m22 = up.y;
v.m23 = up.z;
v.m24 = -v3_scalar(up, eye);
v.m31 = -fwd.x;
v.m32 = -fwd.y;
v.m33 = -fwd.z;
v.m34 = v3_scalar(fwd, eye);
v.m41 = 0.f;
v.m42 = 0.f;
v.m43 = 0.f;
v.m44 = 1.f;
return v;
}
void scotland_update() {
camera* cam = entity_get("camera");
light* sun = entity_get("sun");
static_object* skydome = entity_get("skydome");
landscape* world = entity_get("world");
sun_orbit += frame_time() * 0.01;
sun->position.x = 512 + sin(sun_orbit) * 512;
sun->position.y = cos(sun_orbit) * 512;
sun->position.z = 512;
sun->target = v3(512, 0, 512);
if (w_held || s_held) {
vector3 cam_dir = v3_normalize(v3_sub(cam->target, cam->position));
float speed = 0.5;
if (!freecam) speed = 0.05;
if (w_held) {
cam->position = v3_add(cam->position, v3_mul(cam_dir, speed));
}
if (s_held) {
cam->position = v3_sub(cam->position, v3_mul(cam_dir, speed));
}
if (!freecam) {
float height = terrain_height(world->terrain, v2(cam->position.x, cam->position.z));
cam->position.y = height + 1;
}
cam->target = v3_add(cam->position, cam_dir);
}
Uint8 keystate = SDL_GetMouseState(NULL, NULL);
if(keystate & SDL_BUTTON(1)){
float a1 = -(float)mouse_x * 0.005;
float a2 = (float)mouse_y * 0.005;
vector3 cam_dir = v3_normalize(v3_sub(cam->target, cam->position));
cam_dir.y += -a2;
vector3 side_dir = v3_normalize(v3_cross(cam_dir, v3(0,1,0)));
cam_dir = v3_add(cam_dir, v3_mul(side_dir, -a1));
cam_dir = v3_normalize(cam_dir);
cam->target = v3_add(cam->position, cam_dir);
}
mouse_x = 0;
mouse_y = 0;
ui_button* framerate = ui_elem_get("framerate");
ui_button_set_label(framerate, frame_rate_string());
}
t_vec3 v3_frontnormed(float const a[2])
{
return (v3_normalize(ATOV3(
cos(a[0]) * cos(a[1])
, sin(a[1])
, sin(a[0]) * cos(a[1]))));
}
/* Adds a triangle by interpolating over the given edges (which are expected to
* contain an intersection).
* The edges are specified by their vertices (u is the first edge, v the second,
* etc.)
*/
void interpolate_edges(triangle *triangles, unsigned char isovalue, cell c,
int u0, int u1,
int v0, int v1,
int w0, int w1)
{
vec3 p1, p2, p3;
p1 = interpolate_points(isovalue, c.p[u0], c.p[u1], c.value[u0], c.value[u1]);
p2 = interpolate_points(isovalue, c.p[v0], c.p[v1], c.value[v0], c.value[v1]);
p3 = interpolate_points(isovalue, c.p[w0], c.p[w1], c.value[w0], c.value[w1]);
triangles->p[0] = p1;
triangles->p[1] = p2;
triangles->p[2] = p3;
// the surface-normal is the cross-product between 2 of the edges making up
// the face
vec3 normal = v3_crossprod(v3_subtract(p1, p2),
v3_subtract(p3, p1));
normal = v3_normalize(normal);
normal = v3_multiply(normal, -1);
triangles->n[0] = normal;
triangles->n[1] = normal;
triangles->n[2] = normal;
}
static void toggle_freecam(ui_button* b, SDL_Event event) {
if (event.type == SDL_MOUSEBUTTONDOWN) {
if (ui_button_contains_position(b, v2(event.motion.x, event.motion.y))) {
b->pressed = true;
}
} else if (event.type == SDL_MOUSEBUTTONUP) {
if (b->pressed) {
b->pressed = false;
freecam = !freecam;
camera* cam = entity_get("camera");
landscape* world = entity_get("world");
vector3 cam_dir = v3_normalize(v3_sub(cam->target, cam->position));
float height = terrain_height(world->terrain, v2(cam->position.x, cam->position.z));
cam->position.y = height + 1;
cam->target = v3_add(cam->position, cam_dir);
}
}
}
void
triangle_update(triangle_t* triangle)
{
v3_sub(&triangle->edge1, &triangle->v1, &triangle->v0);
v3_sub(&triangle->edge2, &triangle->v2, &triangle->v0);
v3_cross(&triangle->normal, &triangle->edge1, &triangle->edge2);
v3_normalize(&triangle->normal);
}
void metaballs_event(SDL_Event event) {
camera* cam = entity_get("camera");
light* sun = entity_get("sun");
switch(event.type){
case SDL_KEYDOWN:
break;
case SDL_KEYUP:
if (event.key.keysym.sym == SDLK_SPACE) {
particles_reset();
}
if (event.key.keysym.sym == SDLK_w) {
wireframe = !wireframe;
}
break;
case SDL_MOUSEBUTTONUP:
break;
case SDL_MOUSEBUTTONDOWN:
if (event.button.button == SDL_BUTTON_WHEELUP) {
cam->position = v3_sub(cam->position, v3_normalize(v3_sub(cam->position, cam->target)));
}
if (event.button.button == SDL_BUTTON_WHEELDOWN) {
cam->position = v3_add(cam->position, v3_normalize(v3_sub(cam->position, cam->target)));
}
break;
case SDL_MOUSEMOTION:
mouse_x = event.motion.xrel;
mouse_y = event.motion.yrel;
break;
}
}
// Check if the given sphere is intersected by the given ray.
// See Shirley et.al., section 10.3.1
// Returns 1 if there is an intersection (and sets the appropriate
// fields of ip), or 0 otherwise.
static int
ray_intersects_sphere(intersection_point* ip, sphere sph,
vec3 ray_origin, vec3 ray_direction)
{
float A, B, C, D;
vec3 diff;
float t_hit;
A = v3_dotprod(ray_direction, ray_direction);
diff = v3_subtract(ray_origin, sph.center);
B = 2.0 * v3_dotprod(diff, ray_direction);
C = v3_dotprod(diff, diff) - sph.radius * sph.radius;
D = B*B - 4*A*C;
if (D < 0.0)
return 0;
D = sqrt(D);
// We're only interested in the first hit, i.e. the one with
// the smallest t_hit, so we check -B-D first, followed by -B+D
t_hit = (-B - D)/(2*A);
if (t_hit < 0.0)
{
t_hit = (-B + D)/(2*A);
if (t_hit < 0.0)
return 0;
}
ip->t = t_hit;
ip->p = v3_add(ray_origin, v3_multiply(ray_direction, t_hit));
ip->n = v3_normalize(v3_subtract(ip->p, sph.center));
ip->i = v3_normalize(v3_negate(ray_direction));
ip->material = sph.material;
return 1;
}
void sea_event(SDL_Event event) {
camera* cam = entity_get("camera");
light* sun = entity_get("sun");
switch(event.type) {
case SDL_KEYUP:
if (event.key.keysym.sym == SDLK_SPACE) {
char ball_name[20];
sprintf(ball_name, "ball_%i", ball_count);
ball_count++;
physics_object* ball = entity_new(ball_name, physics_object);
ball->renderable = asset_get("./resources/ball.obj");
ball->collision_body = collision_body_new_sphere(sphere_new(v3_zero(), 1));
ball->position = cam->position;
ball->scale = v3(0.5, 0.5, 0.5);
ball->velocity = v3_mul(v3_normalize(v3_sub(cam->target, cam->position)), 75);
}
case SDL_MOUSEBUTTONDOWN:
if (event.button.button == SDL_BUTTON_WHEELUP) {
cam->position = v3_sub(cam->position, v3_normalize(cam->position));
}
if (event.button.button == SDL_BUTTON_WHEELDOWN) {
cam->position = v3_add(cam->position, v3_normalize(cam->position));
}
break;
case SDL_MOUSEMOTION:
mouse_x = event.motion.xrel;
mouse_y = event.motion.yrel;
break;
}
}
void sea_update() {
camera* cam = entity_get("camera");
light* sun = entity_get("sun");
wave_time += frame_time();
static_object* corvette = entity_get("corvette");
corvette->position.y = (sin(wave_time) + 1) / 2;
corvette->rotation = v4_quaternion_pitch(sin(wave_time * 1.123) / 50);
corvette->rotation = v4_quaternion_mul(corvette->rotation, v4_quaternion_yaw(sin(wave_time * 1.254) / 25));
corvette->rotation = v4_quaternion_mul(corvette->rotation, v4_quaternion_roll(sin(wave_time * 1.355) / 100));
static_object* center_sphere = entity_get("center_sphere");
physics_object* balls[100];
int num_balls;
entities_get(balls, &num_balls, physics_object);
for(int i = 0; i < num_balls; i++) {
physics_object_collide_static(balls[i], center_sphere, frame_time());
physics_object_collide_static(balls[i], corvette, frame_time());
physics_object_update(balls[i], frame_time());
}
Uint8 keystate = SDL_GetMouseState(NULL, NULL);
if(keystate & SDL_BUTTON(1)) {
float a1 = -(float)mouse_x * 0.01;
float a2 = (float)mouse_y * 0.01;
cam->position = v3_sub(cam->position, cam->target);
cam->position = m33_mul_v3(m33_rotation_y( a1 ), cam->position );
cam->position = v3_add(cam->position, cam->target);
cam->position = v3_sub(cam->position, cam->target);
vector3 rotation_axis = v3_normalize(v3_cross( v3_sub(cam->position, v3_zero()) , v3(0,1,0) ));
cam->position = m33_mul_v3(m33_rotation_axis_angle(rotation_axis, a2 ), cam->position );
cam->position = v3_add(cam->position, cam->target);
}
if(keystate & SDL_BUTTON(3)) {
sun->position.x += (float)mouse_y / 2;
sun->position.z -= (float)mouse_x / 2;
}
mouse_x = 0;
mouse_y = 0;
ui_button* framerate = ui_elem_get("framerate");
ui_button_set_label(framerate, frame_rate_string());
}
void metaballs_update() {
camera* cam = entity_get("camera");
light* sun = entity_get("sun");
Uint8 keystate = SDL_GetMouseState(NULL, NULL);
if(keystate & SDL_BUTTON(1)){
float a1 = -(float)mouse_x * frame_time() * 0.25;
float a2 = (float)mouse_y * frame_time() * 0.25;
cam->position = v3_sub(cam->position, cam->target);
cam->position = m33_mul_v3(m33_rotation_y( a1 ), cam->position );
cam->position = v3_add(cam->position, cam->target);
cam->position = v3_sub(cam->position, cam->target);
vector3 rotation_axis = v3_normalize(v3_cross( v3_sub(cam->position, v3_zero()) , v3(0,1,0) ));
cam->position = m33_mul_v3(m33_rotation_axis_angle(rotation_axis, a2 ), cam->position );
cam->position = v3_add(cam->position, cam->target);
}
if(keystate & SDL_BUTTON(3)){
sun->position.x += (float)mouse_y / 2;
sun->position.z -= (float)mouse_x / 2;
}
mouse_x = 0;
mouse_y = 0;
particles_update(frame_time());
ui_button* framerate = ui_elem_get("framerate");
ui_button_set_label(framerate, frame_rate_string());
#ifdef MARCHING_CUBES
marching_cubes_metaball_data( particle_positions_memory(), particles_count() );
marching_cubes_clear();
marching_cubes_update();
#endif
#ifdef VOLUME_RENDERER
volume_renderer_metaball_data( particle_positions_memory(), particles_count() );
volume_renderer_update();
#endif
}
void setcameraview(camera c, float aspectratio)
{
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(c.fov,aspectratio,0.1,500.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
//glRotatef(1,1,1,(float)c.roll*360.0f/255.0f);
vector3 dir=v3_normalize(v3_sub(c.target,c.eye));
matrix m;
m_rotate(dir.x,dir.y,dir.z,(float)c.roll*360.0f/255.0f*(float)radtheta,m);
vector3 u;
m_xformd(m,c.up,u);
gluLookAt(c.eye.x,c.eye.y,c.eye.z,
c.target.x,c.target.y,c.target.z,
u.x,u.y,u.z);
glGetFloatv(GL_MODELVIEW_MATRIX,cam);
}
void m_rotate(float ax,float ay,float az,float phi,matrix &m)
{
matrix m1;
vector a;
if (ax==0 && ay==0 && az==0) {m_identity(m); return;}
v3_make(ax, ay, az, a);
v3_normalize(a, a);
m_identity(m);
m_mults(m, (float)cos(phi), m);
m_diadic3(a, a, m1);
m_mults(m1, (float)(1-cos(phi)), m1);
m_add(m, m1, m);
m_cross(a, m1);
m_mults(m1, (float)sin(phi), m1);
m_add(m, m1, m);
m[3][3] = 1.0;
}
static void init_noise()
{
int i;
/* calculate random gradients */
for(i=0; i<B; i++) {
perm[i] = i; /* .. and initialize permutation mapping to identity */
grad1[i] = (scalar_t)((rand() % (B + B)) - B) / B;
grad2[i].x = (scalar_t)((rand() % (B + B)) - B) / B;
grad2[i].y = (scalar_t)((rand() % (B + B)) - B) / B;
grad2[i] = v2_normalize(grad2[i]);
grad3[i].x = (scalar_t)((rand() % (B + B)) - B) / B;
grad3[i].y = (scalar_t)((rand() % (B + B)) - B) / B;
grad3[i].z = (scalar_t)((rand() % (B + B)) - B) / B;
grad3[i] = v3_normalize(grad3[i]);
}
/* permute indices by swapping them randomly */
for(i=0; i<B; i++) {
int rand_idx = rand() % B;
int tmp = perm[i];
perm[i] = perm[rand_idx];
perm[rand_idx] = tmp;
}
/* fill up the rest of the arrays by duplicating the existing gradients */
/* and permutations */
for(i=0; i<B+2; i++) {
perm[B + i] = perm[i];
grad1[B + i] = grad1[i];
grad2[B + i] = grad2[i];
grad3[B + i] = grad3[i];
}
}
vector3 light_direction(light* l) {
return v3_normalize( v3_sub( l->target, l->position ) );
}
void
ray_trace(void)
{
vec3 forward_vector, right_vector, up_vector;
int i, j;
float image_plane_width, image_plane_height;
vec3 color;
char buf[128];
struct timeval t0, t1;
float time_taken;
fprintf(stderr, "Ray tracing ...");
gettimeofday(&t0, NULL);
num_rays_shot = num_shadow_rays_shot = num_triangles_tested = num_bboxes_tested = 0;
// Compute camera coordinate system from camera position
// and look-at point
up_vector = v3_create(0, 0, 1);
forward_vector = v3_normalize(v3_subtract(scene_camera_lookat, scene_camera_position));
right_vector = v3_normalize(v3_crossprod(forward_vector, up_vector));
up_vector = v3_crossprod(right_vector, forward_vector);
// Compute size of image plane from the chosen field-of-view
// and image aspect ratio. This is the size of the plane at distance
// of one unit from the camera position.
image_plane_height = 2.0 * tan(0.5*VFOV/180*M_PI);
image_plane_width = image_plane_height * (1.0 * framebuffer_width / framebuffer_height);
float bottom, left, Us, Vs;
left = -image_plane_width * 0.5;
bottom = image_plane_height * 0.5;
fprintf(stderr, "%d %d\r\n", framebuffer_height, framebuffer_width);
// Loop over all pixels in the framebuffer
for (j = 0; j < framebuffer_height; j++)
{
for (i = 0; i < framebuffer_width; i++)
{
if(!do_antialiasing){
/* With the formula "b + (t−b) * ((j+ 0.5) / ny)" the vector is calculated.
* (t-b) equals the negative image_plane_height
*/
Us = bottom + (-image_plane_height*(j+0.5)/framebuffer_height);
/* using the formula: "l + (r−l) * ((i+ 0.5) / nx)" to calculate the vector
* (r-l) equals the image_plane_width.
*/
Vs = left + (image_plane_width*(i+0.5)/framebuffer_width);
/*
/* Calculate the vector through the pixel (for "Ray through pixel")
* Using the formula "Us * U + Vs * v + n * w"
*/
vec3 UV = v3_add(v3_multiply(up_vector, Us), v3_multiply(right_vector, Vs));
vec3 ray = v3_add(forward_vector, UV);
/* Fills the color */
color = ray_color(0, scene_camera_position, ray);
} else {
float Us1 = bottom + (-image_plane_height*(j+0.25)/framebuffer_height);
float Us2 = bottom + (-image_plane_height*(j+0.75)/framebuffer_height);
float Vs1 = left + (image_plane_width*(i+0.25)/framebuffer_width);
float Vs2 = left + (image_plane_width*(i+0.75)/framebuffer_width);
vec3 UV1 = v3_add(v3_multiply(up_vector, Us1), v3_multiply(right_vector, Vs1));
vec3 UV2 = v3_add(v3_multiply(up_vector, Us2), v3_multiply(right_vector, Vs1));
vec3 UV3 = v3_add(v3_multiply(up_vector, Us1), v3_multiply(right_vector, Vs2));
vec3 UV4 = v3_add(v3_multiply(up_vector, Us2), v3_multiply(right_vector, Vs2));
vec3 color1 = ray_color(0, scene_camera_position, v3_add(forward_vector, UV1));
vec3 color2 = ray_color(0, scene_camera_position, v3_add(forward_vector, UV2));
vec3 color3 = ray_color(0, scene_camera_position, v3_add(forward_vector, UV3));
vec3 color4 = ray_color(0, scene_camera_position, v3_add(forward_vector, UV4));
color = v3_multiply( v3_add(v3_add(color1, color2), v3_add(color3, color4)), 0.25 );
}
/* Output pixel color */
put_pixel(i, j, color.x, color.y, color.z);
}
sprintf(buf, "Ray-tracing ::: %.0f%% done", 100.0*j/framebuffer_height);
glutSetWindowTitle(buf);
}
// Done!
gettimeofday(&t1, NULL);
glutSetWindowTitle("Ray-tracing ::: done");
// Output some statistics
time_taken = 1.0 * (t1.tv_sec - t0.tv_sec) + (t1.tv_usec - t0.tv_usec) / 1000000.0;
fprintf(stderr, " done in %.1f seconds\n", time_taken);
fprintf(stderr, "... %lld total rays shot, of which %d camera rays and "
"%lld shadow rays\n", num_rays_shot,
do_antialiasing ? 4*framebuffer_width*framebuffer_height :
framebuffer_width*framebuffer_height,
num_shadow_rays_shot);
fprintf(stderr, "... %lld triangles intersection tested "
"(avg %.1f tri/ray)\n",
num_triangles_tested, 1.0*num_triangles_tested/num_rays_shot);
fprintf(stderr, "... %lld bboxes intersection tested (avg %.1f bbox/ray)\n",
num_bboxes_tested, 1.0*num_bboxes_tested/num_rays_shot);
}
void particles_init() {
particle_positions = malloc(sizeof(vector4) * particle_count);
particle_velocities = malloc(sizeof(vector4) * particle_count);
particle_lifetimes = malloc(sizeof(float) * particle_count);
particle_randoms = malloc(sizeof(vector4) * particle_count);
srand(time(NULL));
for(int i = 0; i < particle_count; i++) {
particle_lifetimes[i] = 999;
particle_positions[i] = v4(0,0,0,0);
particle_velocities[i] = v4(0,0,0,0);
float rx = ((float)rand() / RAND_MAX) * 2 - 1;
float ry = ((float)rand() / RAND_MAX) * 2 + 0.5;
float rz = ((float)rand() / RAND_MAX) * 2 - 1;
float rm = (float)rand() / RAND_MAX;
vector3 rand = v3_mul(v3_normalize(v3(rx, ry, rz)), rm * 2);
particle_randoms[i] = v4(rand.x, rand.y, rand.z, 0);
}
glGenBuffers(1, &positions_buffer);
glBindBuffer(GL_ARRAY_BUFFER, positions_buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(vector4) * particle_count, particle_positions, GL_DYNAMIC_COPY);
glGenBuffers(1, &velocities_buffer);
glBindBuffer(GL_ARRAY_BUFFER, velocities_buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(vector4) * particle_count, particle_velocities, GL_DYNAMIC_COPY);
glGenBuffers(1, &lifetimes_buffer);
glBindBuffer(GL_ARRAY_BUFFER, lifetimes_buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(float) * particle_count, particle_lifetimes, GL_DYNAMIC_COPY);
glGenBuffers(1, &randoms_buffer);
glBindBuffer(GL_ARRAY_BUFFER, randoms_buffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(vector4) * particle_count, particle_randoms, GL_DYNAMIC_COPY);
#ifdef OPEN_GL_CPU
#ifndef CPU_ONLY
k_particle_positions = kernel_memory_allocate(sizeof(vector4) * particle_count);
k_particle_velocities = kernel_memory_allocate(sizeof(vector4) * particle_count);
k_particle_lifetimes = kernel_memory_allocate(sizeof(float) * particle_count);
k_particle_randoms = kernel_memory_allocate(sizeof(vector4) * particle_count);
kernel_memory_write(k_particle_positions, sizeof(vector4) * particle_count, particle_positions);
kernel_memory_write(k_particle_velocities, sizeof(vector4) * particle_count, particle_velocities);
kernel_memory_write(k_particle_lifetimes, sizeof(float) * particle_count, particle_lifetimes);
kernel_memory_write(k_particle_randoms, sizeof(vector4) * particle_count, particle_randoms);
#endif
#else
k_particle_positions = kernel_memory_from_glbuffer(positions_buffer);
k_particle_velocities = kernel_memory_from_glbuffer(velocities_buffer);
k_particle_lifetimes = kernel_memory_from_glbuffer(lifetimes_buffer);
k_particle_randoms = kernel_memory_from_glbuffer(randoms_buffer);
#endif
kernel_program* program = asset_get("./kernels/particles.cl");
float max_life = 60.0;
float min_velocity = 0.5;
#ifndef CPU_ONLY
k_update = kernel_program_get_kernel(program, "particle_update");
kernel_set_argument(k_update, 0, sizeof(kernel_memory), &k_particle_positions);
kernel_set_argument(k_update, 1, sizeof(kernel_memory), &k_particle_velocities);
kernel_set_argument(k_update, 2, sizeof(kernel_memory), &k_particle_lifetimes);
kernel_set_argument(k_update, 3, sizeof(kernel_memory), &k_particle_randoms);
kernel_set_argument(k_update, 4, sizeof(cl_float), &max_life);
kernel_set_argument(k_update, 5, sizeof(cl_float), &min_velocity);
kernel_set_argument(k_update, 9, sizeof(cl_int), &particle_count);
#endif
}
void
ray_trace(void)
{
vec3 forward_vector, right_vector, up_vector;
int i, j;
float image_plane_width, image_plane_height;
vec3 color;
char buf[128];
struct timeval t0, t1;
float time_taken;
fprintf(stderr, "Ray tracing ...");
gettimeofday(&t0, NULL);
num_rays_shot = num_shadow_rays_shot = num_triangles_tested = num_bboxes_tested = 0;
// Compute camera coordinate system from camera position
// and look-at point
up_vector = v3_create(0, 0, 1);
forward_vector = v3_normalize(v3_subtract(scene_camera_lookat, scene_camera_position));
right_vector = v3_normalize(v3_crossprod(forward_vector, up_vector));
up_vector = v3_crossprod(right_vector, forward_vector);
// Compute size of image plane from the chosen field-of-view
// and image aspect ratio. This is the size of the plane at distance
// of one unit from the camera position.
image_plane_height = 2.0 * tan(0.5*VFOV/180*M_PI);
image_plane_width = image_plane_height * (1.0 * framebuffer_width / framebuffer_height);
// vector points to the middle of the monitor
vec3 plane_center = v3_add(scene_camera_position, forward_vector);
// vector points to the left side of the monitor
vec3 le_unnormalized = v3_multiply(right_vector, -(image_plane_width / 2.0));
// vector points to the up side of the monitor
vec3 up_unnormalized = v3_multiply(up_vector, image_plane_height / 2.0);
// vector points to the coordinates 0,0 (left up) of the monitor
vec3 left_up = v3_add(plane_center, v3_add(le_unnormalized, up_unnormalized));
// vector points to right, and has length equal to width of a pixel
vec3 pixel2pixel_x = v3_multiply(right_vector, (image_plane_width / framebuffer_width));
// vector points to down, and has length equal to height of a pixel
vec3 pixel2pixel_y = v3_multiply(up_vector, -(image_plane_height / framebuffer_height));
// ANTI-ALIASING LOOP
if (do_antialiasing) {
// loop over all pixels in the framebuffer
for (j = 0; j < framebuffer_height; j++) {
for (i = 0; i < framebuffer_width; i++) {
// for each pixel, shoot four rays
vec3 ray_direction_00 = v3_add(v3_add(left_up, v3_multiply(pixel2pixel_y, j + 0.25)), v3_multiply(pixel2pixel_x, i + 0.25));
vec3 ray_direction_01 = v3_add(v3_add(left_up, v3_multiply(pixel2pixel_y, j + 0.75)), v3_multiply(pixel2pixel_x, i + 0.25));
vec3 ray_direction_10 = v3_add(v3_add(left_up, v3_multiply(pixel2pixel_y, j + 0.25)), v3_multiply(pixel2pixel_x, i + 0.75));
vec3 ray_direction_11 = v3_add(v3_add(left_up, v3_multiply(pixel2pixel_y, j + 0.75)), v3_multiply(pixel2pixel_x, i + 0.75));
// for each ray fired, get the difference
ray_direction_00 = v3_subtract(ray_direction_00, scene_camera_position);
ray_direction_01 = v3_subtract(ray_direction_01, scene_camera_position);
ray_direction_10 = v3_subtract(ray_direction_10, scene_camera_position);
ray_direction_11 = v3_subtract(ray_direction_11, scene_camera_position);
// add the colors of the four rays, then divide by four
color = ray_color(0, scene_camera_position, ray_direction_00);
color = v3_add(color, ray_color(0, scene_camera_position, ray_direction_01));
color = v3_add(color, ray_color(0, scene_camera_position, ray_direction_10));
color = v3_add(color, ray_color(0, scene_camera_position, ray_direction_11));
color = v3_multiply(color, 0.25);
// output pixel color
put_pixel(i, j, color.x, color.y, color.z);
}
sprintf(buf, "Ray-tracing (AA enabled) ::: %.0f%% done", 100.0*j/framebuffer_height);
glutSetWindowTitle(buf);
}
}
// NON-ANTI-ALIASING LOOP
else {
// loop over all pixels in the framebuffer
for (j = 0; j < framebuffer_height; j++) {
for (i = 0; i < framebuffer_width; i++) {
// select the currently relevant pixel
vec3 ray_direction = v3_add(v3_add(left_up, v3_multiply(pixel2pixel_y, j + 0.5)), v3_multiply(pixel2pixel_x, i + 0.5));
// get diference between the two points
ray_direction = v3_subtract(ray_direction, scene_camera_position);
// set color
color = ray_color(0, scene_camera_position, ray_direction);
// output pixel color
put_pixel(i, j, color.x, color.y, color.z);
}
sprintf(buf, "Ray-tracing ::: %.0f%% done", 100.0*j/framebuffer_height);
glutSetWindowTitle(buf);
}
}
// set a detailed title, useful for testing
if (use_bvh && do_antialiasing)
glutSetWindowTitle("Ray-tracing is done. AA=yes, BVH=yes");
else if (use_bvh && !do_antialiasing)
glutSetWindowTitle("Ray-tracing is done. AA=no, BVH=yes");
else if (!use_bvh && do_antialiasing)
glutSetWindowTitle("Ray-tracing is done. AA=yes, BVH=no");
else
glutSetWindowTitle("Ray-tracing is done. AA=no, BVH=no");
// Done!
gettimeofday(&t1, NULL);
// Output some statistics
time_taken = 1.0 * (t1.tv_sec - t0.tv_sec) + (t1.tv_usec - t0.tv_usec) / 1000000.0;
fprintf(stderr, " done in %.1f seconds\n", time_taken);
fprintf(stderr, "... %d total rays shot, of which %d camera rays and %d shadow rays\n",
num_rays_shot,
do_antialiasing ? 4*framebuffer_width*framebuffer_height : framebuffer_width*framebuffer_height,
num_shadow_rays_shot);
fprintf(stderr, "... %d triangles intersection tested (avg %.1f tri/ray)\n",
num_triangles_tested, 1.0*num_triangles_tested/num_rays_shot);
fprintf(stderr, "... %d bboxes intersection tested (avg %.1f bbox/ray)\n",
num_bboxes_tested, 1.0*num_bboxes_tested/num_rays_shot);
}
static int
ray_intersects_triangle(intersection_point* ip, triangle tri,
vec3 ray_origin, vec3 ray_direction)
{
vec3 edge1, edge2;
vec3 tvec, pvec, qvec;
double det, inv_det;
double t, u, v; // u, v are barycentric coordinates
// t is ray parameter
num_triangles_tested++;
edge1 = v3_subtract(scene_vertices[tri.v[1]], scene_vertices[tri.v[0]]);
edge2 = v3_subtract(scene_vertices[tri.v[2]], scene_vertices[tri.v[0]]);
pvec = v3_crossprod(ray_direction, edge2);
det = v3_dotprod(edge1, pvec);
if (det < 1.0e-6)
return 0;
tvec = v3_subtract(ray_origin, scene_vertices[tri.v[0]]);
u = v3_dotprod(tvec, pvec);
if (u < 0.0 || u > det)
return 0;
qvec = v3_crossprod(tvec, edge1);
v = v3_dotprod(ray_direction, qvec);
if (v < 0.0 || u+v > det)
return 0;
t = v3_dotprod(edge2, qvec);
if (t < 0.0)
return 0;
inv_det = 1.0 / det;
t *= inv_det;
u *= inv_det;
v *= inv_det;
// We have a triangle intersection!
// Return the relevant intersection values.
// Compute the actual intersection point
ip->t = t;
ip->p = v3_add(ray_origin, v3_multiply(ray_direction, t));
// Compute an interpolated normal for this intersection point, i.e.
// we use the barycentric coordinates as weights for the vertex normals
ip->n = v3_normalize(v3_add(
v3_add(
v3_multiply(tri.vn[0], 1.0-u-v),
v3_multiply(tri.vn[1], u)
),
v3_multiply(tri.vn[2], v)));
ip->i = v3_normalize(v3_negate(ray_direction));
ip->material = tri.material;
return 1;
}
void
ray_trace(void)
{
vec3 forward_vector, right_vector, up_vector;
int i, j;
float image_plane_width, image_plane_height;
vec3 color;
char buf[128];
struct timeval t0, t1;
float time_taken;
fprintf(stderr, "Ray tracing ...");
gettimeofday(&t0, NULL);
num_rays_shot = num_shadow_rays_shot = num_triangles_tested = num_bboxes_tested = 0;
// Compute camera coordinate system from camera position
// and look-at point
up_vector = v3_create(0, 0, 1);
forward_vector = v3_normalize(v3_subtract(scene_camera_lookat, scene_camera_position));
right_vector = v3_normalize(v3_crossprod(forward_vector, up_vector));
up_vector = v3_crossprod(right_vector, forward_vector);
// Compute size of image plane from the chosen field-of-view
// and image aspect ratio. This is the size of the plane at distance
// of one unit from the camera position.
image_plane_height = 2.0 * tan(0.5*VFOV/180*M_PI);
image_plane_width = image_plane_height * (1.0 * framebuffer_width / framebuffer_height);
printf("imageplane: (%f, %f)\n", image_plane_width, image_plane_height);
// the borders of the image plane in camera coordinates
float left = -(image_plane_width / 2),
right = image_plane_width / 2,
bottom = (image_plane_height / 2),
top = -image_plane_height / 2;
// rays are expressed as a location vector and direction vector
vec3 ray_origin = scene_camera_position;
float u, v, w;
// Loop over all pixels in the framebuffer
for (j = 0; j < framebuffer_height; j++)
{
for (i = 0; i < framebuffer_width; i++)
{
vec3 directions[4];
int directions_i = 0;
float offsets[2];
int offsets_n;
// if anti-aliasing is activated, shoot 4 rays through each pixel
// slightly offset from the center
if (do_antialiasing) {
offsets_n = 2;
offsets[0] = 0.25;
offsets[1] = 0.75;
}
// without anti-aliasing, just send a single ray through the
// pixel-center
else {
offsets_n = 1;
offsets[0] = 0.5;
}
// calculate the [u, v, w] components of the pixel's location
// relative to the camera
for (int u_offset = 0; u_offset < offsets_n; ++u_offset) {
for (int v_offset = 0; v_offset < offsets_n; ++v_offset) {
w = 1;
u = left + (right - left) * (i + offsets[u_offset]) / framebuffer_width;
v = bottom + (top - bottom) * (j + offsets[v_offset]) / framebuffer_height;
// the direction of the ray is a a linear combination of the camera
// basisvectors
directions[directions_i] = v3_add3(v3_multiply(forward_vector, w),
v3_multiply(right_vector, u),
v3_multiply(up_vector, v));
directions_i += 1;
}
}
// Output average pixel color
color = v3_create(0.0, 0.0, 0.0);
int num_directions = do_antialiasing ? 2 * offsets_n : 1;
for (int dir = 0; dir < num_directions; ++dir) {
color = v3_add(color, ray_color(0, ray_origin, directions[dir]) );
}
color = v3_multiply(color, 1.0 / num_directions);
put_pixel(i, j, color.x, color.y, color.z);
}
sprintf(buf, "Ray-tracing ::: %.0f%% done", 100.0*j/framebuffer_height);
glutSetWindowTitle(buf);
}
// Done!
gettimeofday(&t1, NULL);
glutSetWindowTitle("Ray-tracing ::: done");
// Output some statistics
time_taken = 1.0 * (t1.tv_sec - t0.tv_sec) + (t1.tv_usec - t0.tv_usec) / 1000000.0;
fprintf(stderr, " done in %.1f seconds\n", time_taken);
fprintf(stderr, "... %d total rays shot, of which %d camera rays and %d shadow rays\n",
num_rays_shot,
do_antialiasing ? 4*framebuffer_width*framebuffer_height : framebuffer_width*framebuffer_height,
num_shadow_rays_shot);
fprintf(stderr, "... %d triangles intersection tested (avg %.1f tri/ray)\n",
num_triangles_tested, 1.0*num_triangles_tested/num_rays_shot);
fprintf(stderr, "... %d bboxes intersection tested (avg %.1f bbox/ray)\n",
num_bboxes_tested, 1.0*num_bboxes_tested/num_rays_shot);
}
void
ray_trace(void)
{
vec3 forward_vector, right_vector, up_vector;
int i, j;
float image_plane_width, image_plane_height;
vec3 color;
char buf[128];
struct timeval t0, t1;
float time_taken;
fprintf(stderr, "Ray tracing ...");
gettimeofday(&t0, NULL);
num_rays_shot = num_shadow_rays_shot = num_triangles_tested = num_bboxes_tested = 0;
// Compute camera coordinate system from camera position
// and look-at point
up_vector = v3_create(0, 0, 1);
forward_vector = v3_normalize(v3_subtract(scene_camera_lookat, scene_camera_position));
right_vector = v3_normalize(v3_crossprod(forward_vector, up_vector));
up_vector = v3_crossprod(right_vector, forward_vector);
// Compute size of image plane from the chosen field-of-view
// and image aspect ratio. This is the size of the plane at distance
// of one unit from the camera position.
image_plane_height = 2.0 * tan(0.5*VFOV/180*M_PI);
image_plane_width = image_plane_height * (1.0 * framebuffer_width / framebuffer_height);
vec3 d, e, u, v, w, ud, vd;
float l, r, b, t, nx, ny;
// direction d, origin e
// ONB u, v, w
// image plane edges l, r, b, t
// window size nx, ny
e = scene_camera_position;
u = right_vector, v = up_vector, w = v3_negate(forward_vector);
l = -0.5 * image_plane_width, r = 0.5 * image_plane_width;
b = 0.5 * image_plane_height, t = -0.5 * image_plane_height;
nx = framebuffer_width, ny = framebuffer_height;
// Loop over all pixels in the framebuffer
for (j = 0; j < ny; j++) {
for (i = 0; i < nx; i++) {
ud = v3_multiply(u, (l + (r - l) * ((i + 0.5) / nx)));
vd = v3_multiply(v, (b + (t - b) * ((j + 0.5) / ny)));
d = v3_add(v3_add(ud, vd), v3_negate(w));
color = ray_color(0, e, d);
put_pixel(i, j, color.x, color.y, color.z);
}
sprintf(buf, "Ray-tracing ::: %.0f%% done", 100.0*j/framebuffer_height);
glutSetWindowTitle(buf);
}
// Done!
gettimeofday(&t1, NULL);
glutSetWindowTitle("Ray-tracing ::: done");
// Output some statistics
time_taken = 1.0 * (t1.tv_sec - t0.tv_sec) + (t1.tv_usec - t0.tv_usec) / 1000000.0;
fprintf(stderr, " done in %.1f seconds\n", time_taken);
fprintf(stderr, "... %lld total rays shot, of which %d camera rays and "
"%lld shadow rays\n", num_rays_shot,
do_antialiasing ? 4*framebuffer_width*framebuffer_height :
framebuffer_width*framebuffer_height,
num_shadow_rays_shot);
fprintf(stderr, "... %lld triangles intersection tested "
"(avg %.1f tri/ray)\n",
num_triangles_tested, 1.0*num_triangles_tested/num_rays_shot);
fprintf(stderr, "... %lld bboxes intersection tested (avg %.1f bbox/ray)\n",
num_bboxes_tested, 1.0*num_bboxes_tested/num_rays_shot);
}
vector3 egyseg( vector3 a)
{
vector3 buf;
v3_normalize(a,buf);
return buf;
}