/*
* Fragment shader for axis and arrows.
*/
static void fragment_shader_axis(int y, int x, struct fragment_input *input, struct uniform_variables *vars){
if(input->frag_coord[VAR_Z] >= read_depth(y, x)){
return;
}
write_color(y, x, input->attributes[0], input->attributes[1], input->attributes[2], 1.0f);
write_depth(y, x, input->frag_coord[VAR_Z]);
}
/*
* Fragment shader for surface color based on surface normals.
*/
static void fragment_shader_color(int y, int x, struct fragment_input *input, struct uniform_variables *vars){
if(input->frag_coord[VAR_Z] >= read_depth(y, x)){
return;
}
vec3 object_normal;
object_normal[VAR_X] = input->attributes[0] / input->frag_coord[VAR_W];
object_normal[VAR_Y] = input->attributes[1] / input->frag_coord[VAR_W];
object_normal[VAR_Z] = input->attributes[2] / input->frag_coord[VAR_W];
normalize_vec3(object_normal);
if(input->front_facing == ER_FALSE){
object_normal[VAR_X] = -object_normal[VAR_X];
object_normal[VAR_Y] = -object_normal[VAR_Y];
object_normal[VAR_Z] = -object_normal[VAR_Z];
}
float red, green, blue;
red = (object_normal[VAR_X] * 0.5f + 0.5f);
red = clamp(red, 0.0f, 1.0f);
green = (object_normal[VAR_Y] * 0.5f + 0.5f);
green = clamp(green, 0.0f, 1.0f);
blue = (object_normal[VAR_X] * 0.5f + 0.5f);
blue = clamp(blue, 0.0f, 1.0f);
write_color(y, x, red, green, blue, 1.0f);
write_depth(y, x, input->frag_coord[VAR_Z]);
}
/*
* Fragment shader for surface lighting. One directional light source, phong shading.
*/
static void fragment_shader_light(int y, int x, struct fragment_input *input, struct uniform_variables *vars){
if(input->frag_coord[VAR_Z] >= read_depth(y, x)){
return;
}
float *light_dir = &(vars->uniform_float[0]);
vec3 eye_normal, object_normal;
object_normal[VAR_X] = input->attributes[0] / input->frag_coord[VAR_W];
object_normal[VAR_Y] = input->attributes[1] / input->frag_coord[VAR_W];
object_normal[VAR_Z] = input->attributes[2] / input->frag_coord[VAR_W];
eye_normal[VAR_X] = input->attributes[3] / input->frag_coord[VAR_W];
eye_normal[VAR_Y] = input->attributes[4] / input->frag_coord[VAR_W];
eye_normal[VAR_Z] = input->attributes[5] / input->frag_coord[VAR_W];
normalize_vec3(eye_normal);
normalize_vec3(object_normal);
if(input->front_facing == ER_FALSE){
eye_normal[VAR_X] = -eye_normal[VAR_X];
eye_normal[VAR_Y] = -eye_normal[VAR_Y];
eye_normal[VAR_Z] = -eye_normal[VAR_Z];
object_normal[VAR_X] = -object_normal[VAR_X];
object_normal[VAR_Y] = -object_normal[VAR_Y];
object_normal[VAR_Z] = -object_normal[VAR_Z];
}
float diffuse_term = max(0.0f, dot_vec3(light_dir, eye_normal) );
float specular_term = 0.0f;
vec3 view_vector;
vec3 half_vector;
view_vector[VAR_X] = 0.0f;
view_vector[VAR_Y] = 0.0f;
view_vector[VAR_Z] = 1.0f;
if(diffuse_term > 0.0f){
half_vector[VAR_X] = light_dir[VAR_X] + view_vector[VAR_X];
half_vector[VAR_Y] = light_dir[VAR_Y] + view_vector[VAR_Y];
half_vector[VAR_Z] = light_dir[VAR_Z] + view_vector[VAR_Z];
normalize_vec3(half_vector);
specular_term = pow( max(0.0f, dot_vec3(half_vector, eye_normal)), 50.0f );
}
float red, green, blue, light_intensity;
light_intensity = 0.6f * diffuse_term + 0.4f * specular_term;
red = (object_normal[VAR_X] * 0.5f + 0.5f) * light_intensity;
red = clamp(red, 0.0f, 1.0f);
green = (object_normal[VAR_Y] * 0.5f + 0.5f) * light_intensity;
green = clamp(green, 0.0f, 1.0f);
blue = (object_normal[VAR_Z] * 0.5f + 0.5f) * light_intensity;
blue = clamp(blue, 0.0f, 1.0f);
write_color(y, x, red, green, blue, 1.0f);
write_depth(y, x, input->frag_coord[VAR_Z]);
}
/*
* Fragment shader for texture mapped cube.
*/
static void fs_cube(int y, int x, struct fragment_input *input, struct uniform_variables *vars){
if(input->frag_coord[VAR_Z] >= read_depth(y, x)){
return;
}
struct texture* tex = vars->uniform_texture[0];
vec2 tex_coord;
vec4 tex_color;
tex_coord[VAR_S] = input->attributes[0] / input->frag_coord[VAR_W];
tex_coord[VAR_T] = input->attributes[1] / input->frag_coord[VAR_W];
texture_lod(tex, tex_coord, 0.0f, tex_color);
write_color(y, x, tex_color[0], tex_color[1], tex_color[2], 1.0f);
write_depth(y, x, input->frag_coord[VAR_Z]);
}
struct tree_node *
write_var(FILE *out, struct tree_node *t, struct lacy_env *env)
{
if (0 == strcmp(t->buffer.s, "root")) {
write_depth(out, env);
}
else if (0 == strcmp(t->buffer.s, "this")) {
struct page *p = env_get_page_top(env);
if (NULL != p) {
if (t->next != NULL && MEMBER == t->next->token) {
t = t->next->next;
t = write_member(out, t, p, env);
}
else {
fprintf(out, "%s", p->file_path);
}
}
}
else {
if (env_has_next(env)) {
struct page_attr *a;
a = env_attr_lookup(env, t->buffer.s);
if (t->next != NULL && MEMBER == t->next->token) {
t = t->next->next;
if (NULL != a) {
struct page *p = page_find(a->value.s);
t = write_member(out, t, p, env);
}
}
else
{
if (NULL != a) {
fprintf(out, "%s", a->value.s);
}
}
}
}
return t;
}
/*
* Fragment shader for texture mapped cube. Calculation of perspective correct derivatives for trilinear filtering.
*/
static void fs_cube_grad(int y, int x, struct fragment_input *input, struct uniform_variables *vars){
if(input->frag_coord[VAR_Z] >= read_depth(y, x)){
return;
}
struct texture *tex = vars->uniform_texture[0];
vec2 tex_coord;
vec4 tex_color;
tex_coord[VAR_S] = input->attributes[0] / input->frag_coord[VAR_W];
tex_coord[VAR_T] = input->attributes[1] / input->frag_coord[VAR_W];
vec2 ddx, ddy;
float one_over_w2 = 1.0f / (input->frag_coord[VAR_W] * input->frag_coord[VAR_W]);
ddx[VAR_S] = (input->ddx[0] * input->frag_coord[VAR_W] - input->attributes[0] * input->dw_dx) * one_over_w2;
ddx[VAR_T] = (input->ddx[1] * input->frag_coord[VAR_W] - input->attributes[1] * input->dw_dx) * one_over_w2;
ddy[VAR_S] = (input->ddy[0] * input->frag_coord[VAR_W] - input->attributes[0] * input->dw_dy) * one_over_w2;
ddy[VAR_T] = (input->ddy[1] * input->frag_coord[VAR_W] - input->attributes[1] * input->dw_dy) * one_over_w2;
texture_grad(tex, tex_coord, ddx, ddy, tex_color);
write_color(y, x, tex_color[0], tex_color[1], tex_color[2], 1.0f);
write_depth(y, x, input->frag_coord[VAR_Z]);
}