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|
extern crate nalgebra;
mod sdl;
pub mod win;
pub mod sdf;
use nalgebra::{Vector3, Matrix3, Rotation3};
type Vec3 = Vector3<f32>;
type Mat3 = Matrix3<f32>;
type Rot3 = Rotation3<f32>;
struct View {
pos: Vec3,
yaw: f32,
pitch: f32
}
impl Default for View {
fn default() -> Self {
Self {
pos: Vec3::zeros(),
yaw: 0.0,
pitch: 0.0
}
}
}
impl View {
/// `camera_rotation() * vec3(0, 0, -1)` is the direction the camera is pointing
fn camera_rotation(&self) -> Mat3 {
*Rot3::from_euler_angles(self.pitch, self.yaw, 0.0).matrix()
}
}
fn try_main() -> Result<(), String> {
let my_sdf = sdf::Sdf::sphere();
let mut window = win::Window::new("AutoSDF", 1280, 720, true)
.map_err(|e| format!("Error creating window: {e}"))?;
let mut fshader_source = String::new();
fshader_source.push_str("
IN vec2 pos;
uniform vec3 u_camera_position;
uniform mat3 u_camera_rotation;
");
my_sdf.to_glsl(&mut fshader_source);
fshader_source.push_str("
#define ITERATIONS 30
#define AA_X 2
#define AA_Y 2
float fbm(vec3 p) {
float t = 0.0;
float freq = 24.0;
mat3 m = mat3(cos(1.),sin(1.),0,
-sin(1.),cos(1.),0,
0, 0, 1) * mat3(
1, 0, 0,
0, cos(1.),sin(1.),
0, -sin(1.),cos(1.)
);
for(int i = 0; i < 5; i++)
{
p = m * p;
t += pow(0.6, float(i)) * sin(freq*p.x)*sin(freq*p.y)*sin(freq*p.z);
freq *= 2.0;
}
return t;
}
vec3 normal(vec3 p)
{
// thanks to https://iquilezles.org/articles/normalsSDF/
float h = 0.0001;
vec2 k = vec2(1.,-1.);
vec3 sdf_normal = k.xyy*sdf(p + k.xyy*h) +
k.yyx*sdf(p + k.yyx*h) +
k.yxy*sdf(p + k.yxy*h) +
k.xxx*sdf(p + k.xxx*h);
vec3 noise_normal = k.xyy*fbm(p + k.xyy*h) +
k.yyx*fbm(p + k.yyx*h) +
k.yxy*fbm(p + k.yxy*h) +
k.xxx*fbm(p + k.xxx*h);
return normalize(sdf_normal + 0.003 * noise_normal);
}
void main() {
float focal_length = 0.3;
float min_dist = 10.;
vec2 inv_screen_size = 1.0 / vec2(1280.0, 720.0); // @TODO
vec2 aa_delta = inv_screen_size / vec2(AA_X, AA_Y);
vec3 final_color = vec3(0);
for (int m = 0; m < AA_X; m++) {
for (int n = 0; n < AA_Y; n++) {
vec3 p = u_camera_position;
vec2 aa_offset = vec2(float(m), float(n)) * aa_delta;
vec3 delta = normalize(u_camera_rotation * vec3(pos + aa_offset, -focal_length));
int i;
for (i = 0; i < ITERATIONS; i++) {
float dist = sdf(p);
min_dist = min(min_dist, dist);
if (dist <= 0.01) {
float L = 0.3 + max(0., dot(normal(p), normalize(vec3(.8,1,.6))));
final_color += L * vec3(1.0, 0.0, 0.0);
break;
}
p += dist * delta;
}
}
}
final_color *= 1.0 / (AA_X * AA_Y);
o_color = vec4(final_color, 1.0);
}");
println!("{fshader_source}");
let program = window.create_program(
"attribute vec2 v_pos;
OUT vec2 pos;
uniform float u_aspect_ratio;
void main() {
pos = v_pos * vec2(u_aspect_ratio, 1.0);
gl_Position = vec4(v_pos, 0.0, 1.0);
}",
&fshader_source
).map_err(|e| format!("Error compiling shader:\n{e}"))?;
let mut buffer = window.create_buffer();
let data: &[[f32; 2]] = &[
[-1.0, -1.0],
[1.0, -1.0],
[1.0, 1.0],
[-1.0, -1.0],
[1.0, 1.0],
[-1.0, 1.0],
];
window.set_buffer_data(&mut buffer, data);
let mut array = window.create_vertex_array(buffer, &program);
window.array_attrib2f(&mut array, "v_pos", 0);
let mut view = View::default();
'mainloop: loop {
while let Some(event) = window.next_event() {
use win::Event::*;
match event {
Quit => break 'mainloop,
_ => {},
}
}
window.viewport_full_screen();
view.yaw += 0.002;
window.clear_screen(win::ColorF32::BLACK);
window.use_program(&program);
window.uniform1f("u_aspect_ratio", window.aspect_ratio());
window.uniform3f("u_camera_position", view.pos.x, view.pos.y, view.pos.z);
window.uniform3x3f("u_camera_rotation", view.camera_rotation().as_slice());
window.draw_array(&array);
window.swap();
}
Ok(())
}
fn main() {
if let Err(e) = try_main() {
win::display_error_message(&e);
}
}
|
