slang-shaders/procedural/mudlord-poc.slang
mudlord 35227f6dff Added some proof of concept procedural graphics shaders.
These do not postprocess per se, but render entirely new graphics.
This is purely an abuse of the postprocess system. Would be ideal
with async compute, but what the hell :D
2016-07-29 13:25:23 +10:00

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#version 450
// proof of concept procedural shader
// done for RA Vulkan backend
// written by mudlord.
layout(std140, set = 0, binding = 0) uniform UBO
{
mat4 MVP;
vec4 OutputSize;
vec4 OriginalSize;
vec4 SourceSize;
uint FrameCount;
} global;
#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 vTexCoord;
const vec2 madd = vec2(0.5, 0.5);
void main()
{
gl_Position = global.MVP * Position;
vTexCoord = Position.xy;
}
#pragma stage fragment
layout(location = 0) in vec2 vTexCoord;
layout(location = 0) out vec4 FragColor;
vec3 rotatex(in vec3 p, float ang) { return vec3(p.x, p.y*cos(ang) - p.z*sin(ang), p.y*sin(ang) + p.z*cos(ang)); }
vec3 rotatey(in vec3 p, float ang) { return vec3(p.x*cos(ang) - p.z*sin(ang), p.y, p.x*sin(ang) + p.z*cos(ang)); }
vec3 rotatez(in vec3 p, float ang) { return vec3(p.x*cos(ang) - p.y*sin(ang), p.x*sin(ang) + p.y*cos(ang), p.z); }
float scene(vec3 p)
{
float time = float(global.FrameCount)*0.015;
p = rotatex(p, 0.18*time);
p = rotatez(p, 0.20*time);
p = rotatey(p, 0.22*time);
float d0 = length(max(abs(p) - 0.5, 0.0)) - 0.01 + clamp(sin((p.x +p.y + p.z)*20.0)*0.03, 0.0, 1.0);
float d1 = length(p) - 0.5;
return sin(max(d0, -d1));
}
vec3 get_normal(vec3 p)
{
vec3 eps = vec3(0.01, 0.0, 0.0);
float nx = scene(p + eps.xyy) - scene(p - eps.xyy);
float ny = scene(p + eps.yxy) - scene(p - eps.yxy);
float nz = scene(p + eps.yyx) - scene(p - eps.yyx);
return normalize(vec3(nx, ny, nz));
}
void main(void)
{
vec2 p = 2.0 * (vTexCoord.xy*global.OutputSize.xy) / global.OutputSize.xy - 1.0;
p.x *= global.OutputSize.x / global.OutputSize.y;
vec3 ro = vec3(0.0, 0.0, 1.7);
vec3 rd = normalize(vec3(p.x, p.y, -1.4));
vec3 color = (1.0 - vec3(length(p*0.5)))*0.2;
vec3 pos = ro;
float dist = 0.0;
for (int i = 0; i < 64; i++)
{
float d = scene(pos);
pos += rd*d;
dist += d;
}
if (dist < 100.0)
{
vec3 n = get_normal(pos);
vec3 r = reflect(normalize(pos - ro), n);
vec3 h = -normalize(n + pos - ro);
float diff = 1.0*clamp(dot(n, normalize(vec3(1, 1, 1))), 0.0, 1.0);
float diff2 = 0.2*clamp(dot(n, normalize(vec3(0.7, -1, 0.5))), 0.0, 1.0);
float diff3 = 0.1*clamp(dot(n, normalize(vec3(-0.7, -0.4, 0.7))), 0.0, 1.0);
float spec = pow(clamp(dot(h, normalize(vec3(1, 1, 1))), 0.0, 1.0), 50.0);
float amb = 0.2 + pos.y;
color = diff*vec3(1, 1, 1) + diff2*vec3(1, 0, 0) + diff3*vec3(1, 0, 1) + spec*vec3(1, 1, 1) + amb*vec3(0.2, 0.2, 0.2);
color /= dist;
}
FragColor = vec4(color, 1.0);
}