quakeforge/libs/video/renderer/vulkan/quakebsp.frag
Bill Currie c7b2843c0e [vulkan] Create shanders for brush models
The fragment shader is a bit of a mini mega-shader, but I do want to try
out specializations.
2021-01-18 17:13:52 +09:00

122 lines
2.9 KiB
GLSL

#version 450
layout (set = 0, binding = 1) uniform sampler2D Texture;
layout (set = 0, binding = 2) uniform sampler2D Glowmap;
layout (set = 0, binding = 3) uniform sampler2D Lightmap;
layout (set = 0, binding = 4) uniform samplerCube SkyCube;
layout (set = 0, binding = 5) uniform sampler2DArray SkySheet;
layout (push_constant) uniform PushConstants {
float time;
vec4 fog;
};
layout (location = 0) in vec4 tl_st;
layout (location = 1) in vec4 color;
layout (location = 2) out vec3 direction;
layout (location = 0) out vec4 frag_color;
layout (constant_id = 0) const bool doWarp = false;
layout (constant_id = 1) const bool doLight = true;
layout (constant_id = 2) const bool doSkyCube = false;
layout (constant_id = 3) const bool doSkySheet = false;
const float PI = 3.14159265;
const float SPEED = 20.0;
const float CYCLE = 128.0;
const float FACTOR = PI * 2.0 / CYCLE;
const vec2 BIAS = vec2 (1.0, 1.0);
const float SCALE = 8.0;
vec2
warp_st (vec2 st, float time)
{
vec2 angle = st.ts * CYCLE / 2.0;
vec2 phase = vec2 (time, time) * SPEED;
return st + (sin ((angle + phase) * FACTOR) + BIAS) / SCALE;
}
vec4
fogBlend (vec4 color)
{
float az = fog.a * gl_FragCoord.z / gl_FragCoord.w;
vec3 fog_color = fog.rgb;
float fog_factor = exp (-az * az);
return vec4 (mix (fog_color.rgb, color.rgb, fog_factor), color.a);
}
vec4
sky_sheet (vec3 dir, float time)
{
float len;
vec2 flow = vec2 (1.0, 1.0);
vec2 base;
vec3 st1, st2;
vec4 c1, c2, c;
dir.z *= 3.0;
len = dot (dir, dir);
len = SCALE * inversesqrt (len);
base = dir.yx * vec2(1.0, -1.0) * len;
st1 = vec3 (base + flow * time / 8.0, 0);
st2 = vec3 (base + flow * time / 16.0, 1);
c1 = texture (SkySheet, st1);
c2 = texture (SkySheet, st2);
c = vec4 (mix (c2.rgb, c1.rgb, c1.a), max (c1.a, c2.a));
return c;
}
vec4
sky_cube (vec3 dir, float time)
{
// NOTE: quake's world is right-handed with Z up and X forward, but
// Vulkan's cube maps are left-handed with Y up and Z forward. The
// rotation to X foward is done by the Sky matrix so all that's left
// to do here is swizzle the Y and Z coordinates
return texture (SkyCube, dir.xzy);
}
vec4
sky_color (vec3 dir, float time)
{
if (!doSkySheet) {
return sky_cube (dir, time);
} if (!doSkyCube) {
return sky_sheet (dir, time);
} else {
// can see through the sheet (may look funny when looking down)
// maybe have 4 sheet layers instead of 2?
vec4 c1 = sky_sheet (dir, time);
vec4 c2 = sky_cube (dir, time);
return vec4 (mix (c2.rgb, c1.rgb, c1.a), max (c1.a, c2.a));
}
}
void
main (void)
{
vec4 c;
vec2 t_st = tl_st.xy;
vec2 l_st = tl_st.zw;
if (doWarp) {
t_st = warp_st (t_st, time);
}
if (doSkyCube || doSkySheet) {
c = sky_color (direction, time);
} else {
c = texture (Texture, t_st) * color;
}
if (doLight) {
c *= texture (Lightmap, l_st);
}
c += texture (Glowmap, t_st);
frag_color = fogBlend (c);
}