quakeforge/libs/video/renderer/vulkan/quakebsp.frag
Bill Currie 3132aa91a8 [vulkan] Get sky sheets working
The sky texture is loaded with black's alpha set to 0. While this does
hit both layers, the screen is cleared to black so it shouldn't be a
problem (and will allow having a skybox behind the sheets).
2021-01-23 23:58:34 +09:00

123 lines
3 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 sampler2DArray SkySheet;
layout (set = 0, binding = 5) uniform samplerCube SkyCube;
layout (push_constant) uniform PushConstants {
layout (offset = 64)
vec4 fog;
float time;
};
layout (location = 0) in vec4 tl_st;
layout (location = 1) in 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 vec4 (1, 0, 1, 1);
//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));
return vec4 (1, 0, 1, 1);
}
}
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);
if (doLight) {
c *= vec4 (texture (LightMap, l_st).xyz, 1);
}
c += texture (GlowMap, t_st);
}
frag_color = c;//fogBlend (c);
}