quakeforge/libs/video/renderer/vulkan/shader/bsp_sky.frag
Bill Currie 00cade072c [vulkan] Implement order implement transparency
It's a bit flaky for particles, especially at higher frame rates, but
that's due to supporting only 64 overlapping pixels. A reasonable
solution is probably switching to a priority heap for the "sort" and
upping the limit.
2022-12-01 03:00:47 +09:00

103 lines
2.4 KiB
GLSL

#version 450
#extension GL_GOOGLE_include_directive : enable
#include "oit_store.finc"
layout (constant_id = 0) const bool doSkyBox = false;
layout (constant_id = 1) const bool doSkySheet = false;
layout (set = 3, binding = 0) uniform sampler2DArray SkySheet;
layout (set = 4, binding = 0) uniform samplerCube SkyBox;
layout (push_constant) uniform PushConstants {
vec4 fog;
float time;
float alpha;
float turb_scale;
};
layout (location = 0) in vec4 tl_st;
layout (location = 1) in vec3 direction;
layout (location = 2) in vec4 color;
layout(early_fragment_tests) in;
//layout (location = 0) out vec4 frag_color;
const float SCALE = 189.0 / 64.0;
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_box (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
dir = normalize(dir);
//return vec4(dir.xyz, 1) * 0.5 + vec4(0.5);
return texture (SkyBox, dir.xzy);
}
vec4
sky_color (vec3 dir, float time)
{
if (!doSkySheet) {
return sky_box (dir, time);
} if (!doSkyBox) {
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_box (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;
if (doSkyBox || doSkySheet) {
c = sky_color (direction, time);
} else {
c = vec4 (0, 0, 0, 1);
}
//frag_color = c;//fogBlend (c);
StoreFrag (c, gl_FragCoord.z);
}