virtualx-engine/drivers/gles3/shaders/cube_to_dp.glsl
2018-08-24 13:42:18 +02:00

75 lines
1.8 KiB
GLSL

[vertex]
layout(location = 0) in highp vec4 vertex_attrib;
layout(location = 4) in vec2 uv_in;
out vec2 uv_interp;
void main() {
uv_interp = uv_in;
gl_Position = vertex_attrib;
}
[fragment]
uniform highp samplerCube source_cube; //texunit:0
in vec2 uv_interp;
uniform bool z_flip;
uniform highp float z_far;
uniform highp float z_near;
uniform highp float bias;
void main() {
highp vec3 normal = vec3(uv_interp * 2.0 - 1.0, 0.0);
/*
if (z_flip) {
normal.z = 0.5 - 0.5 * ((normal.x * normal.x) + (normal.y * normal.y));
} else {
normal.z = -0.5 + 0.5 * ((normal.x * normal.x) + (normal.y * normal.y));
}
*/
//normal.z = sqrt(1.0 - dot(normal.xy, normal.xy));
//normal.xy *= 1.0 + normal.z;
normal.z = 0.5 - 0.5 * ((normal.x * normal.x) + (normal.y * normal.y));
normal = normalize(normal);
/*
normal.z = 0.5;
normal = normalize(normal);
*/
if (!z_flip) {
normal.z = -normal.z;
}
//normal = normalize(vec3(uv_interp * 2.0 - 1.0, 1.0));
float depth = texture(source_cube, normal).r;
// absolute values for direction cosines, bigger value equals closer to basis axis
vec3 unorm = abs(normal);
if ((unorm.x >= unorm.y) && (unorm.x >= unorm.z)) {
// x code
unorm = normal.x > 0.0 ? vec3(1.0, 0.0, 0.0) : vec3(-1.0, 0.0, 0.0);
} else if ((unorm.y > unorm.x) && (unorm.y >= unorm.z)) {
// y code
unorm = normal.y > 0.0 ? vec3(0.0, 1.0, 0.0) : vec3(0.0, -1.0, 0.0);
} else if ((unorm.z > unorm.x) && (unorm.z > unorm.y)) {
// z code
unorm = normal.z > 0.0 ? vec3(0.0, 0.0, 1.0) : vec3(0.0, 0.0, -1.0);
} else {
// oh-no we messed up code
// has to be
unorm = vec3(1.0, 0.0, 0.0);
}
float depth_fix = 1.0 / dot(normal, unorm);
depth = 2.0 * depth - 1.0;
float linear_depth = 2.0 * z_near * z_far / (z_far + z_near - depth * (z_far - z_near));
gl_FragDepth = (linear_depth * depth_fix + bias) / z_far;
}