mirror of
https://github.com/space-wizards/RobustToolbox.git
synced 2026-09-16 07:12:27 +02:00
20kdcandGitHub
79deaca409
Someone please performance-test this, but I think the fragment shader code simplifications speak for themselves. Radrark found the "line in polar coordinates" equation I needed and a diagram that explained the variables. That equation was essentially the missing piece to the whole thing.
26 lines
917 B
GLSL
26 lines
917 B
GLSL
|
|
// x: Angle being queried, y: Angle of closest point of line (is of 90-degree angle to line angle), z: Distance at y
|
|
varying highp vec3 fragControl;
|
|
|
|
void main()
|
|
{
|
|
// Thanks to Radrark for finding this for me. There's also a useful diagram, but this is text, so:
|
|
// r = p / cos(theta - phi)
|
|
// r: Distance to line *given angle theta*
|
|
// p: Distance to closest point of line
|
|
// theta: Angle being queried
|
|
// phi: Angle of closest point of line - inherently on 90-degree angle to line angle
|
|
highp float dist = abs(fragControl.z / cos(fragControl.x - fragControl.y));
|
|
|
|
// Main body.
|
|
#ifdef HAS_DFDX
|
|
highp float dx = dFdx(dist);
|
|
highp float dy = dFdy(dist); // I'm aware derivative of y makes no sense here but oh well.
|
|
#else
|
|
highp float dx = 1.0;
|
|
highp float dy = 1.0;
|
|
#endif
|
|
gl_FragColor = zClydeShadowDepthPack(vec2(dist, dist * dist + 0.25 * (dx*dx + dy*dy)));
|
|
}
|
|
|