raylib/examples/resources/shaders/glsl100/distortion.fs
2016-06-27 18:32:56 +02:00

69 lines
2.4 KiB
GLSL

#version 100
precision mediump float;
// Input vertex attributes (from vertex shader)
varying vec2 fragTexCoord;
// Input uniform values
uniform sampler2D texture0;
// NOTE: Add here your custom variables
const vec2 LeftLensCenter = vec2(0.2863248, 0.5);
const vec2 RightLensCenter = vec2(0.7136753, 0.5);
const vec2 LeftScreenCenter = vec2(0.25, 0.5);
const vec2 RightScreenCenter = vec2(0.75, 0.5);
const vec2 Scale = vec2(0.25, 0.45); //vec2(0.1469278, 0.2350845);
const vec2 ScaleIn = vec2(4, 2.2222);
const vec4 HmdWarpParam = vec4(1, 0.22, 0.24, 0);
/*
// Another set of default values
ChromaAbCorrection = {1.0, 0.0, 1.0, 0}
DistortionK = {1.0, 0.22, 0.24, 0}
Scale = {0.25, 0.5*AspectRatio, 0, 0}
ScaleIn = {4.0, 2/AspectRatio, 0, 0}
Left Screen Center = {0.25, 0.5, 0, 0}
Left Lens Center = {0.287994117, 0.5, 0, 0}
Right Screen Center = {0.75, 0.5, 0, 0}
Right Lens Center = {0.712005913, 0.5, 0, 0}
*/
// Scales input texture coordinates for distortion.
vec2 HmdWarp(vec2 in01, vec2 LensCenter)
{
vec2 theta = (in01 - LensCenter)*ScaleIn; // Scales to [-1, 1]
float rSq = theta.x*theta.x + theta.y*theta.y;
vec2 rvector = theta*(HmdWarpParam.x + HmdWarpParam.y*rSq + HmdWarpParam.z*rSq*rSq + HmdWarpParam.w*rSq*rSq*rSq);
return LensCenter + Scale*rvector;
}
void main()
{
// SOURCE: http://www.mtbs3d.com/phpbb/viewtopic.php?f=140&t=17081
// The following two variables need to be set per eye
vec2 LensCenter = fragTexCoord.x < 540 ? LeftLensCenter : RightLensCenter;
vec2 ScreenCenter = fragTexCoord.x < 540 ? LeftScreenCenter : RightScreenCenter;
vec2 tc = HmdWarp(fragTexCoord, LensCenter);
if (any(bvec2(clamp(tc,ScreenCenter-vec2(0.25,0.5), ScreenCenter+vec2(0.25,0.5)) - tc))) gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
else
{
//tc.x = gl_FragCoord.x < 640 ? (2.0 * tc.x) : (2.0 * (tc.x - 0.5));
gl_FragColor = texture2D(texture0, tc);
}
/*
// Chromatic aberration is caused when a lens can't focus every color to the same focal point.
// A simple way to fake this effect, and render it as a quick full-screen post-process,
// is to apply an offset to each color channel in a fragment shader.
vec4 rValue = texture2D(texture0, fragTexCoord - rOffset);
vec4 gValue = texture2D(texture0, fragTexCoord - gOffset);
vec4 bValue = texture2D(texture0, fragTexCoord - bOffset);
finalColor = vec4(rValue.r, gValue.g, bValue.b, 1.0);
*/
}