96 lines
2.5 KiB
GLSL
96 lines
2.5 KiB
GLSL
#define PI 3.14159265359
|
|
#define PI2 6.28318530718
|
|
#define PI_HALF 1.5707963267949
|
|
#define RECIPROCAL_PI 0.31830988618
|
|
#define RECIPROCAL_PI2 0.15915494
|
|
#define LOG2 1.442695
|
|
#define EPSILON 1e-6
|
|
|
|
#define saturate(a) clamp( a, 0.0, 1.0 )
|
|
#define whiteCompliment(a) ( 1.0 - saturate( a ) )
|
|
|
|
float pow2( const in float x ) { return x*x; }
|
|
float pow3( const in float x ) { return x*x*x; }
|
|
float pow4( const in float x ) { float x2 = x*x; return x2*x2; }
|
|
float average( const in vec3 color ) { return dot( color, vec3( 0.3333 ) ); }
|
|
// expects values in the range of [0,1]x[0,1], returns values in the [0,1] range.
|
|
// do not collapse into a single function per: http://byteblacksmith.com/improvements-to-the-canonical-one-liner-glsl-rand-for-opengl-es-2-0/
|
|
highp float rand( const in vec2 uv ) {
|
|
const highp float a = 12.9898, b = 78.233, c = 43758.5453;
|
|
highp float dt = dot( uv.xy, vec2( a,b ) ), sn = mod( dt, PI );
|
|
return fract(sin(sn) * c);
|
|
}
|
|
|
|
struct IncidentLight {
|
|
vec3 color;
|
|
vec3 direction;
|
|
bool visible;
|
|
};
|
|
|
|
struct ReflectedLight {
|
|
vec3 directDiffuse;
|
|
vec3 directSpecular;
|
|
vec3 indirectDiffuse;
|
|
vec3 indirectSpecular;
|
|
};
|
|
|
|
struct GeometricContext {
|
|
vec3 position;
|
|
vec3 normal;
|
|
vec3 viewDir;
|
|
};
|
|
|
|
vec3 transformDirection( in vec3 dir, in mat4 matrix ) {
|
|
|
|
return normalize( ( matrix * vec4( dir, 0.0 ) ).xyz );
|
|
|
|
}
|
|
|
|
// http://en.wikibooks.org/wiki/GLSL_Programming/Applying_Matrix_Transformations
|
|
vec3 inverseTransformDirection( in vec3 dir, in mat4 matrix ) {
|
|
|
|
return normalize( ( vec4( dir, 0.0 ) * matrix ).xyz );
|
|
|
|
}
|
|
|
|
vec3 projectOnPlane(in vec3 point, in vec3 pointOnPlane, in vec3 planeNormal ) {
|
|
|
|
float distance = dot( planeNormal, point - pointOnPlane );
|
|
|
|
return - distance * planeNormal + point;
|
|
|
|
}
|
|
|
|
float sideOfPlane( in vec3 point, in vec3 pointOnPlane, in vec3 planeNormal ) {
|
|
|
|
return sign( dot( point - pointOnPlane, planeNormal ) );
|
|
|
|
}
|
|
|
|
vec3 linePlaneIntersect( in vec3 pointOnLine, in vec3 lineDirection, in vec3 pointOnPlane, in vec3 planeNormal ) {
|
|
|
|
return lineDirection * ( dot( planeNormal, pointOnPlane - pointOnLine ) / dot( planeNormal, lineDirection ) ) + pointOnLine;
|
|
|
|
}
|
|
|
|
mat3 transposeMat3( const in mat3 m ) {
|
|
|
|
mat3 tmp;
|
|
|
|
tmp[ 0 ] = vec3( m[ 0 ].x, m[ 1 ].x, m[ 2 ].x );
|
|
tmp[ 1 ] = vec3( m[ 0 ].y, m[ 1 ].y, m[ 2 ].y );
|
|
tmp[ 2 ] = vec3( m[ 0 ].z, m[ 1 ].z, m[ 2 ].z );
|
|
|
|
return tmp;
|
|
|
|
}
|
|
|
|
// https://en.wikipedia.org/wiki/Relative_luminance
|
|
float linearToRelativeLuminance( const in vec3 color ) {
|
|
|
|
vec3 weights = vec3( 0.2126, 0.7152, 0.0722 );
|
|
|
|
return dot( weights, color.rgb );
|
|
|
|
}
|