hug0hq · November 17, 2022 16:55 · Nov 4, 2014 · Oct 31, 2014 · Oct 18, 2014 · Jul 29, 2014
diff --git a/GLSL-Math.md b/GLSL-Math.md
@@ -54,8 +54,8 @@ mat4 RotateY(float theta){
 
 mat4 RotateZ(float psi){
     return mat4(
-        vec4(cos(psi),sin(psi),0.,0),
-        vec4(-sin(psi),cos(psi),0.,0.),
+        vec4(cos(psi),-sin(psi),0.,0),
+        vec4(sin(psi),cos(psi),0.,0.),
         vec4(0.,0.,1.,0.),
         vec4(0.,0.,0.,1.));
 }

diff --git a/GLSL-Math.md b/GLSL-Math.md
@@ -18,6 +18,24 @@ float cosd(float a){return cos(a * PI180);}
 From <http://duriansoftware.com/joe/An-intro-to-modern-OpenGL.-Chapter-3:-3D-transformation-and-projection.html>
 
 ```
+mat4 scale(float x, float y, float z){
+    return mat4(
+        vec4(x,   0.0, 0.0, 0.0),
+        vec4(0.0, y,   0.0, 0.0),
+        vec4(0.0, 0.0, z,   0.0),
+        vec4(0.0, 0.0, 0.0, 1.0)
+    );
+}
+
+mat4 translate(float x, float y, float z){
+    return mat4(
+        vec4(1.0, 0.0, 0.0, 0.0),
+        vec4(0.0, 1.0, 0.0, 0.0),
+        vec4(0.0, 0.0, 1.0, 0.0),
+        vec4(x,   y,   z,   1.0)
+    );
+}
+
 mat4 RotateX(float phi){
     return mat4(
         vec4(1.,0.,0.,0),

diff --git a/Math.md → GLSL-Math.md b/Math.md → GLSL-Math.md
diff --git a/Math.md b/Math.md
@@ -15,6 +15,8 @@ float cosd(float a){return cos(a * PI180);}
 
 ```
 
+From <http://duriansoftware.com/joe/An-intro-to-modern-OpenGL.-Chapter-3:-3D-transformation-and-projection.html>
+
 ```
 mat4 RotateX(float phi){
     return mat4(

diff --git a/Math.md b/Math.md
@@ -15,6 +15,32 @@ float cosd(float a){return cos(a * PI180);}
 
 ```
 
+```
+mat4 RotateX(float phi){
+    return mat4(
+        vec4(1.,0.,0.,0),
+        vec4(0.,cos(phi),-sin(phi),0.),
+        vec4(0.,sin(phi),cos(phi),0.),
+        vec4(0.,0.,0.,1.));
+}
+
+mat4 RotateY(float theta){
+    return mat4(
+        vec4(cos(theta),0.,-sin(theta),0),
+        vec4(0.,1.,0.,0.),
+        vec4(sin(theta),0.,cos(theta),0.),
+        vec4(0.,0.,0.,1.));
+}
+
+mat4 RotateZ(float psi){
+    return mat4(
+        vec4(cos(psi),sin(psi),0.,0),
+        vec4(-sin(psi),cos(psi),0.,0.),
+        vec4(0.,0.,1.,0.),
+        vec4(0.,0.,0.,1.));
+}
+```
+
 ### [IQ Functions](http://iquilezles.org/www/articles/functions/functions.htm) by Iñigo Quilez
 
 ```

diff --git a/Math.md b/Math.md
@@ -5,6 +5,7 @@ const float PI = 3.1415926535897932384626433832795;
 const float PI_2 = 1.57079632679489661923;
 const float PI_4 = 0.785398163397448309616;
 
+float PHI = (1.0+sqrtf(5.0))/2.0;
 ```
 
 ```

diff --git a/Math.md b/Math.md
@@ -1,5 +1,4 @@
-
-# Angles
+### Trigonometry
 
 ```
 const float PI = 3.1415926535897932384626433832795;
@@ -15,7 +14,7 @@ float cosd(float a){return cos(a * PI180);}
 
 ```
 
-# [IQ Functions](http://iquilezles.org/www/articles/functions/functions.htm) by Iñigo Quilez
+### [IQ Functions](http://iquilezles.org/www/articles/functions/functions.htm) by Iñigo Quilez
 
 ```
 float almostIdentity( float x, float m, float n ){

diff --git a/Math.md b/Math.md
@@ -1,14 +1,14 @@
 
-```
+# Angles
 
+```
 const float PI = 3.1415926535897932384626433832795;
 const float PI_2 = 1.57079632679489661923;
 const float PI_4 = 0.785398163397448309616;
 
 ```
 
 ```
-
 float PI180 = float(PI / 180.0);
 float sind(float a){return sin(a * PI180);}
 float cosd(float a){return cos(a * PI180);}

diff --git a/Math.md b/Math.md
@@ -14,3 +14,52 @@ float sind(float a){return sin(a * PI180);}
 float cosd(float a){return cos(a * PI180);}
 
 ```
+
+# [IQ Functions](http://iquilezles.org/www/articles/functions/functions.htm) by Iñigo Quilez
+
+```
+float almostIdentity( float x, float m, float n ){
+    if( x>m ) return x;
+
+    const float a = 2.0f*n - m
+    const float b = 2.0f*m - 3.0f*n;
+    const float t = x/m;
+
+    return (a*t + b)*t*t + n;
+}
+```
+
+```
+float impulse( float k, float x ){
+    const float h = k*x;
+    return h*expf(1.0f-h);
+}
+```
+
+```
+float cubicPulse( float c, float w, float x ){
+    x = fabsf(x - c);
+    if( x>w ) return 0.0f;
+    x /= w;
+    return 1.0f - x*x*(3.0f-2.0f*x);
+}
+```
+
+```
+float expStep( float x, float k, float n ){
+    return expf( -k*powf(x,n) );
+}
+```
+
+```	
+float parabola( float x, float k ){
+    return powf( 4.0f*x*(1.0f-x), k );
+}
+```
+
+```
+float pcurve( float x, float k ){
+    float k = powf(a+b,a+b) / (pow(a,a)*pow(b,b));
+    return k * powf( x, a ) * powf( 1.0-x, b );
+}
+```
diff --git a/Math.md b/Math.md
@@ -1,10 +1,16 @@
+
 ```
+
 const float PI = 3.1415926535897932384626433832795;
 const float PI_2 = 1.57079632679489661923;
 const float PI_4 = 0.785398163397448309616;
 
+```
+
+```
+
 float PI180 = float(PI / 180.0);
 float sind(float a){return sin(a * PI180);}
 float cosd(float a){return cos(a * PI180);}
 
-```
+```
diff --git a/Math.md b/Math.md
@@ -1,4 +1,4 @@
-˜˜˜
+```
 const float PI = 3.1415926535897932384626433832795;
 const float PI_2 = 1.57079632679489661923;
 const float PI_4 = 0.785398163397448309616;
@@ -7,4 +7,4 @@ float PI180 = float(PI / 180.0);
 float sind(float a){return sin(a * PI180);}
 float cosd(float a){return cos(a * PI180);}
 
-˜˜˜
+```
diff --git a/Math.md b/Math.md
@@ -1,5 +1,4 @@
-'''
-
+˜˜˜
 const float PI = 3.1415926535897932384626433832795;
 const float PI_2 = 1.57079632679489661923;
 const float PI_4 = 0.785398163397448309616;
@@ -8,4 +7,4 @@ float PI180 = float(PI / 180.0);
 float sind(float a){return sin(a * PI180);}
 float cosd(float a){return cos(a * PI180);}
 
-'''
+˜˜˜
diff --git a/Math.md b/Math.md
@@ -1,7 +1,11 @@
+'''
+
 const float PI = 3.1415926535897932384626433832795;
 const float PI_2 = 1.57079632679489661923;
 const float PI_4 = 0.785398163397448309616;
 
 float PI180 = float(PI / 180.0);
 float sind(float a){return sin(a * PI180);}
-float cosd(float a){return cos(a * PI180);}
+float cosd(float a){return cos(a * PI180);}
+
+'''
diff --git a/Math.md b/Math.md
@@ -1,5 +1,7 @@
-#define PI 3.1415926535897932384626433832795
-#define PI180 0.0174532925199
+const float PI = 3.1415926535897932384626433832795;
+const float PI_2 = 1.57079632679489661923;
+const float PI_4 = 0.785398163397448309616;
 
-#define sind(a) sin(float(a) * PI180)
-#define cosd(a) cos(float(a) * PI180)
+float PI180 = float(PI / 180.0);
+float sind(float a){return sin(a * PI180);}
+float cosd(float a){return cos(a * PI180);}
diff --git a/Math.md b/Math.md
@@ -0,0 +1,5 @@
+#define PI 3.1415926535897932384626433832795
+#define PI180 0.0174532925199
+
+#define sind(a) sin(float(a) * PI180)
+#define cosd(a) cos(float(a) * PI180)