Polar to Cartesian shader help…
Too much coffee is making me crazy, or.. well, maybe its not the
coffee. ITS MY BRAIIIINNNNNNNNNnnnnn.
I am attempting a Polar to Cartesian transform shader while fighting
off my brains attempts to kill me.
My thought is that I should be able to run cartopol shader and then a
poltocar and get basically my same output minus weird edge pixels
that the math messes up.
However, I get nothing of the sort. I am obviously missing something.
Ive looked at Wesleys poltocar code in the kaleidoscope shader
mentioned here (second result in google for polar to cartesian glsl
// polar to cartesian conversion
vec2 no = vec2(-cos(foldtheta)*radius, -sin(foldtheta)*radius);
no = no+0.5*sizea;
The following is my fragment program in GLSL.
What am I doing wrong?
// define our rectangular texture samplers
uniform sampler2DRect tex0;
// define our varying texture coordinates
varying vec2 texcoord0;
varying vec2 texdim0;
void main (void)
const float pi=3.1415926;
vec2 point = texcoord0/texdim0; //normalize coordinates
vec2 normCoord = vec2(2.0) * (point – vec2(0.5)); // center point in
float r = length(normCoord); // find hypot – seems nicer than other
float phi = atan(normCoord.y, normCoord.x)+pi;
vec2 frompol = vec2(r* cos(phi), r* sin(phi)); // this should be
correct, yet I get an incorrect output ?
vec2 outputCoord = (frompol/vec2(2.0) + vec2(0.5)) * texdim0; //
unnormalize and remap to reg rect tex coords
gl_FragColor = texture2DRect(tex0, outputCoord);
v a d e //