OpenGL ES rotate texture
- by 0xSina
I just got started with OpenGL ES... I have a fragment:
const char * sFragment = _STRINGIFY(
varying highp vec2 coordinate;
precision mediump float;
uniform vec4 maskC;
uniform float threshold;
uniform sampler2D videoframe;
uniform sampler2D videosprite;
uniform vec4 mask;
uniform vec4 maskB;
uniform int recording;
vec3 normalize(vec3 color, float meanr)
{
return color*vec3(0.75 + meanr, 1., 1. - meanr);
}
void main() {
float d;
float dB;
float dC;
float meanr;
float meanrB;
float meanrC;
float minD;
vec4 pixelColor;
vec4 spriteColor;
pixelColor = texture2D(videoframe, coordinate);
spriteColor = texture2D(videosprite, coordinate);
meanr = (pixelColor.r + mask.r)/8.;
meanrB = (pixelColor.r + maskB.r)/8.;
meanrC = (pixelColor.r + maskC.r)/8.;
d = distance(normalize(pixelColor.rgb, meanr), normalize(mask.rgb, meanr));
dB = distance(normalize(pixelColor.rgb, meanrB), normalize(maskB.rgb, meanrB));
dC = distance(normalize(pixelColor.rgb, meanrC), normalize(maskC.rgb, meanrC));
minD = min(d, dB);
minD = min(minD, dC);
gl_FragColor = spriteColor;
if (minD > threshold) {
gl_FragColor = pixelColor;
}
}
Now, depending on wether recording is 0 or 1, I want to rotate uniform sampler2D videosprite 180 degrees (reflection in x-axis, flip vertically). How can I do that?
I found the function glRotatef(), but how do i specify that I want to rotate video sprite and not videoframe?
Thanks
