shadertory_to_quilt.glsl

 #define QAA	2                                     

const float	sideAngle = radians(35.0);
const float	horizontalAngle = radians(14.0);
const float	cameraSize = 2.0;
const float	aspectRatio = 0.75;
const vec3  	VROffset = vec3(0, 0, 9);
float quiltColumns	=	8.;
float quiltRows		=	6.;
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    vec4	accColor = vec4(0.);
    for( int m = 0; m < QAA; m++ )
    for( int n = 0; n < QAA; n++ )
    {
        // pixel coordinates
        vec2 o = (vec2(float(m), float(n)) / float(QAA) - 0.5) / iResolution.xy                                                                                 ;
		
		vec2	coord = (fragCoord / iResolution.xy  + o) * vec2(quiltColumns,quiltRows);
		vec2	fract = fract(coord);
		vec2	floor = floor(coord);
		float	imageId = floor.x + floor.y * quiltColumns;
		float	valueId = imageId / (quiltColumns * quiltRows - 1.);
		float	dist = (cameraSize / 2.) / tan(horizontalAngle / 2.);
		float	minCam = -(cameraSize / 2.) - tan(sideAngle / 2.) * dist;
		
		vec3	camPos = mix(vec3(minCam,0,dist),vec3(-minCam,0,dist),valueId);
		vec3	screenPos = vec3((fract.x-0.5)*cameraSize,(fract.y-0.5)*cameraSize/aspectRatio,0);
		
		vec3	dir = normalize(screenPos - camPos);
		vec4	color;
		mainVR(color, fragCoord, camPos - VROffset, dir);
		accColor += clamp(color, 0.0, 1.0);
	}
	fragColor = accColor / float(QAA*QAA);
}