frequently used routines for shadertoy

shadertoy_lib.glsl

vec2 aspectCorrectedCoords(in vec2 fragCoord) {
	vec2 uv = fragCoord/iResolution.xy;
    vec2 xy = uv * 2.0 - 1.0;
    xy.x *= iResolution.x / iResolution.y;
	return xy;
}

float nearPlaneDist(in float verticalFovDegrees) {
	return 1.0 / tan(radians(verticalFovDegrees/2.0));
}

vec3 primRayDir(in vec2 xy, in float verticalFovDegrees) {
	return normalize(vec3(xy, nearPlaneDist(verticalFovDegrees)));
}