In this example with shadertoy online tool I will show you how to map a texture from iChannel texture input and UV areas.
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
vec2 uv = fragCoord.xy / iResolution.xy;
vec4 color = vec4(0.0,0.0,0.0,0.0);
if (uv.x > 0.0 && uv.x < 0.5)
{
color = texture(iChannel0, vec2(1.0 - (uv.x/0.5), uv.y/0.5));
}
else if (uv.x > 0.5 && uv.x < 1.0)
{
color = texture(iChannel1, vec2(1.0 - (uv.x/0.5), uv.y));
}
fragColor = color;
} You can see this example online:
