civ14/Resources/Textures/Shaders/world_gradient_circle.swsl

// Has 2 circles, an inner one that is unaffected and an outer one.
light_mode unshaded;

const highp vec4 color = vec4(1.0, 1.0, 1.0, 1.0);

// Position of the center in pixel terms.
uniform highp vec2 position;
uniform highp float maxRange;
uniform highp float minRange;
uniform highp float bufferRange;
uniform highp float gradient;

void fragment() {
	highp float distance = length(FRAGCOORD.xy - position);

	if (distance > maxRange) {
		discard;
	}
	else if (distance < minRange) {
		COLOR = color;
	}
	else {
		
        	highp float ratio = 1.0 - pow((distance - minRange) / bufferRange, gradient);
		COLOR = vec4(color.x, color.y, color.z, ratio);
	}
}