#version 100 precision mediump float; uniform float u_ScreenHeight; varying vec4 v_Color; varying vec4 v_BorderColor; varying vec2 v_Pos; varying vec2 v_Scale; varying float v_BorderRadius; varying float v_BorderWidth; float _distance(in vec2 frag_coord, in vec2 position, in vec2 size, float radius) { // TODO: Try SDF approach: https://www.shadertoy.com/view/wd3XRN vec2 inner_size = size - vec2(radius, radius) * 2.0; vec2 top_left = position + vec2(radius, radius); vec2 bottom_right = top_left + inner_size; vec2 top_left_distance = top_left - frag_coord; vec2 bottom_right_distance = frag_coord - bottom_right; vec2 distance = vec2( max(max(top_left_distance.x, bottom_right_distance.x), 0.0), max(max(top_left_distance.y, bottom_right_distance.y), 0.0) ); return sqrt(distance.x * distance.x + distance.y * distance.y); } void main() { vec2 fragCoord = vec2(gl_FragCoord.x, u_ScreenHeight - gl_FragCoord.y); float internal_border = max(v_BorderRadius - v_BorderWidth, 0.0); float internal_distance = _distance( fragCoord, v_Pos + vec2(v_BorderWidth), v_Scale - vec2(v_BorderWidth * 2.0), internal_border ); float border_mix = smoothstep( max(internal_border - 0.5, 0.0), internal_border + 0.5, internal_distance ); vec4 mixed_color = mix(v_Color, v_BorderColor, border_mix); float d = _distance( fragCoord, v_Pos, v_Scale, v_BorderRadius ); float radius_alpha = 1.0 - smoothstep(max(v_BorderRadius - 0.5, 0.0), v_BorderRadius + 0.5, d); gl_FragColor = vec4(mixed_color.xyz, mixed_color.w * radius_alpha); }