38 lines
1023 B
Plaintext
38 lines
1023 B
Plaintext
light_mode unshaded;
|
|
|
|
uniform sampler2D SCREEN_TEXTURE;
|
|
uniform highp float visibility; // number between -1 and 1
|
|
uniform mediump vec2 reference;
|
|
|
|
const mediump float time_scale = 0.25;
|
|
const mediump float distance_scale = 0.125;
|
|
|
|
void fragment() {
|
|
|
|
highp vec4 sprite = zTexture(UV);
|
|
|
|
if (sprite.a == 0.0) {
|
|
discard;
|
|
}
|
|
|
|
// get distortion magnitude. hand crafted from a random jumble of trig functions
|
|
highp vec2 coords = (FRAGCOORD.xy + reference) * distance_scale;
|
|
highp float w = sin(TIME + (coords.x + coords.y + 2.0*sin(TIME*time_scale) * sin(TIME*time_scale + coords.x - coords.y)) );
|
|
|
|
// visualize distortion via:
|
|
// COLOR = vec4(w,w,w,1.0);
|
|
|
|
w *= (3.0 + visibility * 2.0);
|
|
|
|
highp vec4 background = zTextureSpec(SCREEN_TEXTURE, ( FRAGCOORD.xy + vec2(w) ) * SCREEN_PIXEL_SIZE );
|
|
|
|
lowp float alpha;
|
|
if (visibility>0.0)
|
|
alpha = sprite.a * visibility;
|
|
else
|
|
alpha = 0.0;
|
|
|
|
COLOR.xyz = mix(background.xyz, sprite.xyz, alpha);
|
|
COLOR.a = 1.0;
|
|
}
|