kwin/effects/data/lookingglass.frag

34 lines
754 B
GLSL
Raw Normal View History

uniform sampler2D sceneTex;
uniform float textureWidth;
uniform float textureHeight;
uniform float cursorX;
uniform float cursorY;
uniform float zoom;
uniform float radius;
#define PI 3.14159
// Converts pixel coordinates to texture coordinates
vec2 pix2tex(vec2 pix)
{
return vec2(pix.x / textureWidth, 1.0 - pix.y / textureHeight);
}
void main()
{
vec2 texcoord = gl_TexCoord[0].xy;
float dx = cursorX - texcoord.x;
float dy = cursorY - texcoord.y;
float dist = sqrt(dx*dx + dy*dy);
if(dist < radius)
{
float disp = sin(dist / radius * PI) * (zoom - 1.0) * 20.0;
texcoord.x += dx / dist * disp;
texcoord.y += dy / dist * disp;
}
gl_FragColor = texture2D(sceneTex, pix2tex(texcoord));
}