gtk2/demos/gtk-demo/ripple.glsl
Alexander Larsson e9885f9cde gtk-demo: Make gltransitions demo a bit snazzier
This adds a bunch of snazz to the gltransitions demo. It is perhaps
a bit overloaded now, but it demos everything that we can do.

Changes:
 * The fire shader is now not a bin, it just renders an animating
   background with no textures involved.
 * The stacks don't all start on the same page.
 * The shaderbin passes the mouse coordinate to the shader.
 * The shaderbin allows specifying a "border" so that you can
   cause effects outside the bin child (something that is new to gtk4).
 * All the buttons and the stacks are now in shader-bins that runs
   a wobbly-widget effect based on the mouse position that
   wobbles outside the child allocation.
2020-09-30 11:40:37 +02:00

44 lines
1.2 KiB
GLSL

uniform float u_time;
uniform vec2 u_mouse;
uniform sampler2D u_texture1;
#define PI 3.141592654
float decay(float v, float t)
{
return v * (1.0 / (1.0 + t*t));
}
void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
{
// Temporary to loop time every 1 sec
float time = u_time;
// we normalize all the effects according to the min height/width
float size = min(resolution.x, resolution.y);
// Animate one wave over size in 0.3 sec
float wave_speed = size / 0.3;
float wave_length = size / 1.0;
float wave_height = size * 0.1;
vec2 center = u_mouse;
vec2 direction_from_center = fragCoord - center;
float distance_from_center = length(direction_from_center);
/* Normalize direction */
direction_from_center = direction_from_center / distance_from_center;
float propagation_length = time * wave_speed;
float t = (propagation_length - distance_from_center) / wave_length;
float offset_magnitude = 0;
if (t > 0.0)
offset_magnitude = decay(wave_height * sin(t * 2.0 * PI), t);
vec2 offset = direction_from_center * min(offset_magnitude, distance_from_center);
vec2 source = fragCoord - offset;
vec2 uv2 = source / resolution;
fragColor = GskTexture(u_texture1, vec2(uv2.x, 1.0-uv2.y));
}