replace simple snow with fancy snow code with different parameters

This commit is contained in:
Brad Parker 2016-12-11 12:59:32 -05:00
parent acbf2546d9
commit 7c176c3d14

View File

@ -1,52 +1,69 @@
#include "shaders_common.h" #include "shaders_common.h"
static const char *stock_fragment_xmb_simple_snow = GLSL( static const char *stock_fragment_xmb_simple_snow = GLSL(
uniform float time; uniform float time;
vec2 res = vec2(1920*3, 1080*3); uniform vec2 OutputSize;
float quality = 8.0;
float Cellular2D(vec2 P) { float baseScale = 1.25; // [1.0 .. 10.0]
vec2 Pi = floor(P); float density = 0.5; // [0.01 .. 1.0]
vec2 Pf = P - Pi; float speed = 0.15; // [0.1 .. 1.0]
vec2 Pt = vec2( Pi.x, Pi.y + 1.0 );
Pt = Pt - floor(Pt * ( 1.0 / 71.0 )) * 71.0;
Pt += vec2( 26.0, 161.0 );
Pt *= Pt;
Pt = Pt.xy * Pt.yx;
float hash_x = fract( Pt.x * ( 1.0 / 951.135664 ) ) * 2.0 - 1.0;
float hash_y = fract( Pt.y * ( 1.0 / 642.949883 ) ) * 2.0 - 1.0;
const float JITTER_WINDOW = 0.25;
hash_x = ( ( hash_x * hash_x * hash_x ) - sign( hash_x ) ) * JITTER_WINDOW;
hash_y = ( ( hash_y * hash_y * hash_y ) - sign( hash_y ) ) * JITTER_WINDOW;
vec2 dd = vec2(Pf.x - hash_x, Pf.y - hash_y);
float d = dd.x * dd.x + dd.y * dd.y;
return d * ( 1.0 / 1.125 );
}
float snow(vec2 pos, float time, float scale) { float rand(vec2 co)
pos.x += cos(pos.y*4.0 + time*3.14159*2.0 + 1.0/scale)/(8.0/scale); {
pos += time*scale*vec2(-0.5, 1.0); return fract(sin(dot(co.xy, vec2(12.9898, 78.233))) * 43758.5453);
return max( }
1.0 - Cellular2D(mod(pos/scale, scale*quality)*16.0)*1024.0,
0.0
) * (scale*0.5 + 0.5);
}
void main( void ) { float dist_func(vec2 distv)
float winscale = max(res.x, res.y); {
float tim = mod(time/8.0, 84.0*quality); float dist = sqrt((distv.x * distv.x) + (distv.y * distv.y)) * (40.0 / baseScale);
vec2 pos = gl_FragCoord.xy/winscale; dist = clamp(dist, 0.0, 1.0);
float a = 0.0; return cos(dist * (3.14159265358 * 0.5)) * 0.5;
a += snow(pos, tim, 1.0); }
a += snow(pos, tim, 0.7);
a += snow(pos, tim, 0.6); float random_dots(vec2 co)
a += snow(pos, tim, 0.5); {
a += snow(pos, tim, 0.4); float part = 1.0 / 20.0;
a += snow(pos, tim, 0.3); vec2 cd = floor(co / part);
a += snow(pos, tim, 0.25); float p = rand(cd);
a += snow(pos, tim, 0.125);
a = a * min(pos.y*4.0, 1.0); if (p > 0.005 * (density * 40.0))
gl_FragColor = vec4(1.0, 1.0, 1.0, a); return 0.0;
}
vec2 dpos = (vec2(fract(p * 2.0) , p) + vec2(2.0, 2.0)) * 0.25;
vec2 cellpos = fract(co / part);
vec2 distv = (cellpos - dpos);
return dist_func(distv);
}
float snow(vec2 pos, float time, float scale)
{
// add wobble
pos.x += cos(pos.y * 1.2 + time * 3.14159 * 2.0 + 1.0 / scale) / (8.0 / scale) * 4.0;
// add gravity
pos += time * scale * vec2(-0.5, 1.0) * 4.0;
return random_dots(pos / scale) * (scale * 0.5 + 0.5);
}
void main(void)
{
float tim = time * 0.4 * speed;
vec2 pos = gl_FragCoord.xy / OutputSize.xx;
float a = 0.0;
// Each of these is a layer of snow
// Remove some for better performance
// Changing the scale (3rd value) will mess with the looping
a += snow(pos, tim, 1.0);
a += snow(pos, tim, 0.7);
a += snow(pos, tim, 0.6);
a += snow(pos, tim, 0.5);
a += snow(pos, tim, 0.4);
a += snow(pos, tim, 0.3);
a += snow(pos, tim, 0.25);
a += snow(pos, tim, 0.125);
a = a * min(pos.y * 4.0, 1.0);
gl_FragColor = vec4(1.0, 1.0, 1.0, a);
}
); );