| |
| /* |
| ** Copyright (c) 2012 The Khronos Group Inc. |
| ** |
| ** Permission is hereby granted, free of charge, to any person obtaining a |
| ** copy of this software and/or associated documentation files (the |
| ** "Materials"), to deal in the Materials without restriction, including |
| ** without limitation the rights to use, copy, modify, merge, publish, |
| ** distribute, sublicense, and/or sell copies of the Materials, and to |
| ** permit persons to whom the Materials are furnished to do so, subject to |
| ** the following conditions: |
| ** |
| ** The above copyright notice and this permission notice shall be included |
| ** in all copies or substantial portions of the Materials. |
| ** |
| ** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| ** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| ** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| ** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| ** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| ** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| ** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS. |
| */ |
| |
| |
| #ifdef GL_ES |
| precision mediump float; |
| #endif |
| uniform float GrainSize; |
| uniform vec3 DarkColor; |
| uniform vec3 colorSpread; |
| |
| varying float lightIntensity; |
| varying vec3 Position; |
| |
| void main (void) |
| { |
| // |
| // cheap noise |
| // |
| vec3 location = Position; |
| |
| vec3 floorvec = vec3(floor(Position.x * 10.0), 0.0, floor(Position.z * 10.0)); |
| vec3 noise = Position * 10.0 - floorvec - 0.5; |
| noise *= noise; |
| location += noise * 0.12; |
| |
| // |
| // distance from axis |
| // |
| float dist = location.x * location.x + location.z * location.z; |
| float grain = dist / GrainSize; |
| |
| // |
| // grain effects as function of distance |
| // |
| float brightness = fract(grain); |
| if (brightness > 0.5) |
| brightness = (1.0 - brightness); |
| vec3 color = DarkColor + 0.5 * brightness * (colorSpread); |
| |
| brightness = fract(grain*7.0); |
| if (brightness > 0.5) |
| brightness = 1.0 - brightness; |
| color -= 0.5 * brightness * colorSpread; |
| |
| // |
| // also as a function of lines parallel to the axis |
| // |
| brightness = fract(grain*47.0); |
| float line = fract(Position.z + Position.x); |
| float snap = floor(line * 30.0) * (1.0/30.0); |
| if (line < snap + 0.004) |
| color -= 0.5 * brightness * colorSpread; |
| |
| // |
| // apply lighting effects from vertex processor |
| // |
| color *= lightIntensity; |
| color = clamp(color, 0.0, 1.0); |
| |
| gl_FragColor = vec4(color, 0.1) |
| } |