Files
Terrarum/src/shaders/boxdown.frag
2022-02-11 17:59:21 +09:00

31 lines
1.0 KiB
GLSL

#version 130
#ifdef GL_ES
precision mediump float;
#endif
varying vec4 v_color;
varying vec2 v_texCoords;
uniform sampler2D u_texture;
// recommended value: n / vec2(fbo_width, fbo_height) where n is something like {0.5, 1, 2, 4, ... }
// that, or simply 0.5, depending on how your uv coord works
uniform vec2 halfpixel = vec2(0.0, 0.0);
vec2 doublex = vec2(2.0, 0.0);
vec2 doubley = vec2(0.0, 2.0);
vec2 twister = vec2(1.0, -1.0);
vec2 boolean = vec2(1.0, 0.0);
void main() {
vec4 sum = texture2D(u_texture, v_texCoords) +
texture2D(u_texture, v_texCoords + halfpixel) +
texture2D(u_texture, v_texCoords - halfpixel) +
texture2D(u_texture, v_texCoords + halfpixel * twister) +
texture2D(u_texture, v_texCoords - halfpixel * twister) +
texture2D(u_texture, v_texCoords + halfpixel * boolean.xy) +
texture2D(u_texture, v_texCoords - halfpixel * boolean.xy) +
texture2D(u_texture, v_texCoords + halfpixel * boolean.yx) +
texture2D(u_texture, v_texCoords - halfpixel * boolean.yx) ;
gl_FragColor = sum / 9.0;
}