fteqw/engine/shaders/glsl/fxaa.glsl
2015-07-14 15:02:06 +00:00

64 lines
2 KiB
GLSL

//
//This shader implements super-sampled anti-aliasing.
//
varying vec2 texcoord;
#ifdef VERTEX_SHADER
attribute vec2 v_texcoord;
void main()
{
texcoord = v_texcoord.xy;
texcoord.y = 1.0 - texcoord.y;
gl_Position = ftetransform();
}
#endif
#ifdef FRAGMENT_SHADER
uniform sampler2D s_t0;
uniform vec2 e_sourcesize;
void main( void )
{
float FXAA_SPAN_MAX = 8.0;
float FXAA_REDUCE_MUL = 1.0/8.0;
float FXAA_REDUCE_MIN = 1.0/128.0;
vec3 rgbNW=texture2D(s_t0,texcoord+(vec2(-1.0,-1.0)/e_sourcesize)).xyz;
vec3 rgbNE=texture2D(s_t0,texcoord+(vec2(1.0,-1.0)/e_sourcesize)).xyz;
vec3 rgbSW=texture2D(s_t0,texcoord+(vec2(-1.0,1.0)/e_sourcesize)).xyz;
vec3 rgbSE=texture2D(s_t0,texcoord+(vec2(1.0,1.0)/e_sourcesize)).xyz;
vec3 rgbM=texture2D(s_t0,texcoord).xyz;
vec3 luma=vec3(0.299, 0.587, 0.114);
float lumaNW = dot(rgbNW, luma);
float lumaNE = dot(rgbNE, luma);
float lumaSW = dot(rgbSW, luma);
float lumaSE = dot(rgbSE, luma);
float lumaM = dot(rgbM, luma);
float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));
vec2 dir;
dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
dir.y = ((lumaNW + lumaSW) - (lumaNE + lumaSE));
float dirReduce = max((lumaNW + lumaNE + lumaSW + lumaSE) * (0.25 * FXAA_REDUCE_MUL), FXAA_REDUCE_MIN);
float rcpDirMin = 1.0/(min(abs(dir.x), abs(dir.y)) + dirReduce);
dir = min(vec2( FXAA_SPAN_MAX, FXAA_SPAN_MAX),
max(vec2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX),
dir * rcpDirMin)) / e_sourcesize;
vec3 rgbA = (1.0/2.0) * (texture2D(s_t0, texcoord.xy + dir * (1.0/3.0 - 0.5)).xyz + texture2D(s_t0, texcoord.xy + dir * (2.0/3.0 - 0.5)).xyz);
vec3 rgbB = rgbA * (1.0/2.0) + (1.0/4.0) * (texture2D(s_t0, texcoord.xy + dir * (0.0/3.0 - 0.5)).xyz + texture2D(s_t0, texcoord.xy + dir * (3.0/3.0 - 0.5)).xyz);
float lumaB = dot(rgbB, luma);
if((lumaB < lumaMin) || (lumaB > lumaMax))
gl_FragColor.xyz=rgbA;
else
gl_FragColor.xyz=rgbB;
gl_FragColor.a = 1.0;
}
#endif