#extension GL_EXT_gpu_shader4 : enable | |
uniform sampler2D m_Texture; | |
uniform vec2 g_Resolution; | |
uniform float m_VxOffset; | |
uniform float m_SpanMax; | |
uniform float m_ReduceMul; | |
varying vec2 texCoord; | |
varying vec4 posPos; | |
#define FxaaTex(t, p) texture2D(t, p) | |
#if __VERSION__ >= 130 | |
#define OffsetVec(a, b) ivec2(a, b) | |
#define FxaaTexOff(t, p, o, r) textureOffset(t, p, o) | |
#elif defined(GL_EXT_gpu_shader4) | |
#define OffsetVec(a, b) ivec2(a, b) | |
#define FxaaTexOff(t, p, o, r) texture2DLodOffset(t, p, 0.0, o) | |
#else | |
#define OffsetVec(a, b) vec2(a, b) | |
#define FxaaTexOff(t, p, o, r) texture2D(t, p + o * r) | |
#endif | |
vec3 FxaaPixelShader( | |
vec4 posPos, // Output of FxaaVertexShader interpolated across screen. | |
sampler2D tex, // Input texture. | |
vec2 rcpFrame) // Constant {1.0/frameWidth, 1.0/frameHeight}. | |
{ | |
#define FXAA_REDUCE_MIN (1.0/128.0) | |
//#define FXAA_REDUCE_MUL (1.0/8.0) | |
//#define FXAA_SPAN_MAX 8.0 | |
vec3 rgbNW = FxaaTex(tex, posPos.zw).xyz; | |
vec3 rgbNE = FxaaTexOff(tex, posPos.zw, OffsetVec(1,0), rcpFrame.xy).xyz; | |
vec3 rgbSW = FxaaTexOff(tex, posPos.zw, OffsetVec(0,1), rcpFrame.xy).xyz; | |
vec3 rgbSE = FxaaTexOff(tex, posPos.zw, OffsetVec(1,1), rcpFrame.xy).xyz; | |
vec3 rgbM = FxaaTex(tex, posPos.xy).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 * m_ReduceMul), | |
FXAA_REDUCE_MIN); | |
float rcpDirMin = 1.0/(min(abs(dir.x), abs(dir.y)) + dirReduce); | |
dir = min(vec2( m_SpanMax, m_SpanMax), | |
max(vec2(-m_SpanMax, -m_SpanMax), | |
dir * rcpDirMin)) * rcpFrame.xy; | |
vec3 rgbA = (1.0/2.0) * ( | |
FxaaTex(tex, posPos.xy + dir * vec2(1.0/3.0 - 0.5)).xyz + | |
FxaaTex(tex, posPos.xy + dir * vec2(2.0/3.0 - 0.5)).xyz); | |
vec3 rgbB = rgbA * (1.0/2.0) + (1.0/4.0) * ( | |
FxaaTex(tex, posPos.xy + dir * vec2(0.0/3.0 - 0.5)).xyz + | |
FxaaTex(tex, posPos.xy + dir * vec2(3.0/3.0 - 0.5)).xyz); | |
float lumaB = dot(rgbB, luma); | |
if ((lumaB < lumaMin) || (lumaB > lumaMax)) | |
{ | |
return rgbA; | |
} | |
else | |
{ | |
return rgbB; | |
} | |
} | |
void main() | |
{ | |
vec2 rcpFrame = vec2(1.0) / g_Resolution; | |
gl_FragColor = vec4(FxaaPixelShader(posPos, m_Texture, rcpFrame), 1.0); | |
} |