OpenGL動感模糊

glsl動感模糊效果，模擬運動時產生上一幀的殘留，簡單的對每一個像素進行相加，最後再均值一下。可使用shadertoy直接運行：

#iChannel1"file://./car.png"

#define PI 3.14159265359
void mainImage(out vec4 fragColor,in vec2 fragCoord)
{
    vec2 uv=(0.5+fragCoord.xy)/iResolution.xy;

    vec4 clraverge=vec4(0.0);
    float GlowRange=40.0;   // 半徑
    float GlowExpand=0.0;   // 角度
    float samplerPre=1.0;
    float range=GlowRange*0.2;
    float rad=PI/180.0*GlowExpand;
    for(float j = 1.0; j <= range; j+=samplerPre){
        float dx=0.002*cos(rad);
        float dy=0.002*sin(rad);
        vec2 samplerTexCoord = vec2(uv.x+j*dx, uv.y+j*dy);
        vec2 samplerTexCoord1= vec2(uv.x-j*dx, uv.y-j*dy);
        if( samplerTexCoord.x < 0.0 || samplerTexCoord.x > 1.0 || 
            samplerTexCoord1.x < 0.0 || samplerTexCoord1.x > 1.0 ||
            samplerTexCoord.y < 0.0 || samplerTexCoord.y > 1.0 || 
            samplerTexCoord1.y < 0.0 || samplerTexCoord1.y > 1.0) {
            continue;
        }
        vec4 tc= texture2D(iChannel1, samplerTexCoord);
        vec4 tc1= texture2D(iChannel1, samplerTexCoord1);
        clraverge+=tc;
        clraverge+=tc1;
    }
    clraverge/=(range*2.0/samplerPre);
    fragColor=clraverge;
}

原圖如下：

效果圖如下：