刷新着色器，尝试使其在处理中刷新

问题描述

我正在寻找sobel着色器，它将允许我更改倍增器。

我发现了以下内容 https://forum.processing.org/two/discussion/21746/multipass-shader-example https://github.com/cansik/processing-postfx

，并使用了提供的以下着色器，但是着色器不会刷新。 现在，处理示例中的默认边缘检测确实允许刷新，但是会产生质量较差的边缘检测。

我想适应的代码

// Adapted from:
// <a href="http://callumhay.blogspot.com/2010/09/gaussian-blur-shader-glsl.html" target="_blank" rel="nofollow">http://callumhay.blogspot.com/2010/09/gaussian-blur-shader-glsl.html</a>
 
#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif
 
#define PROCESSING_TEXTURE_SHADER
 
uniform sampler2D texture;
uniform float mult;
 
varying vec4 vertColor;
varying vec4 vertTexCoord;

uniform vec2 resolution;

void main(void) {
  float x = 1.0 / resolution.x;
  float y = 1.0 / resolution.y;
  
  
  vec4 horizEdge = vec4( 0.0 );
  horizEdge -= texture2D( texture,vec2( vertTexCoord.x - x,vertTexCoord.y - y ) ) * 1.0;
  horizEdge -= texture2D( texture,vertTexCoord.y     ) ) * 2.0;
  horizEdge -= texture2D( texture,vertTexCoord.y + y ) ) * 1.0;
  horizEdge += texture2D( texture,vec2( vertTexCoord.x + x,vertTexCoord.y - y ) ) * 1.0;
  horizEdge += texture2D( texture,vertTexCoord.y     ) ) * 2.0;
  horizEdge += texture2D( texture,vertTexCoord.y + y ) ) * 1.0;
  
  vec4 vertEdge = vec4( 0.0 );
  vertEdge -= texture2D( texture,vertTexCoord.y - y ) ) * 1.0;
  vertEdge -= texture2D( texture,vec2( vertTexCoord.x,vertTexCoord.y - y ) ) * 2.0;
  vertEdge -= texture2D( texture,vertTexCoord.y - y ) ) * 1.0;
  vertEdge += texture2D( texture,vertTexCoord.y + y ) ) * 1.0;
  vertEdge += texture2D( texture,vertTexCoord.y + y ) ) * 2.0;
  vertEdge += texture2D( texture,vertTexCoord.y + y ) ) * 1.0;
  
  vec3 edge = sqrt((horizEdge.rgb * horizEdge.rgb) + (vertEdge.rgb * vertEdge.rgb));
  
  float col = (edge.x+edge.y+edge.z)/3;
  
  gl_FragColor = vec4(1.0,1.0,col)*mult;
}

正在处理的示例代码

#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif

#define PROCESSING_TEXTURE_SHADER

uniform sampler2D texture;
uniform vec2 texOffset;

varying vec4 vertColor;
varying vec4 vertTexCoord;

void main(void) {
  // Grouping texcoord variables in order to make it work in the GMA 950. See post #13
  // in this thread:
  // http://www.idevgames.com/forums/thread-3467.html
  vec2 tc0 = vertTexCoord.st + vec2(-texOffset.s,-texOffset.t);
  vec2 tc1 = vertTexCoord.st + vec2(         0.0,-texOffset.t);
  vec2 tc2 = vertTexCoord.st + vec2(+texOffset.s,-texOffset.t);
  vec2 tc3 = vertTexCoord.st + vec2(-texOffset.s,0.0);
  vec2 tc4 = vertTexCoord.st + vec2(         0.0,0.0);
  vec2 tc5 = vertTexCoord.st + vec2(+texOffset.s,0.0);
  vec2 tc6 = vertTexCoord.st + vec2(-texOffset.s,+texOffset.t);
  vec2 tc7 = vertTexCoord.st + vec2(         0.0,+texOffset.t);
  vec2 tc8 = vertTexCoord.st + vec2(+texOffset.s,+texOffset.t);
  
  vec4 col0 = texture2D(texture,tc0);
  vec4 col1 = texture2D(texture,tc1);
  vec4 col2 = texture2D(texture,tc2);
  vec4 col3 = texture2D(texture,tc3);
  vec4 col4 = texture2D(texture,tc4);
  vec4 col5 = texture2D(texture,tc5);
  vec4 col6 = texture2D(texture,tc6);
  vec4 col7 = texture2D(texture,tc7);
  vec4 col8 = texture2D(texture,tc8);

  vec4 sum = 8.0 * col4 - (col0 + col1 + col2 + col3 + col5 + col6 + col7 + col8); 
  gl_FragColor = vec4(sum.rgb,1.0) * vertColor;
}

我想添加的地方

uniform float mult;

float col = (sum.r+sum.g+sum.b)/3;

，还有gl_FragColor。

gl_FragColor = vec4(1.0,col) * mult;

我也看过了着色器玩具，但是由于它们总是会产生很多错误，因此还不了解如何使用提供的着色器。

我也尝试过自己制作，但无法正常运行。

#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif

#define PROCESSING_TEXTURE_SHADER

uniform sampler2D texture;
uniform vec2 texOffset;
uniform float mult;
uniform float range;

varying vec4 vertColor;
varying vec4 vertTexCoord;

const mat3 sobelH = mat3(-1,-2,-1,1,2,1);
const mat3 sobelV = mat3(-1,1);


void main(void) {
  
    float x = gl_FragCoord.x;
    float y = gl_FragCoord.y;
    
    float sh = 0.0;
    float sv = 0.0;

    vec2 tc;
    vec4 myPixel = texture2D(texture,vertTexCoord.st);
    float myCol = (myPixel.x+myPixel.y+myPixel.z+myPixel.a)/4.0;
    float count = 0.0;
  
    for (float i = x -  range; i <= x +range; i+=1.0) { 
        for (float j = y -  range; j <= y +range; j+=1.0) { 
        
        tc = vec2(i,j);

        vec4 col = texture2D(texture,tc);
        float b = (col.a + col.r + col.g + col.b)/4.0;

        float x1 = 0 + i - x + 1;
        float y1 = 0 + j - y + 1;
        
        float h = sobelH[x1][y1] * b;
        float v = sobelV[x1][y1] * b;
        
        float sv+= v;
        float sh+= h;
        
    }}
    
    float vx = 8 * myCol - sh;
    float vy = 8 * myCol - sv;
    float val = sqrt(vx,*vx+vy*vy);
    gl_FragColor = vec4((val),(val),(1.0));
};

作为参考，这是我移动鼠标时当前顶部着色器的功能

解决方法

gl_FragColor = vec4（1.0,1.0,1.0）* 1 /（（（col * mult））;