以下是一个基本的边缘检测着色器的代码示例，其中传递了3个顶点位置给着色器程序。

顶点着色器代码示例：

#version 330 core

layout (location = 0) in vec3 position;

void main()
{
    gl_Position = vec4(position, 1.0);
}

片段着色器代码示例：

#version 330 core

out vec4 FragColor;

uniform vec2 resolution;

void main()
{
    vec2 texelSize = 1.0 / resolution;

    vec4 color = vec4(0.0, 0.0, 0.0, 1.0);

    vec2 texCoord = gl_FragCoord.xy * texelSize;

    vec2 offset1 = vec2(-1.0, -1.0) * texelSize;
    vec2 offset2 = vec2( 0.0, -1.0) * texelSize;
    vec2 offset3 = vec2( 1.0, -1.0) * texelSize;
    vec2 offset4 = vec2(-1.0,  0.0) * texelSize;
    vec2 offset5 = vec2( 1.0,  0.0) * texelSize;
    vec2 offset6 = vec2(-1.0,  1.0) * texelSize;
    vec2 offset7 = vec2( 0.0,  1.0) * texelSize;
    vec2 offset8 = vec2( 1.0,  1.0) * texelSize;

    vec4 color1 = texture(sampler, texCoord + offset1);
    vec4 color2 = texture(sampler, texCoord + offset2);
    vec4 color3 = texture(sampler, texCoord + offset3);
    vec4 color4 = texture(sampler, texCoord + offset4);
    vec4 color5 = texture(sampler, texCoord + offset5);
    vec4 color6 = texture(sampler, texCoord + offset6);
    vec4 color7 = texture(sampler, texCoord + offset7);
    vec4 color8 = texture(sampler, texCoord + offset8);

    float edge = length(color1.rgb - color8.rgb) +
                 length(color2.rgb - color7.rgb) +
                 length(color3.rgb - color6.rgb) +
                 length(color4.rgb - color5.rgb);

    FragColor = vec4(edge, edge, edge, 1.0);
}

请注意，这只是一个简单的边缘检测着色器示例，实际应用中可能需要根据需求进行修改。在这个示例中，通过计算相邻像素的颜色差异，将边缘区域着色为白色。