OpenGL着色器GLSL中的颜色逐位移位

时间:2014-12-18 13:54:49

标签: c++ opengl glsl fragment-shader

我将vec4传递给带有xyz和颜色值的着色器,我尝试按比例将颜色组件移动到它们自己的r g和b浮动但是有问题:

顶点着色器:

#version 150

in vec4 position;

out vec2 Texcoord;

uniform mat4 model;
uniform mat4 view;
uniform mat4 proj;

void main()
{
    Texcoord = vec2(position.w, position.w);
    gl_Position = proj * view * model * vec4(position.xyz, 1.0);
} 

片段着色器:

#version 150

in vec2 Texcoord;
out vec4 outColor;

uniform sampler2D tex;

void main()
{
    float data = Texcoord.r;
    float r = (data>> 16) & 0xff;
    float g = (data>> 8) & 0xff;
    float b = data & 0xff;
    outColor = vec4(r, g, b, 1.0);
}

错误:

Error compiling shader: 
0(11) : error C1021: operands to ">>" must be integral
0(12) : error C1021: operands to ">>" must be integral
0(13) : error C1021: operands to "&" must be integral

任何想法我做错了什么?

1 个答案:

答案 0 :(得分:3)

确定完成了:)

#version 150

in vec2 Texcoord;
out vec4 outColor;

uniform sampler2D tex;

vec3 unpackColor(float f) 
{
    vec3 color;
    color.r = floor(f / 65536);
    color.g = floor((f - color.r * 65536) / 256.0);
    color.b = floor(f - color.r * 65536 - color.g * 256.0);
    return color / 256.0;
}

void main()
{
    float data = Texcoord.r;
    vec3 unpackedValues = unpackColor(Texcoord.r);

    outColor = vec4(unpackedValues.bgr, 1.0);
}

我将4位构造传递到点云中点的x和z坐标,第4个值是浮点数中的编码颜色。所以我需要从浮点数中提取rgb信息,为每个点提供一种颜色。

感谢您的帮助:)