替换 HLSL 着色器中的特定颜色

问：

我正在尝试编辑现有的着色器，使其仅适用于 1 种颜色，然后制作它，以便这 1 种颜色可以替换为不同的颜色。

这是原始代码

sampler s0 : register(s0);
float4 p0 : register(c0);
float4 p1 : register(c1);

#define width (p0[0])
#define height (p0[1])
#define counter (p0[2])
#define clock (p0[3])
#define one_over_width (p1[0])
#define one_over_height (p1[1])

#define PI acos(-1)
#define cutoffR 0.40
#define cutoffG 0.025
#define cutoffB 0.25
#define cutoffY 0.25
#define acceptanceAmplification 5

#define showR 1
#define showG 1
#define showB 1
#define showY 1

float4 main(float2 tex : TEXCOORD0) : COLOR
{
    float4 color = tex2D(s0, tex);

    float luminance = (color.r + color.g + color.b)/3;
    float4 gray = {luminance,luminance,luminance, 1};

    float redness       = max ( min ( color.r - color.g , color.r - color.b ) / color.r , 0);
    float blueness      = max ( min ( color.b - color.r , color.b - color.g ) / color.b , 0);
    float greenness     = max ( min ( color.g - redness, color.g - blueness), 0);
    
    float rgLuminance = (color.r*1.4 + color.g*0.6)/2;
    float rgDiff = abs(color.r-color.g)*1.4;

    float yellowness = 0.1+rgLuminance*1.2 - color.b - rgDiff;

    float4 accept;
    accept.r  = showR * (redness - cutoffR);
    accept.g  = showG * (greenness - cutoffG);
    accept.b  = showB * (blueness - cutoffB);
    accept[3] = showY * (yellowness - cutoffY);

    float acceptance = max (accept.r, max(accept.g, max(accept.b, max(accept[3],0))));
    float modAcceptance = min (acceptance * acceptanceAmplification, 1);

    float4 result;
    result = modAcceptance * gray + (1.0-modAcceptance) * color;

    return result;
}

来源 ： github

我改变了

#define cutoffR 0.40
#define cutoffG 0.025
#define cutoffB 0.25
#define cutoffY 0.25

自

#define cutoffR 1
#define cutoffG 1
#define clip(B) 0.25
#define cutoffY 1

因此，它只影响蓝色，因为我试图将蓝色变成紫色。现在它正在变成蓝色，我不知道如何进一步进行。

我稍微更改了代码

sampler s0 : register(s0);
float4 p0 : register(c0);
float4 p1 : register(c1);

#define width (p0[0])
#define height (p0[1])
#define counter (p0[2])
#define clock (p0[3])
#define one_over_width (p1[0])
#define one_over_height (p1[1])

#define PI acos(-1)
#define cutoffR 1
#define cutoffG 1
#define clip(B) 0.25
#define cutoffY 1
#define acceptanceAmplification 5

#define showR 1
#define showG 1
#define showB 1
#define showY 1

float4 main(float2 tex : TEXCOORD0) : COLOR
{
    float4 color = tex2D(s0, tex);

    float luminance = (color.r + color.g + color.b)/3;
    float4 color2 = (0);

    float redness       = max ( min ( color.r - color.g , color.r - color.b ) / color.r , 0);
    float blueness      = max ( min ( color.b - color.r , color.b - color.g ) / color.b , 0);
    float greenness     = max ( min ( color.g - redness, color.g - blueness), 0);
    
        


    float4 accept;
    accept.r  = showR * (redness - cutoffR);
    accept.g  = showG * (greenness - cutoffG);
    accept.b  = showB * (blueness - clip(B));


    float acceptance = max (accept.r, max(accept.g, max(accept.b,(0))));
    float modAcceptance = min (acceptance * acceptanceAmplification, 1);

    float4 result;
    result = modAcceptance * color2 + (1.0-modAcceptance) * color;

    return result;
}

交换

float rgDiff = abs(color.r-color.g)*1.4; 

自

float4 color2 = (0);

和

result = modAcceptance * gray + (1.0-modAcceptance) * color;

自

result = modAcceptance * color2 + (1.0-modAcceptance) * color;

我现在可以在 color2 = （） 中输入一个介于 0-1 之间的值，该值将颜色从黑色更改为白色，但仅此而已。我不知道如何将其替换为特定颜色。