这是我当前使用的着色器。它通过缓慢降低不透明度来淡化对象。我想褪成紫色。如何才能做到这一点?
着色器.frag:
uniform sampler2D texture;
uniform float opacity;
void main()
{
vec4 pixel = texture2D(texture, gl_TexCoord[0].xy);
gl_FragColor = pixel * vec4(1.0, 1.0, 1.0, opacity);
}
着色器.vert:
void main()
{
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0;
gl_FrontColor = gl_Color;
}
Shader在main函数中的应用:
sf::Shader shader;
if (!shader.loadFromFile("shader.vert", "shader.frag"))
return EXIT_FAILURE;
float opacity = 1.0; //transparency of shader
shader.setParameter("texture", sf::Shader::CurrentTexture); //shader.vert
shader.setParameter("opacity", opacity); //shader.frag
///////////////////////////////////////////////////////
//Delete Text Display
counter1 = 0;
for (iter8 = textDisplayArray.begin(); iter8 != textDisplayArray.end(); iter8++)
{
if (textDisplayArray[counter1].destroy == true)
{
//shader
opacity -= 0.1;
if (opacity <= 0)
{
textDisplayArray.erase(iter8);
opacity = 1;
}
shader.setParameter("opacity", opacity);
}