GLSL-两个纹理（不混合）

Question

我正在用GLSL处理纹理。我如何用GLSL处理两个纹理？一个人推荐我在我的GLSL中做两个采样2D...但是GLSL如何知道2D应该使用哪些采样器呢？（我不是在说混合纹理...）

我听说我应该使用glbindtexture。我怎么能这么做？用glbindtexture？有人有这方面的例子吗？

uniform Sampler2D texture1;
uniform Sampler2D texture2;

Answer 1

您需要将每个纹理绑定到不同的纹理单元，然后使用多纹理库。它看起来如下所示（假设您已经有了纹理）：

glActiveTexture (GL_TEXTURE0);  // First texture is going into texture unit 0
glBindTexture (GL_TEXTURE_2D, tex0);
glEnable (GL_TEXTURE_2D);

glActiveTexture (GL_TEXTURE1);  // Second texture is going into texture unit 1
glBindTexture (GL_TEXTURE2D, tex1);
glEnable (GL_TEXTURE_2D);

glUseProgram (yourGLSLProgramID);
glUniform1i (sampler1Location, 0); // tell glsl that sampler 1 is sampling the texture in texture unit 0
glUniform1i (sampler2Location, 1); // tell glsl that sampler 2 is sampling the texture in texture unit 1
///... set the rest of your uniforms...

glBegin (GL_QUADS);
    glMultiTexCoord2f(GL_TEXTURE0, 0.0, 0.0);
    glMultiTexCoord2f(GL_TEXTURE1, 0.0, 0.0);
    glVertexCoord2f(0.0, 0.0);

    glMultiTexCoord2f(GL_TEXTURE0, 1.0, 0.0);
    glMultiTexCoord2f(GL_TEXTURE1, 1.0, 0.0);
    glVertexCoord2f(width, 0.0);

    glMultiTexCoord2f(GL_TEXTURE0, 1.0, 1.0);
    glMultiTexCoord2f(GL_TEXTURE1, 1.0, 1.0);
    glVertexCoord2f(width, height);

    glMultiTexCoord2f(GL_TEXTURE0, 0.0, 1.0);
    glMultiTexCoord2f(GL_TEXTURE1, 0.0, 1.0);
    glVertexCoord2f(0.0, height);
glEnd();