我正在尝试将 2 个纹理传递给着色器,但我对这里的工作有点困惑这是 opengl 代码
GLuint textures;
GLuint textures1;</code>
glGenTextures(1,&textures);
glGenTextures(1,&textures1);
glBindTexture(GL_TEXTURE_2D,textures);
glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,256,256,0,GL_RGB,GL_UNSIGNED_BYTE,texImg);
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
glBindTexture(GL_TEXTURE_2D,textures1);
glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,256,256,0,GL_RGB,GL_UNSIGNED_BYTE,texImg1);
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
glBindTexture(GL_TEXTURE_2D,textures1);
GLuint location1=glGetUniformLocation(programObjectFloor,"Tex1");
GLuint location2=glGetUniformLocation(programObjectFloor,"Tex2");
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D,textures1);
glUniform1i(location2, 1);
glActiveTexture(GL_TEXTURE0);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D,textures);
glUniform1i(location1, 0);
顶点着色器是
attribute vec4 position;
attribute vec4 texture;
uniform mat4 MVP;
varying vec4 ptexture;
void main()
{
ptexture = texture;
gl_Position = MVP * position;
}
片段着色器是
varying vec4 ptexture;
uniform sampler2D Tex1;
uniform sampler2D Tex2;
uniform bool swit;
void main()
{
gl_FragColor = texture2D(Tex1,ptexture.st);
}
当我换线时
gl_FragColor = texture2D(Tex2,ptexture.st);
仍然只显示第一个纹理,但是当我注释掉下面的行时,显示了第二个纹理,你能解释一下为什么会这样吗?
// glActiveTexture(GL_TEXTURE0);
// glEnable(GL_TEXTURE_2D);
// glBindTexture(GL_TEXTURE_2D,textures);
// glUniform1i(location1, 0);