Hi I am trying to pass 2 textures to a shader and I am a little confused about the working here
This is the opengl code
GLuint textures;
GLuint textures1;
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=glGetUniformLocationARB(programObjectFloor,"Tex1");
GLuint location2=glGetUniformLocationARB(programObjectFloor,"Tex2");
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D,textures);
glUniform1i(location1, 0);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D,textures1);
glUniform1i(location2, 1);
the vertex shader is
attribute vec4 position;
attribute vec4 texture;
uniform mat4 MVP;
varying vec4 ptexture;
void main()
{
ptexture = texture;
gl_Position = MVP * position;
}
the fragment shader is
varying vec4 ptexture;
uniform sampler2D Tex1;
uniform sampler2D Tex2;
uniform bool swit;
void main()
{
gl_FragColor = texture2D(Tex1,ptexture.st);
}
In my fragment shader, when I change my code to the below, still only the first texture is displayed.
varying vec4 ptexture;
uniform sampler2D Tex1;
uniform sampler2D Tex2;
uniform bool swit;
void main()
{
gl_FragColor = texture2D(Tex2,ptexture.st);
}
But when I comment out the opengl code as shown below, the second texture is shown
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=glGetUniformLocationARB(programObjectFloor,"Tex1");
GLuint location2=glGetUniformLocationARB(programObjectFloor,"Tex2");
// glActiveTexture(GL_TEXTURE0);
// glBindTexture(GL_TEXTURE_2D,textures);
// glUniform1i(location1, 0);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D,textures1);
glUniform1i(location2, 1);
this line below in the fragment shader does not affect the rendering in anyway
gl_FragColor = texture2D(Tex2,ptexture.st);
i can mention Tex1 or Tex2 and it still displays some texture, I am totally confused, it would be great if someone could explain what is happening.
Thanks!!