OpenGL using Texture2d key steps

Steps to generate texture2d
1. Prepare the pixel data for the texture ImageData
2. Glgentextures (); stored in a handle gluint texture
3. Glbindtexture () The Texture just generated, the first parameter is gl_texture_2d
4. Glteximage2d (), combined with imageData and the texture that was just bound, so the texture generation is complete.
5. Clean up ImageData memory
6. Glbindtexture () The first parameter is gl_texture_2d, and the second one is 0. And just the texture handle unbound




Gluint generatetexture (std::string filePath)
{
int width, height;
unsigned char* image = Soil_load_image (Filepath.c_str (), &width, &height, 0, Soil_load_rgb);
Gluint texture;
Glgentextures (1, &texture);
Glbindtexture (gl_texture_2d, TEXTURE);
Glteximage2d (gl_texture_2d, 0, Gl_rgb, width, height, 0, Gl_rgb, gl_unsigned_byte, image);
Glgeneratemipmap (gl_texture_2d);
Soil_free_image_data (image);
Glbindtexture (gl_texture_2d, 0);
return texture;
}


7. When using textures


Glactivetexture (GL_TEXTURE0);
Glbindtexture (gl_texture_2d, TEXTURE);
Gluniform1i (Glgetuniformlocation (Shaderprogram, "Outtexture"), 0);


Glactivetexture (Gl_texture1);
Glbindtexture (gl_texture_2d, TEXTURE);
Gluniform1i (Glgetuniformlocation (Shaderprogram, "OutTexture1"), 1);


The last parameter of gluniform1i () 0,1 refers to sampler2d corresponding gl_texture0 in shader, Gl_texture1




The corresponding fragment shader:


#version Core
Out VEC4 color;
In Vec4 Vertexcolor;
In VEC2 Texcoord;
Uniform sampler2d outtexture;
Uniform sampler2d OutTexture2;
void Main ()
{
"COLOR = Mix (texture (outtexture,texcoord), Texture (Outtexture2,texcoord), 0.2);"
}