OpenGL Notes

glNotes.c

/*
    CREATING THE VAO & VBO
    ======================
    Objects must be generated via its corresponding glGen...() function
    To perform any operations on any of OpenGL's objects, we must bind
    the objects by invoking it corresponding glBind...() function
        
    For @param GLenum target:
        GL_ARRAY_BUFFER for Vertex attributes (Non-indexing method)
        GL_ELEMENT_ARRAY_BUFFER for Vertex array indices (Indexing method)
*/
glGenVertexArrays(GLsizei n, GLuint *arrays);
glBindVertexArrays(GLuint array);
glGenBuffers(GLsizei n, GLuint *buffer);
glBindBuffers(GLenum target, GLuint buffer);

/* 
    Once the objects are created, we can populate data into it
    by calling glBufferData() we "move" the data from Normal RAM to the GPU's RAM (Not too sure about this analogy)
        
    If the data is custom, we must specify to OpenGL how it should interpret it
    via glVertexAttribPointer() 
    
    Once we are done using something in OpenGL, we should unbind it:
    Use the input argument of 0 to specify unbinding the currently binded object
*/
glBufferData(GLenum target, GLsizeiptr size, const GLvoid *data, GLenum usage);
glVertexAttribPointer(GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid * pointer);

//Unbinding the current VAO/VBO
glBindBuffers(GLenum target, 0);
glBindVertexArrays(0);

/*
    USING AND DESTROYING THE VAO & VBO
    ==================================
    To use the VAO/VBO again we must bind it, and unbind it once we're done
    After binding we can enable a VAO's attribute(s), and disable it once we're done
    If there are multiple attributes, make sure to activate more than one
    
    For every attribute (VBO) and VAO you've generated, you must call its corresponding
    glDelete...() to release the memory they held which properly destroys it
*/
glBindVertexArray(GLuint array);
glEnableVertexAttribArray(GLuint index);
    //Attrubutes are activated, do something...like draw a shape...
    glDrawElements(GLenum mode, GLsizei count, GLenum type, const GLvoid *indices);
glDisableVertexAttribArray(GLuint index);
glBindVertexArray(0);

//Clearing up the VAO/VBO in the application's destructor
glDeleteVertexArray(vao);
glDeleteBuffers(vbo);



//-----Creating Shaders and Shader Programs-----
//For every shader (Vertex, Fragment, Geometric...)
    glCreateShader();
    glShaderSource();
    glCompileShader();

glCreateProgram();
//For every shader relating to each other:
    glAttachShader();
//For every uniform variable:
    glBindAttribLocation();
glLinkProgram();
glValidateProgram();


//-----Helpful validation for Shaders-----
glGetProgrami();
glGetProgramInfoLog();


//-----Using the Shader-----
glUseProgram(programID);
//Do some rendering...
glUseProgram(0);


//-----Destroying the Shader
//Per every shader in the program:
    glDetachShader(prog, shader);
    glDeleteShader(shaderID);
    glDeleteProgram(programID);



//-----Creating the Texture-----
glGenTexture();
glBindTexture();
//For every parameter:
    glTexParameter();
glTexImage();


//-----Using the texture-----
//(In the render method, right before drawing)
glActiveTexture();
glBindTexture();


//-----Destroying the Shader-----
glDeleteTexture();