Chapter 1, Introduction to OpenGL

• You should read chapter 1.
• OpenGL Syntax
  • Functions
    • glFunctionName are OpenGL functions.
      • These are mostly graphics calls.
      • glDrawArrays is an instruction to draw something.
      • In general, OpenGL interacts with the GPU.
      • OpenGL is covered throughout the book.
    • glutFunctionName are glut functions.
      • Two types
      • glutCreateWindow interacts with the OS to create a main window.
      • glutDisplayFunc tells glut what to call when the image needs rediplayed.
      • In general, glut interacts with the operating system.
      • glut is covered in appendix A.
  • Constants
    • GL_COLOR_BUFFER_BIT - this refers to the color bits in the frame buffer.
    • GLUT_KEY_DOWN refers to a key press event.
  • To be more portable, OpenGL has a set of type definitions.
    • GLfloat is the floating point type. (See table 1, page 10)
    • This is a C library, so there is not function overloading based on type.
      • Many functions have multiple versions.
      • glColor*
        • 3 or 4
        • b,s,i,f,d,ub,us,ui
        • glColor3ui()
• The OpenGL Pipeline
  • 
  • Specifying data (Vertex Data) is somewhat complex.
    • Chapter 3 is all about this.
    • Probably more time than we want to spend.
    • But probably the most basic for an OpenGL literate person.
    • This is most (or all) of the task accomplished in the init function.
  • Shaders
    • Programmable portions of the pipeline.
    • Allow users to implement portions of the graphics pipeline.
    • We need to provide Vertex and Fragment shaders. All others are optional.
  • Other parts: Primitive Setup, Clipping, Rasterization
    • We have seen parts of this.