Step by Step solution about How to resolve the algorithm OpenGL step by step in the Haskell programming language

This code is a simple OpenGL program that draws a triangle on the screen. It uses the Haskell bindings for OpenGL and GLUT, which are libraries for creating and managing graphics windows.

The main function first calls getArgsAndInitialize to initialize the OpenGL context and create a window. It then sets the display callback to the display function, which will be called whenever the window needs to be redrawn.

The display function clears the color buffer and then renders a triangle using the renderPrimitive function. The triangle is defined by three vertices, which are specified by the corner function. The corner function takes three arguments: the red, green, and blue components of the vertex color, and the x and y coordinates of the vertex.

Finally, the mainLoop function is called to start the main event loop. The event loop listens for events such as mouse clicks and keyboard presses, and calls the appropriate callback functions to handle them.

Here is a more detailed explanation of the code:

• The import statements at the beginning of the code import the necessary libraries.
• The main function is the entry point of the program. It calls getArgsAndInitialize to initialize the OpenGL context and create a window. It then sets the display callback to the display function, which will be called whenever the window needs to be redrawn.
• The display function clears the color buffer and then renders a triangle using the renderPrimitive function. The triangle is defined by three vertices, which are specified by the corner function. The corner function takes three arguments: the red, green, and blue components of the vertex color, and the x and y coordinates of the vertex.
• The mainLoop function is called to start the main event loop. The event loop listens for events such as mouse clicks and keyboard presses, and calls the appropriate callback functions to handle them.

import Graphics.Rendering.OpenGL
import Graphics.UI.GLUT

main = do
  getArgsAndInitialize
  createWindow "Triangle"
  displayCallback $= display
      
  matrixMode $= Projection
  loadIdentity
  ortho2D 0 30 0 30
  matrixMode $= Modelview 0
  
  mainLoop

display = do
  clear [ColorBuffer]
  renderPrimitive Triangles $ do
    corner 1 0 0 5 5
    corner 0 1 0 25 5
    corner 0 0 1 5 25
  swapBuffers
       
corner r g b x y = do color  (Color3  r g b :: Color3  GLfloat)
                      vertex (Vertex2 x y   :: Vertex2 GLfloat)