Open. GL GUI Application.This article is about a MVC Model View Controller framework to create Open.FileDownloadHandler.png' alt='Extract Text From Windows Application Event' title='Extract Text From Windows Application Event' />Loading DocCommentXchange.Loading DocCommentXchange.GL GUI applications on Windows platform.MVC architecture is a common design framework for GUI applications, and is used in many GUI libraries, such as.NET, MFC, Qt, Java.Im required to log my start and finish times at work.Occasionally I forget to do this and had a bright idea that checking the Security events log would allow me to.PowerShell including Windows PowerShell and PowerShell Core is a task automation and configuration management framework from Microsoft, consisting of a commandline.Extract Text From Windows Application Event' title='Extract Text From Windows Application Event' />FX, etc.The major benefits of this MVC framework are the complete separation of system independent Open.GL calls from Windows system and the universal message router for multiple windows.Download gl. Win.Simple. zip, gl. Win.Orbit. Camera. Overview.MVC paradigm is to divide an application into 3 separate components Model, View and Controller components in order to minimize dependencies between them.Model component is the brain part of the application, which contains all application data and implementations to tell how the application behaves.More importantly, Model component does not have any reference to View or Controller component, which means Model component is purely independent.It does not know which Controller or View component is associated with.Model component simply processes the requests from any Controller or View component.View component is responsible to render the visual contents onto the screen.Also, View module does not have any reference to Controller component independent on Controller.It only performs rendering process when any Controller component requests to update the visual.However, View component should reference to a certain Model component, because it must know where to obtain the data from, so, it can render the data on the screen.Controller component is the bridge between users and the application by receiving and handling all user events, such as keyboard and mouse inputs.Extract Text From Windows Application Event' title='Extract Text From Windows Application Event' />This module should know which Model and View component to access.In order to handle a user event, Controller component requests Model to process the new data, and at the same time, tells View component to update the visuals.Here is a very simple scenario.Imagine that you make a currency conversion program from Canadian dollars to US dollars.When a user click Convert button, what should your application do Controller gets the button click event first.Controller sends the input value to Model and requests the conversion.Model converts the input to US dollars and save the result.Controller requests View to display the result.View gets the result from Model.View displays the result on the screen.The major advantages of MVC design are clarity and modularity.Since MVC paradigm cleanly separates an application into 3 logical components, it is cleaner and easier to understand the role of each component, and to maintain each module separately by multiple developers.Because of its efficient modularity, the components can be interchangeable and scalable.For example, you can customize the look and feel of View component without modifying Model and Controller modules, or can add multiple different views table and chart simultaneously.Example 1 gl. Win.Simple. This is a single window Open.GL application. It does not have GUI controls except mouse interaction.However, this example is better to understand how to implement the MVC design to an Open.GL application. Then, we will discuss with more complex example in the following section.Get the source and binary 6.Win. Simple. zipUpdated 2.Visual. Studio 2.This application consists of 3 separate C classes, Model.GL, View. GL and Controller.GL. For Open. GL application, all system independent Open.GL commands can be placed in the Model.GL component, so, Model component itself can be re usable for other platforms such as mac.OS without any modification.Therefore, Model is purely independent on Controller and View modules.View component is for rendering the visual onto screen.Therefore, all display device properties rendering context, colour bits, etc go into this component.Also, system specific Open.GL commands are placed in this component, such as wgl.Create. Context and wgl.Make. Current. Again, View component does not reference to Controller independent on Controller, but may need to reference to Model, for instance, to get Models data to update View contents.Controller component is for receiving all user events first, then, updates Models states, and notifies to View component to render the scene.It has the basic input handling functions for keyboard escape key and mouse leftright buttons.Please look at the the source code in Controller.GL class key. Down, l.Button. Down, r. Button.Down, mouse. Move, etc.Controller. GL class is derived from the base class of Controller.You can simply add event handlers into Controller.GL class if you need to override the default behaviors.These 3 objects are created in main, and then, a single window is created with the reference pointer to the Controller.GL object. I used a helper class, Window.Notice that the main function remains very simple, and all detailed implementations are moved to 3 separate components Model.GL, View. GL and Controller.GL. int WINAPI Win.Main. Model. GL model.Win View. GL view.Win Controller. GL gl.Ctrl model, view.Win Window gl. Winh.Inst, Lgl. Win. Simple, 0, gl.Ctrl. gl. Win. set.Window. StyleWSOVERLAPPEDWINDOW WSVISIBLE.WSCLIPSIBLINGS WSCLIPCHILDREN.Win. set. Class. StyleCSOWNDC.Win. set. Width4.Win. set. Height3.Win. create. gl. Win.Code. exit. Code main.Message. Loop. return exit.Code. Create Open.GL window. Creating an Open.GL window is same as creating other generic windows except Open.GL rendering context RC.The Open. GL rendering context is a port to link Open.GL to Windows system.All Open. GL commands can pass through this rendering context.The rendering context must be associated with a device context DC which has same pixel format as RC has, so, Open.GL drawing can take place on the device surface.In your WMCREATE handler, you can create a RC.Get the DC of the Open.GL window with Get.DC and the window handle.Set the desired pixel format with Set.Pixel. Format and the DC.Create new RC with wgl.Create. Context and the DC.Release the DC with Release.DC. In your WMCLOSE handler, you can delete the RC.Release the current RC with wgl.Make. Current and NULL parameter.Delete the RC with wgl.Delete. Context. In your rendering loop, set the rendering context as the current RC with wgl.Make. Current before calling any Open.GL commands. I use a separate worker thread for the rendering loop.Plese see the following section, Separate thread for rendering Open.GL. Finding a desired pixel format can be done by searching all available formats using Describe.Pixel. Format. A standard scoring mechanism to find the best pixel format is described in find.Pixel. Format method in View.GL class. int find.Pixel. FormatHDC hdc, int color.Bits, int depth. Bits, int stencil.Bits. int curr. Mode.Mode. int curr. Score.Score. PIXELFORMATDESCRIPTOR pfd.Mode 0. best. Score 0.Mode 1. Describe.Pixel. Formathdc, curr.Mode, sizeofpfd, pfd 0.Mode. ifpfd. dw. Flags PFDSUPPORTOPENGL.Flags PFDDRAWTOWINDOW.Pixel. Type PFDTYPERGBA.Flags PFDNEEDPALETTE.Flags PFDDOUBLEBUFFER.Score 0. ifpfd. Color.Bits color. Bits curr.Score. Color. Bits color.Bits curr. Score.Depth. Bits depth. Google Earth Installer The Download Failed Resources . Bits curr. Score.Depth. Bits depth.Bits curr. Score.Stencil. Bits stencil.Bits curr. Score.Stencil. Bits stencil.Bits curr. Score.Alpha. Bits 0 curr.Score. ifcurr. Score best.Score. best. Score curr.Score. best. Mode curr.Mode. return best.Mode. Separate thread for rendering Open.GL. MS Windows is an event driven system.An event driven windows application will rest without doing anything if there is no event triggered.However, Open. GL rendering window may need to be constantly updated even if no event coming to the application.One of solutions for constant updating Open.GL window is using Peek.Message in the window message loop.Message. Loop. if Peek.Message msg, 0, 0, 0, PMREMOVE.WMQUIT. break. else.Translate. Message msg.Dispatch. Message msg.Param. However, there is a better solution using a separate worker thread for Open.
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