I want to draw temporary items to indicate user actions eg a line from a given location to the current mouse location which will update very quickly as the mouse moves. In the past I have used a GDI overlay approach which fails in newer graphics cards.
Windows seems not to support an Overlay Buffer.
Any suggestions how I can draw and update fast temporary lines onto an Windows OpenGL window without re rendering the whole screen?
There is no shader required. Just render your normal scene into a texture, e.g. using a framebufferobject (FBO). Every time you need to update your "overlay" render that texture using a screen size quad and render your overlay above it.
However, normally there are not that many mouse events. If your scene is not unusual complex you can simply redraw everything each time.
I have been using the complete scene redraw combined with the use of display lists, but as the scenes get more complex, the redraws do get to be too slow. I need to be able to "rubber band" the mouse line as the mouse moves. The user is building the scene using the mouse and the scene can get many thousand objects to render.
Mitglieder in diesem Forum: 0 Mitglieder und 2 Gäste
Du darfst keine neuen Themen in diesem Forum erstellen. Du darfst keine Antworten zu Themen in diesem Forum erstellen. Du darfst deine Beiträge in diesem Forum nicht ändern. Du darfst deine Beiträge in diesem Forum nicht löschen. Du darfst keine Dateianhänge in diesem Forum erstellen.