In fact there are quite some documentation, however currently only in german. However, let us try a small example.
To get sure you have everything you need: http://files.delphigl.com/Download/dglsdk_2005_2.exe This is our DGLSDK Installer. It installs several common headers you might find interesting (OpenGL Header from us, SDL from the JEDIs, several Texture loader). It also add these headers to the search path of delphi.
http://www.delphigl.com/download.php?cat=1 There you find our templates for a really basic opengl init. You will find especially the VCL example usefull:
http://www.delphigl.com/do_download.php?f=8
Search there the method ApplicationEventsIdle and replace
Code: // In die Projektionsmatrix wechseln glMatrixMode(GL_PROJECTION); // Identit�smatrix laden glLoadIdentity; // Viewport an Clientareal des Fensters anpassen glViewPort(0, 0, ClientWidth, ClientHeight); // Perspective, FOV und Tiefenreichweite setzen gluPerspective(60, ClientWidth/ClientHeight, 1, 128); // In die Modelansichtsmatrix wechseln glMatrixMode(GL_MODELVIEW); // Identit�smatrix laden glLoadIdentity; // Farb- und Tiefenpuffer l�chen glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT); ShowText; // Hinteren Puffer nach vorne bringen SwapBuffers(DC); // Windows denken lassen, das wir noch nicht fertig w�en Done := False; // Nummer des gezeichneten Frames erh�en inc(Frames); // FPS aktualisieren if GetTickCount - StartTick >= 500 then begin FPS := Frames/(GetTickCount-StartTick)*1000; Frames := 0; StartTick := GetTickCount end;
Code: glMatrixMode(GL_PROJECTION); glLoadIdentity; glOrtho(0,800,0,600, 0,128); glMatrixMode(GL_MODELVIEW); glClearColor(0.0,0.0,0.0,1); glClear( GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT ); glLineWidth(2); glLoadIdentity; glDisable(GL_TEXTURE_2D); glBegin(GL_LINE_STRIP); glColor3f(1,0,0); glVertex2f(0,0); glColor3f(0,1,0); glVertex2f(100,100); glColor3f(0,0,1); glVertex2f(200,100); glEnd; // Hinteren Puffer nach vorne bringen SwapBuffers(DC); // Windows denken lassen, das wir noch nicht fertig w�en Done := False; // Nummer des gezeichneten Frames erh�en inc(Frames); // FPS aktualisieren if GetTickCount - StartTick >= 500 then begin FPS := Frames/(GetTickCount-StartTick)*1000; Frames := 0; StartTick := GetTickCount end;
You might to change the arguments of glOrtho. I am not using VCL, but SDL under Linux with a fixed windows size of 800/600. So you might want to set in the size of the forum instead. You should then be able to see a colored line from 0/0 (left bottom) to 100/100 then straight ahead to 200/100. This way you easily could draw lines with opengl in "2D mode". Using GL_QUAD allows to draw filled rectangles even with texture for drawing "images". GL_POLYGON might be intersting if you have to fill out some unconvential area. Just circles are not that easy, cause they are not a shape a 3D card really likes. However, if you a drawing most times lines, triagles or quads, you can greatly benefit from your 3D card. Also notice our (old) template for using two render context: http://www.delphigl.com/do_download.php?f=3333 You might find it usefull, if you need two viewports on your frame. Also notice that there is shown how you could use a panel as opengl viewport instead of the whole form. Hope this helps a little bit.
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No, just kidding. In fact the real problem in using opengl is to math for calculating matrices. If you are just using a fixed position from above to display some data on the screen, it might be even easier than using simple 2d. But if you move into the scene, able to rotate arround all three axis with some blending etc. it will get more and more complicate. However, I think you should give OpenGL a try and will find it quite comfortable to realize a vector program with it.