Date: 02-16-2022
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created by gbSnippets
'Most of the OpenGL snippets use the dialog for display, but you can just
'as easily use a control. This example shows how to use a graphic control
'as the OpenGL canvas.
'Compiler Comments:
'This code is written to compile in PBWin10. To compile in PBWin9, split pt
'into pt.x and pt.y as arguments wherever the ChildWindowFromPoint() API is used.
'Primary Code:
'During initialization, make sure that the control handle is used
Control Handle hdlg, %ID_Graphic To hGraphic
hDC = GetDC(hGraphic)
'Also, during %WM_Size, you have kill the graphic control and add it again since it
'cannot be resized. You also have to get a new rendering context, reinitialize
'the scene and resize the OpenGL viewport each time the dialog is resized.
Case %WM_Size : Control Kill hDlg, %ID_Graphic
Control Add Graphic, hDlg, %ID_Graphic,"",10,10,Lo(Word,CB.lParam)-20,Hi(Word,CB.lParam)-20, %WS_Child Or %WS_Visible Or %SS_Sunken Or %SS_Notify
Graphic Attach hDlg, %ID_Graphic
GetRenderContext : InitializeScene
ResizeScene Lo(Word, CB.lParam)-20, Hi(Word, CB.lParam)-20
DrawScene 0,0,0 'redraw with no rotation
'And finally, you need to ensure that the mouse action is over the control before
'entering manual drag mode.
Case %WM_SetCursor
GetCursorPos pt 'p.x and p.y are in screen coordinates
ScreenToClient hDlg, pt 'p.x and p.y are now dialog client coordinates
If GetDlgCtrlID(ChildWindowFromPoint( hDlg, pt )) <> %ID_Graphic Then Exit Function
'Compilable Example: (Jose Includes)
#Compiler PBWin 10
#Compile EXE
#Dim All
%Unicode=1
#Include "win32api.inc"
#Include "gl.inc"
#Include "glu.inc"
%ID_Timer = 1000 : %ID_Graphic = 1002
Global hDlg, hDC, hRC, hGraphic As DWord
Global scalefactor As Single
Function PBMain() As Long
Dialog New Pixels, 0, "OpenGL Example",,, 320, 240,%WS_OverlappedWindow To hDlg
Dialog Show Modal hdlg Call dlgproc
End Function
CallBack Function dlgproc()
Local pt As Point
Local XDelta, YDelta as Single
Static SpinInWork,XLast,YLast As Long
Select Case CB.Msg
Case %WM_InitDialog : GetRenderContext
InitializeScene
SetTimer(hDlg, %ID_Timer, 50, %NULL)
ScaleFactor = 1
Case %WM_Timer : DrawScene 1,1,0 'redraw with rotation on all 3 axes
Case %WM_Paint : DrawScene 0,0,0 'redraw with no rotation
Case %WM_Size : Control Kill hDlg, %ID_Graphic
Control Add Graphic, hDlg, %ID_Graphic,"",10,10,Lo(Word,CB.lParam)-20,Hi(Word,CB.lParam)-20, %WS_Child Or %WS_Visible Or %SS_Sunken Or %SS_Notify
Graphic Attach hDlg, %ID_Graphic
GetRenderContext : InitializeScene
ResizeScene Lo(Word, CB.lParam)-20, Hi(Word, CB.lParam)-20
DrawScene 0,0,0 'redraw with no rotation
Case %WM_Close : wglmakecurrent %null, %null 'unselect rendering context
wgldeletecontext hRC 'delete the rendering context
releasedc hDlg, hDC 'release device context
Case %WM_MouseWheel
Select Case Hi(Integer,CB.wParam)
Case > 0 : ScaleFactor = ScaleFactor + 0.1 : DrawScene 0,0,0
Case < 0 : ScaleFactor = ScaleFactor - 0.1 : DrawScene 0,0,0
End Select
Case %WM_SetCursor
GetCursorPos pt 'p.x and p.y are in screen coordinates
ScreenToClient hDlg, pt 'p.x and p.y are now dialog client coordinates
If GetDlgCtrlID(ChildWindowFromPoint( hDlg, pt )) <> %ID_Graphic Then Exit Function
Select Case Hi(Word, CB.lParam)
Case %WM_LButtonDown
GetCursorPos pt 'pt has xy screen coordinates
ScreenToClient hDlg, pt 'pt now has dialog client coordinates
If pt.y < 0 Then Exit Select
KillTimer CB.Hndl, %ID_Timer
SpinInWork = 1
XLast = Pt.x
YLast = Pt.y
Case %WM_MouseMove
If SpinInWork Then
GetCursorPos pt 'pt has xy screen coordinates
ScreenToClient hDlg, pt 'pt now has dialog client coordinates
If pt.y < 0 Then Exit Select
XDelta = XLast - Pt.x
YDelta = YLast - Pt.y
DrawScene -YDelta, -XDelta, 0
XLast = pt.x
YLast = pt.y
End If
Case %WM_LButtonUp
SetTimer(hDlg, %ID_Timer, 50, %NULL)
SpinInWork = 0
End Select
End Select
End Function
Sub GetRenderContext
Local pfd As PIXELFORMATDESCRIPTOR 'pixel format properties for device context
pfd.nSize = SizeOf(PIXELFORMATDESCRIPTOR)
pfd.nVersion = 1
pfd.dwFlags = %pfd_draw_to_window Or %pfd_support_opengl Or %pfd_doublebuffer
pfd.dwlayermask = %pfd_main_plane
pfd.iPixelType = %pfd_type_rgba
pfd.ccolorbits = 24
pfd.cdepthbits = 24
Control Handle hdlg, %ID_Graphic To hGraphic
hDC = GetDC(hGraphic)
SetPixelFormat(hDC, ChoosePixelFormat(hDC, pfd), pfd) 'set properties of device context
hRC = wglCreateContext (hDC) 'get rendering context
wglMakeCurrent hDC, hRC 'make the RC current
End Sub
Sub InitializeScene
glClearColor 0,0,0,0 'sets color to be used with glClear
glClearDepth 1 'sets zvalue to be used with glClear
glEnable %gl_depth_test 'enable depth testing
glHint %gl_perspective_correction_hint, %gl_nicest 'best quality rendering
BuildDisplayList 1
End Sub
Sub ResizeScene (w As Long, h As Long)
glViewport 0, 0, w, h 'resize viewport to match window size
glMatrixMode %gl_projection 'select the projection matrix
glLoadIdentity 'reset the projection matrix
gluPerspective 45, w/h, 0.1, 100 'set frustum using viewport aspect ratio
glMatrixMode %gl_modelview 'select the modelview matrix
End Sub
Sub DrawScene (dx As Single, dy As Single, dz As Single)
Static anglex, angley, anglez As Single
glClear %gl_color_buffer_bit Or %gl_depth_buffer_bit 'clear buffers
glLoadIdentity 'clear the modelview matrix
gluLookAt 0,0,6,0,0,0,0,1,0
glScalef scalefactor, scalefactor, scalefactor
anglex = anglex + dx : glRotatef anglex, 1,0,0
angley = angley + dy : glRotatef angley, 0,1,0
anglez = anglez + dz : glRotatef anglez, 0,0,1
glCallList 1
SwapBuffers hDC 'display the buffer (image)
End Sub
Sub BuildDisplayList(ListNumber As Long)
glNewList ListNumber, %gl_compile
glBegin %GL_QUADS
glColor3f 0.0, 1.0, 0.0 ' Set the color to green
glVertex3f 1.0, 1.0, -1.0 ' Top right of the quad (Top)
glVertex3f -1.0, 1.0, -1.0 ' Top left of the quad (Top)
glVertex3f -1.0, 1.0, 1.0 ' Bottom left of the quad (Top)
glVertex3f 1.0, 1.0, 1.0 ' Bottom right of the quad (Top)
glColor3f 1.0, 0.5, 0.0 ' Set the color to orange
glVertex3f 1.0, -1.0, 1.0 ' Top right of the quad (Bottom)
glVertex3f -1.0, -1.0, 1.0 ' Top left of the quad (Bottom)
glVertex3f -1.0, -1.0, -1.0 ' Bottom left of the quad (Bottom)
glVertex3f 1.0, -1.0, -1.0 ' Bottom right of the quad (Bottom)
glColor3f 1.0, 0.0, 0.0 ' Set the color to red
glVertex3f 1.0, 1.0, 1.0 ' Top right of the quad (Front)
glVertex3f -1.0, 1.0, 1.0 ' Top left of the quad (Front)
glVertex3f -1.0, -1.0, 1.0 ' Bottom left of the quad (Front)
glVertex3f 1.0, -1.0, 1.0 ' Bottom right of the quad (Front)
glColor3f 1.0, 1.0, 0.0 ' Set the color to yellow
glVertex3f 1.0, -1.0, -1.0 ' Top right of the quad (Back)
glVertex3f -1.0, -1.0, -1.0 ' Top left of the quad (Back)
glVertex3f -1.0, 1.0, -1.0 ' Bottom left of the quad (Back)
glVertex3f 1.0, 1.0, -1.0 ' Bottom right of the quad (Back)
glColor3f 0.0, 0.0, 1.0 ' Set the color to blue
glVertex3f -1.0, 1.0, 1.0 ' Top right of the quad (Left)
glVertex3f -1.0, 1.0, -1.0 ' Top left of the quad (Left)
glVertex3f -1.0, -1.0, -1.0 ' Bottom left of the quad (Left)
glVertex3f -1.0, -1.0, 1.0 ' Bottom right of the quad (Left)
glColor3f 1.0, 0.0, 1.0 ' Set the color to violet
glVertex3f 1.0, 1.0, -1.0 ' Top right of the quad (Right)
glVertex3f 1.0, 1.0, 1.0 ' Top left of the quad (Right)
glVertex3f 1.0, -1.0, 1.0 ' Bottom left of the quad (Right)
glVertex3f 1.0, -1.0, -1.0 ' Bottom right of the quad (Right)
glEnd
glEndList
End Sub
'gbs_00584
'Date: 03-10-2012
http://www.garybeene.com/sw/gbsnippets.htm