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 (1 place).
'Primary Code:
'During initialization, make sure that the control handle is used
Control Handle hdlg, %ID_Graphic To hGraphic
hDC = GetDC(hLabel)
'Also, during %WM_Size, be sure to set the control size, and use the
'same w/h for setting the OpenGL viewpoint (passed as arguments to ResizeScene
Case %WM_Size
Control Set Size hDlg, %ID_Label, Lo(Word, CB.lParam)-20, Hi(Word, CB.lParam)-20
ResizeScene Lo(Word, CB.lParam)-20, Hi(Word, CB.lParam)-20
'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_Label = 1002
Global hDlg, hDC, hRC, hLabel As DWord
Global scalefactor As Single
Function PBMain() As Long
Dialog New Pixels, 0, "OpenGL Example",,, 320, 240,%WS_OverlappedWindow To hDlg
Control Add Label, hdlg, %ID_Label,"",10,10,100,100, %WS_Child Or %WS_Visible Or %SS_Sunken Or %SS_Notify
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 Set Size hDlg, %ID_Label, Lo(Word, CB.lParam)-20, Hi(Word, CB.lParam)-20
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_Label 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_Label To hLabel
hDC = GetDC(hLabel)
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_00585
'Date: 03-10-2012
http://www.garybeene.com/sw/gbsnippets.htm