use Up/Down arrow keys to zoom +/- . Esc to exit
more ideas or optimizations will be great ..
the example used is the "OpenGLGadget.pb" in "PureBasic\Examples\Sources\"
Code: Select all
;
; OpenGL Gadget demonstration
;
; (c) Fantaisie Software
;
; Axis explainations:
;
; +
; y
;
; |
; |
; + |
; x ---------\
; \
; \
; \
; z+
;
; So a rotate on the y axis will take the y axis as center. With OpenGL, we can specify
; positive And negative value. Positive values are always in the same sens as the axis
; (like described on the schmatic, with '+' signs)
;
Global RollAxisX.f
Global RollAxisY.f
Global RollAxisZ.f
Global RotateSpeedX.f = 1.0
Global RotateSpeedY.f
Global RotateSpeedZ.f = 1.0
Global ZoomFactor.f = 1.0 ; Distance of the camera. Negative value = zoom back
Procedure DrawCube(Gadget)
SetGadgetAttribute(Gadget, #PB_OpenGL_SetContext, #True)
glPushMatrix_() ; Save the original Matrix coordinates
glMatrixMode_(#GL_MODELVIEW)
glTranslatef_(0, 0, ZoomFactor) ; move it forward a bit
glRotatef_ (RollAxisX, 1.0, 0, 0) ; rotate around X axis
glRotatef_ (RollAxisY, 0, 1.0, 0) ; rotate around Y axis
glRotatef_ (RollAxisZ, 0, 0, 1.0) ; rotate around Z axis
RollAxisX + RotateSpeedX
RollAxisY + RotateSpeedY
RollAxisZ + RotateSpeedZ
; clear framebuffer And depth-buffer
glClear_ (#GL_COLOR_BUFFER_BIT | #GL_DEPTH_BUFFER_BIT)
; draw the faces of a cube
; draw colored faces
glDisable_(#GL_LIGHTING)
glBegin_ (#GL_QUADS)
; Build a face, composed of 4 vertex !
; glBegin() specify how the vertexes are considered. Here a group of
; 4 vertexes (GL_QUADS) form a rectangular surface.
; Now, the color stuff: It's r,v,b but with float values which
; can go from 0.0 To 1.0 (0 is .. zero And 1.0 is full intensity)
glNormal3f_ (0,0,1.0)
glColor3f_ (0,0,1.0)
glVertex3f_ (0.5,0.5,0.5)
glColor3f_ (0,1.0,1.0)
glVertex3f_ (-0.5,0.5,0.5)
glColor3f_ (1.0,1.0,1.0)
glVertex3f_ (-0.5,-0.5,0.5)
glColor3f_ (0,0,0)
glVertex3f_ (0.5,-0.5,0.5)
; The other face is the same than the previous one
; except the colour which is nice blue To white gradiant
glNormal3f_ (0,0,-1.0)
glColor3f_ (0,0,1.0)
glVertex3f_ (-0.5,-0.5,-0.5)
glColor3f_ (0,0,1.0)
glVertex3f_ (-0.5,0.5,-0.5)
glColor3f_ (1.0,1.0,1.0)
glVertex3f_ (0.5,0.5,-0.5)
glColor3f_ (1.0,1.0,1.0)
glVertex3f_ (0.5,-0.5,-0.5)
glEnd_()
; draw shaded faces
glEnable_(#GL_LIGHTING)
glEnable_(#GL_LIGHT0)
glBegin_ (#GL_QUADS)
glNormal3f_ ( 0, 1.0, 0)
glVertex3f_ ( 0.5, 0.5, 0.5)
glVertex3f_ ( 0.5, 0.5,-0.5)
glVertex3f_ (-0.5, 0.5,-0.5)
glVertex3f_ (-0.5, 0.5, 0.5)
glNormal3f_ (0,-1.0,0)
glVertex3f_ (-0.5,-0.5,-0.5)
glVertex3f_ (0.5,-0.5,-0.5)
glVertex3f_ (0.5,-0.5,0.5)
glVertex3f_ (-0.5,-0.5,0.5)
glNormal3f_ (1.0,0,0)
glVertex3f_ (0.5,0.5,0.5)
glVertex3f_ (0.5,-0.5,0.5)
glVertex3f_ (0.5,-0.5,-0.5)
glVertex3f_ (0.5,0.5,-0.5)
glNormal3f_ (-1.0, 0, 0)
glVertex3f_ (-0.5,-0.5,-0.5)
glVertex3f_ (-0.5,-0.5, 0.5)
glVertex3f_ (-0.5, 0.5, 0.5)
glVertex3f_ (-0.5, 0.5,-0.5)
glEnd_()
glPopMatrix_()
glFinish_()
SetGadgetAttribute(Gadget, #PB_OpenGL_FlipBuffers, #True)
EndProcedure
Procedure SetupGL()
glMatrixMode_(#GL_PROJECTION)
gluPerspective_(30.0, 200/200, 1.0, 50)
; position viewer
glMatrixMode_(#GL_MODELVIEW)
glTranslatef_(0, 0, -5.0)
glEnable_(#GL_DEPTH_TEST) ; Enabled, it slowdown a lot the rendering. It's to be sure than the
; rendered objects are inside the z-buffer.
glEnable_(#GL_CULL_FACE) ; This will enhance the rendering speed as all the back face will be
; ignored. This works only with CLOSED objects like a cube... Singles
; planes surfaces will be visibles only on one side.
glShadeModel_(#GL_SMOOTH)
EndProcedure
Procedure HandleError (Result, Text$)
If Result = 0
MessageRequester("Error", Text$, 0)
End
EndIf
EndProcedure
OpenWindow(0, 0, 0, 530, 320, "OpenGL Gadget.. Up/Down arrow keys to zoom+/-....Esc to exit", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
OpenGLGadget(0, 10, 10, 200, 200, #PB_OpenGL_Keyboard )
SetupGL()
OpenGLGadget(1, 220, 10, 300, 300)
SetupGL()
AddWindowTimer(0, 1, 16) ; about 60 fps
SetActiveGadget(0)
Repeat
Event = WaitWindowEvent()
Select Event
Case #PB_Event_Timer
If EventTimer() = 1
DrawCube(0)
DrawCube(1)
EndIf
EndSelect
If Event = #PB_Event_Gadget And EventGadget() = 0
If EventType() = #PB_EventType_KeyDown
key = GetGadgetAttribute(0,#PB_OpenGL_Key )
;If key = 38 ; Up arrow key
If key = #PB_Shortcut_Up
ZoomFactor.f + 0.1
;ElseIf key = 40 ; Down arrow key
ElseIf key = #PB_Shortcut_Down ; Down arrow key
ZoomFactor.f - 0.1
ElseIf key = #PB_Shortcut_Escape ; Esc key to exit
quit = 1
EndIf
EndIf
EndIf
Until Event = #PB_Event_CloseWindow Or quit = 1
