NeHe Lesson 06: Texture Mapping

[José Roca]

 
This example illustrates how to map a bitmap image onto the six sides of a cube.

It is an adaptation of Nehe Lesson 06: http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=06

Code Select Expand


' SED_PBWIN - Use the PBWIN compiler
#COMPILE EXE
#DIM ALL
#INCLUDE "GLU.INC"
#INCLUDE "GDIPLUS.INC"
#INCLUDE "GDIPUTILS.INC"

$WindowCaption = "NeHe Lesson 06"

%GL_WINDOWWIDTH  = 640         ' Window width
%GL_WINDOWHEIGHT = 480         ' Window height
%GL_BITSPERPEL   = 16          ' Color resolution in bits per pixel
%GL_DEPTHBITS    = 16          ' Depth of the depth (z-axis) buffer

GLOBAL hDC AS LONG             ' Device context handle
GLOBAL TextureHandle AS DWORD
GLOBAL xrot AS SINGLE
GLOBAL yrot AS SINGLE
GLOBAL zrot AS SINGLE

' =======================================================================================
' All the setup goes here
' =======================================================================================
SUB SetupScene (BYVAL hwnd AS DWORD, BYVAL nWidth AS LONG, BYVAL nHeight AS LONG)

   LOCAL hr AS LONG
   LOCAL strTextureData AS STRING
   LOCAL TextureWidth, TextureHeight AS LONG

   ' Specify clear values for the color buffers
   glClearColor 0.0!, 0.0!, 0.0!, 0.0!
   ' Specify the clear value for the depth buffer
   glClearDepth 1.0!
   ' Specify the value used for depth-buffer comparisons
   glDepthFunc %GL_LESS
   ' Enable depth comparisons and update the depth buffer
   glEnable %GL_DEPTH_TEST
   ' Select smooth shading
   glShadeModel %GL_SMOOTH

   ' Load bitmap texture from disk
   hr = GdiPlusLoadTexture("NeHe.bmp", TextureWidth, TextureHeight, strTextureData, %TRUE)

   ' Assign an OpenGL handle to this texture
   glGenTextures 1, TextureHandle

   ' Activate our newly created texture
   glEnable %GL_TEXTURE_2D
   glTexEnvf %GL_TEXTURE_ENV, %GL_TEXTURE_ENV_MODE, %GL_MODULATE
   glBindTexture %GL_TEXTURE_2D, TextureHandle

   ' Create the texture
   glTexParameteri %GL_TEXTURE_2D, %GL_TEXTURE_MAG_FILTER, %GL_LINEAR
   glTexParameteri %GL_TEXTURE_2D, %GL_TEXTURE_MIN_FILTER, %GL_LINEAR
   glTexImage2D %GL_TEXTURE_2D, 0, %GL_RGBA, TextureWidth, TextureHeight, 0, _
                %GL_RGBA, %GL_UNSIGNED_BYTE, BYVAL STRPTR(strTextureData)

END SUB
' =======================================================================================

' =======================================================================================
' Resize the scene
' =======================================================================================
SUB ResizeScene (BYVAL hwnd AS DWORD, BYVAL nWidth AS LONG, BYVAL nHeight AS LONG)

   ' Prevent divide by zero making height equal one
   IF nHeight = 0 THEN nHeight = 1
   ' Reset the current viewport
   glViewport 0, 0, nWidth, nHeight
   ' Select the projection matrix
   glMatrixMode %GL_PROJECTION
   ' Reset the projection matrix
   glLoadIdentity
   ' Calculate the aspect ratio of the window
   gluPerspective 45.0!, nWidth / nHeight, 0.1!, 100.0!
   ' Select the model view matrix
   glMatrixMode %GL_MODELVIEW
   ' Reset the model view matrix
   glLoadIdentity

END SUB
' =======================================================================================

' =======================================================================================
' Draw the scene
' =======================================================================================
SUB DrawScene (BYVAL hwnd AS DWORD, BYVAL nWidth AS LONG, BYVAL nHeight AS LONG)

   ' Clear the screen buffer
   glClear %GL_COLOR_BUFFER_BIT OR %GL_DEPTH_BUFFER_BIT
   ' Reset the view
   glLoadIdentity

   glTranslatef 0.0!, 0.0!, -5.0!
   glRotatef xrot, 1.0!, 0.0!, 0.0!           ' Rotate on the x axis
   glRotatef yrot, 0.0!, 1.0!, 0.0!           ' Rotate on the y axis
   glRotatef zrot, 0.0!, 0.0!, 1.0!           ' Rotate on the z axis
   glBindTexture %GL_TEXTURE_2D, TextureHandle

   glBegin %GL_QUADS
      ' Front Face
      glTexCoord2f 0.0!, 0.0! : glVertex3f -1.0!, -1.0!,  1.0!      ' bottom left of the texture and quad
      glTexCoord2f 1.0!, 0.0! : glVertex3f  1.0!, -1.0!,  1.0!      ' bottom right of the texture and quad
      glTexCoord2f 1.0!, 1.0! : glVertex3f  1.0!,  1.0!,  1.0!      ' top right of the texture and quad
      glTexCoord2f 0.0!, 1.0! : glVertex3f -1.0!,  1.0!,  1.0!      ' top left of the texture and quad
      ' Back Face
      glTexCoord2f 1.0!, 0.0! : glVertex3f -1.0!, -1.0!, -1.0!      ' bottom right of the texture and quad
      glTexCoord2f 1.0!, 1.0! : glVertex3f -1.0!,  1.0!, -1.0!      ' top right of the texture and quad
      glTexCoord2f 0.0!, 1.0! : glVertex3f  1.0!,  1.0!, -1.0!      ' top left of the texture and quad
      glTexCoord2f 0.0!, 0.0! : glVertex3f  1.0!, -1.0!, -1.0!      ' bottom left of the texture and quad
      ' Top Face
      glTexCoord2f 0.0!, 1.0! : glVertex3f -1.0!,  1.0!, -1.0!      ' top left of the texture and quad
      glTexCoord2f 0.0!, 0.0! : glVertex3f -1.0!,  1.0!,  1.0!      ' bottom left of the texture and quad
      glTexCoord2f 1.0!, 0.0! : glVertex3f  1.0!,  1.0!,  1.0!      ' bottom right of the texture and quad
      glTexCoord2f 1.0!, 1.0! : glVertex3f  1.0!,  1.0!, -1.0!      ' top right of the texture and quad
      ' Bottom Face
      glTexCoord2f 1.0!, 1.0! : glVertex3f -1.0!, -1.0!, -1.0!      ' top right of the texture and quad
      glTexCoord2f 0.0!, 1.0! : glVertex3f  1.0!, -1.0!, -1.0!      ' top left of the texture and quad
      glTexCoord2f 0.0!, 0.0! : glVertex3f  1.0!, -1.0!,  1.0!      ' bottom left of the texture and quad
      glTexCoord2f 1.0!, 0.0! : glVertex3f -1.0!, -1.0!,  1.0!      ' bottom right of the texture and quad
      ' Right face
      glTexCoord2f 1.0!, 0.0! : glVertex3f  1.0!, -1.0!, -1.0!      ' bottom right of the texture and quad
      glTexCoord2f 1.0!, 1.0! : glVertex3f  1.0!,  1.0!, -1.0!      ' top right of the texture and quad
      glTexCoord2f 0.0!, 1.0! : glVertex3f  1.0!,  1.0!,  1.0!      ' top left of the texture and quad
      glTexCoord2f 0.0!, 0.0! : glVertex3f  1.0!, -1.0!,  1.0!      ' bottom left of the texture and quad
      ' Left Face
      glTexCoord2f 0.0!, 0.0! : glVertex3f -1.0!, -1.0!, -1.0!      ' bottom left of the texture and quad
      glTexCoord2f 1.0!, 0.0! : glVertex3f -1.0!, -1.0!,  1.0!      ' bottom right of the texture and quad
      glTexCoord2f 1.0!, 1.0! : glVertex3f -1.0!,  1.0!,  1.0!      ' top right of the texture and quad
      glTexCoord2f 0.0!, 1.0! : glVertex3f -1.0!,  1.0!, -1.0!      ' top left of the texture and quad
   glEnd

   xrot = xrot + 0.3!                         ' x axis rotation
   yrot = yrot + 0.2!                         ' y axis rotation
   zrot = zrot + 0.4!                         ' z axis rotation

END SUB
' =======================================================================================

' =======================================================================================
' Cleanup
' =======================================================================================
SUB Cleanup (BYVAL hwnd AS DWORD)

   ' Delete the texture
   IF TextureHandle THEN glDeleteTextures(1, TextureHandle)

END SUB
' =======================================================================================

' =======================================================================================
' Processes keystrokes
' Parameters:
' * hwnd = Window hande
' * vKeyCode = Virtual key code
' * bKeyDown = %TRUE if key is pressed; %FALSE if it is released
' =======================================================================================
SUB ProcessKeystrokes (BYVAL hwnd AS DWORD, BYVAL vKeyCode AS LONG, BYVAL bKeyDown AS LONG)

   SELECT CASE AS LONG vKeyCode

      CASE %VK_ESCAPE
         ' Quit if Esc key pressed
         SendMessage hwnd, %WM_CLOSE, 0, 0

   END SELECT

END SUB
' =======================================================================================

' =======================================================================================
' Main
' =======================================================================================
FUNCTION WINMAIN (BYVAL hInstance AS DWORD, BYVAL hPrevInstance AS DWORD, BYVAL lpszCmdLine AS ASCIIZ PTR, BYVAL nCmdShow AS LONG) AS LONG

   LOCAL  hwnd        AS DWORD
   LOCAL  wcex        AS WNDCLASSEX
   LOCAL  szClassName AS ASCIIZ * 256
   LOCAL  szCaption   AS ASCIIZ * 256
   LOCAL  msg         AS tagMSG
   LOCAL  rc          AS RECT
   LOCAL  bDone       AS LONG
   LOCAL  nLeft       AS LONG
   LOCAL  nTop        AS LONG
   LOCAL  nWidth      AS LONG
   LOCAL  nHeight     AS LONG
   LOCAL  dwStyle     AS DWORD
   LOCAL  dwStyleEx   AS DWORD
   STATIC vKeyCode    AS LONG
   STATIC bKeyDown    AS LONG
   LOCAL  t           AS DOUBLE
   LOCAL  t0          AS DOUBLE
   LOCAL  fps         AS DOUBLE
   LOCAL  nFrames     AS LONG
   LOCAL  dm          AS DEVMODE
   LOCAL  bFullScreen AS LONG
   LOCAL  lResult     AS LONG

   ' Register the window class
   szClassName        = "PBOPENGL"
   wcex.cbSize        = SIZEOF(wcex)
   wcex.style         = %CS_HREDRAW OR %CS_VREDRAW OR %CS_OWNDC
   wcex.lpfnWndProc   = CODEPTR(WndProc)
   wcex.cbClsExtra    = 0
   wcex.cbWndExtra    = 0
   wcex.hInstance     = hInstance
   wcex.hCursor       = LoadCursor (%NULL, BYVAL %IDC_ARROW)
   wcex.hbrBackground = %NULL
   wcex.lpszMenuName  = %NULL
   wcex.lpszClassName = VARPTR(szClassName)
   wcex.hIcon         = LoadIcon (%NULL, BYVAL %IDI_APPLICATION) ' Sample, if resource icon: LoadIcon(hInst, "APPICON")
   wcex.hIconSm       = LoadIcon (%NULL, BYVAL %IDI_APPLICATION) ' Remember to set small icon too..
   RegisterClassEx wcex

' Ask the user which screen mode he prefers
lResult = MessageBox(%NULL, "Would you like to run in fullscreen mode?", _
             "Start fullScreen?", %MB_YESNOCANCEL OR %MB_ICONQUESTION)
   SELECT CASE lResult
      CASE %IDCANCEL : EXIT FUNCTION
      CASE %IDYES    : bFullScreen = %TRUE
      CASE %IDNO     : bFullScreen = %FALSE
   END SELECT

   ' Window size
   nWidth  = %GL_WINDOWWIDTH
   nHeight = %GL_WINDOWHEIGHT

   IF bFullScreen THEN
      ' Change display settings
      dm.dmSize       = SIZEOF(dm)
      dm.dmPelsWidth  = nWidth
      dm.dmPelsHeight = nHeight
      dm.dmBitsPerPel = %GL_BITSPERPEL
      dm.dmFields     = %DM_BITSPERPEL OR %DM_PELSWIDTH OR %DM_PELSHEIGHT
      IF ChangeDisplaySettings(dm, %CDS_FULLSCREEN) = 0 THEN ShowCursor %FALSE
   END IF

   ' Window caption
   szCaption = $WindowCaption

   ' Window styles
   IF ISFALSE bFullScreen THEN
      dwStyle = %WS_OVERLAPPEDWINDOW
      dwStyleEx = %WS_EX_APPWINDOW OR %WS_EX_WINDOWEDGE
   ELSE
      dwStyle = %WS_POPUP
      dwStyleEx = %WS_EX_APPWINDOW
   END IF

   ' Create the window
   hwnd = CreateWindowEx( _
            dwStyleEx, _                      ' extended styles
            szClassName, _                    ' window class name
            szCaption, _                      ' window caption
            dwStyle, _                        ' window style
            nLeft, _                          ' initial x position
            nTop, _                           ' initial y position
            nWidth, _                         ' initial x size
            nHeight, _                        ' initial y size
            %NULL, _                          ' parent window handle
            0, _                              ' window menu handle
            hInstance, _                      ' program instance handle
            BYVAL %NULL)                      ' creation parameters

   ' Retrieve the coordinates of the window's client area
   GetClientRect hwnd, rc
   ' Initialize the new OpenGl window
   SetupScene hwnd, rc.nRight - rc.nLeft, rc.nBottom - rc.nTop

   ' Show the window
   ShowWindow hwnd, nCmdShow
   UpdateWindow hwnd

   DO UNTIL bDone

      ' Windows message pump
      DO WHILE PeekMessage(msg, %NULL, 0, 0, %PM_REMOVE)
         IF msg.message = %WM_QUIT THEN
            bDone = %TRUE
         ELSE
            IF msg.message = %WM_KEYDOWN THEN
               vKeyCode = msg.wParam
               bKeyDown = %TRUE
            ELSEIF msg.message = %WM_KEYUP THEN
               vKeyCode = msg.wParam
               bKeyDown = %FALSE
            END IF
            TranslateMessage msg
            DispatchMessage msg
         END IF
      LOOP

      IF ISFALSE bFullScreen THEN
         ' Get time and mouse position
         t = INT(TIMER)
         ' Calculate and display FPS (frames per second)
         IF t > t0 OR nFrames = 0 THEN
            fps = nFrames \ (t - t0)
            wsprintf szCaption, $WindowCaption & " (%i FPS)", BYVAL fps
            SetWindowText hwnd, szCaption
            t0 = t
            nFrames = 0
         END IF
         nFrames = nFrames + 1
      END IF

      ' Draw the scene
      DrawScene hwnd, nWidth, nHeight
      ' Exchange the front and back buffers
      SwapBuffers hDC

      ' Process the keystrokes
      IF vKeyCode THEN
         ProcessKeystrokes hwnd, vKeyCode, bKeyDown
         vKeyCode = 0
      END IF

   LOOP

   ' Retore defaults
   IF bFullScreen THEN
      ChangeDisplaySettings BYVAL %NULL, 0
      ShowCursor %TRUE
   END IF

   FUNCTION = msg.wParam

END FUNCTION
' =======================================================================================

' =======================================================================================
' Main window procedure
' =======================================================================================
FUNCTION WndProc (BYVAL hwnd AS DWORD, BYVAL wMsg AS DWORD, BYVAL wParam AS DWORD, BYVAL lParam AS LONG) AS LONG

   LOCAL  pf           AS LONG
   LOCAL  pfd          AS PIXELFORMATDESCRIPTOR
   STATIC hRC          AS LONG

   SELECT CASE wMsg

      CASE %WM_SYSCOMMAND

         ' Disable the Windows screensaver
         IF (wParam AND &HFFF0) = %SC_SCREENSAVE THEN EXIT FUNCTION

         ' Close the window
         IF (wParam AND &HFFF0) = %SC_CLOSE THEN
            SendMessage hwnd, %WM_CLOSE, 0, 0
            EXIT FUNCTION
         END IF

      CASE %WM_CREATE

         ' Retrieve the device context handle
         hDC = GetDC(hwnd)

         ' Fill the PIXELFORMATDESCRIPTOR structure
         pfd.nSize           = SIZEOF(PIXELFORMATDESCRIPTOR)   ' Size of the structure
         pfd.nVersion        = 1                               ' Version number
         pfd.dwFlags         = %PFD_DRAW_TO_WINDOW _           ' Format must support window
                               OR %PFD_SUPPORT_OPENGL _        ' Format must support OpenGL
                               OR %PFD_DOUBLEBUFFER            ' Format must support double buffering
         pfd.iPixelType      = %PFD_TYPE_RGBA                  ' Request an RGBA format
         pfd.cColorBits      = %GL_BITSPERPEL                  ' Number of color bitplanes in each color buffer
         pfd.cRedBits        = 0                               ' Number of red bitplanes in each RGBA color buffer.
         pfd.cRedShift       = 0                               ' Shift count for red bitplanes in each RGBA color buffer.
         pfd.cGreenBits      = 0                               ' Number of green bitplanes in each RGBA color buffer.
         pfd.cGreenShift     = 0                               ' Shift count for green bitplanes in each RGBA color buffer.
         pfd.cBlueBits       = 0                               ' Number of blue bitplanes in each RGBA color buffer.
         pfd.cBlueShift      = 0                               ' Shift count for blue bitplanes in each RGBA color buffer.
         pfd.cAlphaBits      = 0                               ' Number of alpha bitplanes in each RGBA color buffer
         pfd.cAlphaShift     = 0                               ' Shift count for alpha bitplanes in each RGBA color buffer.
         pfd.cAccumBits      = 0                               ' Total number of bitplanes in the accumulation buffer.
         pfd.cAccumRedBits   = 0                               ' Number of red bitplanes in the accumulation buffer.
         pfd.cAccumGreenBits = 0                               ' Number of gree bitplanes in the accumulation buffer.
         pfd.cAccumBlueBits  = 0                               ' Number of blue bitplanes in the accumulation buffer.
         pfd.cAccumAlphaBits = 0                               ' Number of alpha bitplanes in the accumulation buffer.
         pfd.cDepthBits      = %GL_DEPTHBITS                   ' Depth of the depth (z-axis) buffer.
         pfd.cStencilBits    = 0                               ' Depth of the stencil buffer.
         pfd.cAuxBuffers     = 0                               ' Number of auxiliary buffers.
         pfd.iLayerType      = %PFD_MAIN_PLANE                 ' Ignored. Earlier implementations of OpenGL used this member, but it is no longer used.
         pfd.bReserved       = 0                               ' Number of overlay and underlay planes.
         pfd.dwLayerMask     = 0                               ' Ignored. Earlier implementations of OpenGL used this member, but it is no longer used.
         pfd.dwVisibleMask   = 0                               ' Transparent color or index of an underlay plane.
         pfd.dwDamageMask    = 0                               ' Ignored. Earlier implementations of OpenGL used this member, but it is no longer used.

         ' Find a matching pixel format
         pf = ChoosePixelFormat(hDC, pfd)
         IF ISFALSE pf THEN
            MessageBox hwnd, "Can't find a suitable pixel format", _
                       "Error", %MB_OK OR %MB_ICONEXCLAMATION
            SendMessage hwnd, %WM_CLOSE, 0, 0
            EXIT FUNCTION
         END IF

         ' Set the pixel format
         IF ISFALSE SetPixelFormat(hDC, pf, pfd) THEN
            MessageBox hwnd, "Can't set the pixel format", _
                       "Error", %MB_OK OR %MB_ICONEXCLAMATION
            SendMessage hwnd, %WM_CLOSE, 0, 0
            EXIT FUNCTION
         END IF

         ' Create a new OpenGL rendering context
         hRC = wglCreateContext(hDC)
         IF ISFALSE hRC THEN
            MessageBox hwnd, "Can't create an OpenGL rendering context", _
                       "Error", %MB_OK OR %MB_ICONEXCLAMATION
            SendMessage hwnd, %WM_CLOSE, 0, 0
            EXIT FUNCTION
         END IF

         ' Make it current
         IF ISFALSE wglMakeCurrent(hDC,hRC) THEN
            MessageBox hwnd, "Can't activate the OpenGL rendering context", _
                       "Error", %MB_OK OR %MB_ICONEXCLAMATION
            SendMessage hwnd, %WM_CLOSE, 0, 0
            EXIT FUNCTION
         END IF

         EXIT FUNCTION

      CASE %WM_DESTROY
         ' Clear resources
         Cleanup hwnd
         ' Release the device and rendering contexts
         wglMakeCurrent hDC, 0
         ' Make the rendering context no longer current
         wglDeleteContext hRC
         ' Release the device context
         ReleaseDC hwnd, hDC
         ' Post an WM_QUIT message
         PostQuitMessage 0
         EXIT FUNCTION

      CASE %WM_SIZE
         ResizeScene hwnd, LO(WORD, lParam), HI(WORD, lParam)
         EXIT FUNCTION

   END SELECT

   ' Call the default window procedure to process unhandled messages
   FUNCTION = DefWindowProc(hwnd, wMsg, wParam, lParam)

END FUNCTION
' =======================================================================================


[José Roca]

 
This example illustrates how to map a bitmap image onto the six sides of a cube.

It is an adaptation of Nehe Lesson 06: http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=06

Code Select Expand


' SED_PBWIN - Use the PBWIN compiler
#COMPILE EXE
#DIM ALL
#INCLUDE "SDL.INC"
#INCLUDE "GLU.INC"
#INCLUDE "GDIPUTILS.INC"

$WindowCaption = "NeHe Lesson 6"

GLOBAL TextureHandle AS DWORD
GLOBAL xrot AS SINGLE
GLOBAL yrot AS SINGLE
GLOBAL zrot AS SINGLE

' =======================================================================================
' All the setup goes here
' =======================================================================================
SUB SetupScene ()

LOCAL hr AS LONG
LOCAL strTextureData AS STRING
LOCAL TextureWidth, TextureHeight AS LONG

' Specify clear values for the color buffers
glClearColor 0.0!, 0.0!, 0.0!, 0.0!
' Specify the clear value for the depth buffer
glClearDepth 1.0!
' Specify the value used for depth-buffer comparisons
glDepthFunc %GL_LESS
' Enable depth comparisons and update the depth buffer
glEnable %GL_DEPTH_TEST
' Select smooth shading
glShadeModel %GL_SMOOTH

' Load bitmap texture from disk
hr = GdiPlusLoadTexture("NeHe.bmp", TextureWidth, TextureHeight, strTextureData, %TRUE)

' Assign an OpenGL handle to this texture
glGenTextures 1, TextureHandle

' Activate our newly created texture
glEnable %GL_TEXTURE_2D
glTexEnvf %GL_TEXTURE_ENV, %GL_TEXTURE_ENV_MODE, %GL_MODULATE
glBindTexture %GL_TEXTURE_2D, TextureHandle

' Create the texture
glTexParameteri %GL_TEXTURE_2D, %GL_TEXTURE_MAG_FILTER, %GL_LINEAR
glTexParameteri %GL_TEXTURE_2D, %GL_TEXTURE_MIN_FILTER, %GL_LINEAR
glTexImage2D %GL_TEXTURE_2D, 0, %GL_RGBA, TextureWidth, TextureHeight, 0, _
%GL_RGBA, %GL_UNSIGNED_BYTE, BYVAL STRPTR(strTextureData)

END SUB
' =======================================================================================

' =======================================================================================
' Draw the scene
' =======================================================================================
SUB DrawScene (BYVAL nWidth AS LONG, BYVAL nHeight AS LONG)

' Clear the screen buffer
glClear %GL_COLOR_BUFFER_BIT OR %GL_DEPTH_BUFFER_BIT

' Select and setup the projection matrix
glMatrixMode %GL_PROJECTION
glLoadIdentity

' Prevent divide by zero making height equal one
IF nHeight = 0 THEN nHeight = 1

' Calculate the aspect ratio of the window
gluPerspective 45.0!, nWidth/nHeight, 1.0!, 100.0!

' Select and setup the modelview matrix
glMatrixMode %GL_MODELVIEW
glLoadIdentity

glTranslatef 0.0!, 0.0!, -5.0!
glRotatef xrot, 1.0!, 0.0!, 0.0!   ' Rotate on the x axis
glRotatef yrot, 0.0!, 1.0!, 0.0!   ' Rotate on the y axis
glRotatef zrot, 0.0!, 0.0!, 1.0!   ' Rotate on the z axis
glBindTexture %GL_TEXTURE_2D, TextureHandle

glBegin %GL_QUADS
' Front Face
glTexCoord2f 0.0!, 0.0! : glVertex3f -1.0!, -1.0!,  1.0! ' bottom left of the texture and quad
glTexCoord2f 1.0!, 0.0! : glVertex3f  1.0!, -1.0!,  1.0! ' bottom right of the texture and quad
glTexCoord2f 1.0!, 1.0! : glVertex3f  1.0!,  1.0!,  1.0! ' top right of the texture and quad
glTexCoord2f 0.0!, 1.0! : glVertex3f -1.0!,  1.0!,  1.0! ' top left of the texture and quad
' Back Face
glTexCoord2f 1.0!, 0.0! : glVertex3f -1.0!, -1.0!, -1.0! ' bottom right of the texture and quad
glTexCoord2f 1.0!, 1.0! : glVertex3f -1.0!,  1.0!, -1.0! ' top right of the texture and quad
glTexCoord2f 0.0!, 1.0! : glVertex3f  1.0!,  1.0!, -1.0! ' top left of the texture and quad
glTexCoord2f 0.0!, 0.0! : glVertex3f  1.0!, -1.0!, -1.0! ' bottom left of the texture and quad
' Top Face
glTexCoord2f 0.0!, 1.0! : glVertex3f -1.0!,  1.0!, -1.0! ' top left of the texture and quad
glTexCoord2f 0.0!, 0.0! : glVertex3f -1.0!,  1.0!,  1.0! ' bottom left of the texture and quad
glTexCoord2f 1.0!, 0.0! : glVertex3f  1.0!,  1.0!,  1.0! ' bottom right of the texture and quad
glTexCoord2f 1.0!, 1.0! : glVertex3f  1.0!,  1.0!, -1.0! ' top right of the texture and quad
' Bottom Face
glTexCoord2f 1.0!, 1.0! : glVertex3f -1.0!, -1.0!, -1.0! ' top right of the texture and quad
glTexCoord2f 0.0!, 1.0! : glVertex3f  1.0!, -1.0!, -1.0! ' top left of the texture and quad
glTexCoord2f 0.0!, 0.0! : glVertex3f  1.0!, -1.0!,  1.0! ' bottom left of the texture and quad
glTexCoord2f 1.0!, 0.0! : glVertex3f -1.0!, -1.0!,  1.0! ' bottom right of the texture and quad
' Right face
glTexCoord2f 1.0!, 0.0! : glVertex3f  1.0!, -1.0!, -1.0! ' bottom right of the texture and quad
glTexCoord2f 1.0!, 1.0! : glVertex3f  1.0!,  1.0!, -1.0! ' top right of the texture and quad
glTexCoord2f 0.0!, 1.0! : glVertex3f  1.0!,  1.0!,  1.0! ' top left of the texture and quad
glTexCoord2f 0.0!, 0.0! : glVertex3f  1.0!, -1.0!,  1.0! ' bottom left of the texture and quad
' Left Face
glTexCoord2f 0.0!, 0.0! : glVertex3f -1.0!, -1.0!, -1.0! ' bottom left of the texture and quad
glTexCoord2f 1.0!, 0.0! : glVertex3f -1.0!, -1.0!,  1.0! ' bottom right of the texture and quad
glTexCoord2f 1.0!, 1.0! : glVertex3f -1.0!,  1.0!,  1.0! ' top right of the texture and quad
glTexCoord2f 0.0!, 1.0! : glVertex3f -1.0!,  1.0!, -1.0! ' top left of the texture and quad
glEnd

xrot = xrot + 0.3! ' x axis rotation
yrot = yrot + 0.2! ' y axis rotation
zrot = zrot + 0.4! ' z axis rotation

' // Swap buffers
SDL_GL_SwapBuffers

END SUB
' =======================================================================================

' =======================================================================================
' Main
' =======================================================================================
FUNCTION PBMAIN () AS LONG

LOCAL pscreen AS SDL_Surface PTR
LOCAL nWidth, nHeight, bpp AS LONG
LOCAL lResult, bFullScreen AS LONG
   LOCAL szCaption AS ASCIIZ * 256
   LOCAL dwFlags AS DWORD
   LOCAL t, t0, fps AS DOUBLE
   LOCAL nFrames AS LONG

   szCaption = $WindowCaption   ' Window caption

' Ask the user which screen mode he prefers
lResult = MessageBox(%NULL, "Would you like to run in fullscreen mode?", _
"Start fullScreen?", %MB_YESNOCANCEL OR %MB_ICONQUESTION)
SELECT CASE lResult
CASE %IDCANCEL : EXIT FUNCTION
CASE %IDYES : bFullScreen = %TRUE
CASE %IDNO   : bFullScreen = %FALSE
END SELECT

' // Initialize SDL's subsystems - in this case, only video.
IF SDL_Init(%SDL_INIT_VIDEO) < 0 THEN
MSGBOX "Unable to init SDL: " & SDL_GetError()
EXIT FUNCTION
END IF

' // Attempt to create a 640x480 window
nWidth = 640 : nHeight = 480 : bpp = 16
IF bFullScreen THEN
dwFlags = %SDL_OPENGL OR %SDL_FULLSCREEN
ELSE
dwFlags = %SDL_OPENGL OR %SDL_RESIZABLE
END IF
pscreen = SDL_SetVideoMode(nWidth, nHeight, bpp, dwFlags)
SDL_WM_SetCaption szCaption, ""

' // If we fail, return error.
IF pscreen = %NULL THEN
SDL_Quit
MSGBOX "Unable to set the video mode: " & SDL_GetError()
EXIT FUNCTION
END IF

' // Set up the scene
SetupScene

' // Main loop
LOCAL done AS LONG
LOCAL uevent AS SDL_Event
WHILE done = %FALSE

' // Poll for events, and handle the ones we care about.
WHILE SDL_PollEvent(VARPTR(uevent))
SELECT CASE uevent.type
CASE %SDL_KEYDOWN
CASE %SDL_KEYUP
' // Quit if escape is pressed
IF uevent.key.keysym.sym = %SDLK_ESCAPE THEN
done = %TRUE
EXIT LOOP
END IF
CASE %SDL_VIDEORESIZE
' // Change the video mode to the new window size
nWidth = uevent.resize.w
nHeight = uevent.resize.h
pscreen = SDL_SetVideoMode(nWidth, nHeight, bpp, dwFlags)
IF TextureHandle THEN
glDeleteTextures(1, TextureHandle)
TextureHandle = 0
END IF
SetupScene
CASE %SDL_QUIT
done = %TRUE
EXIT LOOP
END SELECT
WEND

      IF ISFALSE bFullScreen THEN
         ' Get time and mouse position
         t = INT(TIMER)
         ' Calculate and display FPS (frames per second)
         IF t > t0 OR nFrames = 0 THEN
            fps = nFrames \ (t - t0)
            wsprintf szCaption, $WindowCaption & " (%i FPS)", BYVAL fps
            SDL_WM_SetCaption szCaption, szCaption
            t0 = t
            nFrames = 0
         END IF
         nFrames = nFrames + 1
      END IF

' // Draw the scene
DrawScene nWidth, nHeight

WEND

' Delete the texture
IF TextureHandle THEN glDeleteTextures(1, TextureHandle)

' Shut down SDL
SDL_Quit

END FUNCTION
' =======================================================================================


[José Roca]

 
This example illustrates how to map a bitmap image onto the six sides of a cube.

It is an adaptation of Nehe Lesson 06: http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=06

Code Select Expand


' SED_PBWIN - Use the PBWIN compiler
#COMPILE EXE
#DIM ALL
#INCLUDE ONCE "GLFW.INC"
#INCLUDE ONCE "GDIPUTILS.INC"

' =======================================================================================
' Main
' =======================================================================================
FUNCTION PBMAIN () AS LONG

   LOCAL hr, nWidth, nHeight, running, frames, x, y AS LONG
   LOCAL t, t0, fps AS DOUBLE
   LOCAL szTitlestr AS ASCIIZ * 200
   LOCAL xrot, yrot, zrot AS SINGLE
   LOCAL strTextureData AS STRING
   LOCAL TextureWidth AS LONG
   LOCAL TextureHeight AS LONG
   LOCAL glHandle AS DWORD

   ' Initialize GLFW
   glfwInit

   ' Open OpenGL window
   IF ISFALSE glfwOpenWindow(640, 480, 0, 0, 0, 0, 16, 0, %GLFW_WINDOW) THEN
      glfwTerminate
      EXIT FUNCTION
   END IF

   ' Specify clear values for the color buffers
   glClearColor 0.0!, 0.0!, 0.0!, 0.0!
   ' Specify the clear value for the depth buffer
   glClearDepth 1.0!
   ' Specify the value used for depth-buffer comparisons
   glDepthFunc %GL_LESS
   ' Enable depth comparisons and update the depth buffer
   glEnable %GL_DEPTH_TEST
   ' Select smooth shading
   glShadeModel %GL_SMOOTH

   ' Load bitmap texture from disk
   hr = GdiPlusLoadTexture("NeHe.bmp", TextureWidth, TextureHeight, strTextureData, %TRUE)

   ' Assign an OpenGL handle to this texture
   glGenTextures 1, glHandle

   ' Activate our newly created texture
   glEnable %GL_TEXTURE_2D
   glTexEnvf %GL_TEXTURE_ENV, %GL_TEXTURE_ENV_MODE, %GL_MODULATE
   glBindTexture %GL_TEXTURE_2D, glHandle

   ' Create the texture
   glTexParameteri %GL_TEXTURE_2D, %GL_TEXTURE_MAG_FILTER, %GL_LINEAR
   glTexParameteri %GL_TEXTURE_2D, %GL_TEXTURE_MIN_FILTER, %GL_LINEAR
   glTexImage2D %GL_TEXTURE_2D, 0, %GL_RGBA, TextureWidth, TextureHeight, 0, _
                %GL_RGBA, %GL_UNSIGNED_BYTE, BYVAL STRPTR(strTextureData)

   ' Enable sticky keys
   glfwEnable %GLFW_STICKY_KEYS

   ' Disable vertical sync (on cards that support it)
   glfwSwapInterval 0

   ' Main loop
   running = %TRUE
   frames = 0
   t0 = glfwGetTime

   DO WHILE running

      ' Get time and mouse position
      t = glfwGetTime
      glfwGetMousePos x, y
      ' Calculate and display FPS (frames per second)
      IF t - t0 > 1.0! OR frames = 0 THEN
         fps = frames / (t-t0)
         wsprintf szTitlestr, "NEHE Lesson 06 (%i FPS)", BYVAL fps
         glfwSetWindowTitle szTitlestr
         t0 = t
         frames = 0
      END IF
      frames = frames + 1

      '  Get window size (may be different than the requested size)
      glfwGetWindowSize nWidth, nHeight
      IF nHeight <= 0 THEN nHeight = 1

      ' Set viewport
      glViewport 0, 0, nWidth, nHeight

      ' Clear the screen and depth buffers
      glClear %GL_COLOR_BUFFER_BIT OR %GL_DEPTH_BUFFER_BIT

      ' Select and setup the projection matrix
      glMatrixMode %GL_PROJECTION
      glLoadIdentity

      ' Calculate the aspect ratio of the window
      gluPerspective 45.0!, nWidth/nHeight, 0.1!, 100.0!

      ' Select the modelview matrix
      glMatrixMode %GL_MODELVIEW
      glLoadIdentity

      glTranslatef 0.0!, 0.0!, -5.0!
      glRotatef xrot, 1.0!, 0.0!, 0.0!           ' Rotate on the x axis
      glRotatef yrot, 0.0!, 1.0!, 0.0!           ' Rotate on the y axis
      glRotatef zrot, 0.0!, 0.0!, 1.0!           ' Rotate on the z axis
      glBindTexture %GL_TEXTURE_2D, glHandle

      glBegin %GL_QUADS
         ' Front Face
         glTexCoord2f 0.0!, 0.0! : glVertex3f -1.0!, -1.0!,  1.0!      ' bottom left of the texture and quad
         glTexCoord2f 1.0!, 0.0! : glVertex3f  1.0!, -1.0!,  1.0!      ' bottom right of the texture and quad
         glTexCoord2f 1.0!, 1.0! : glVertex3f  1.0!,  1.0!,  1.0!      ' top right of the texture and quad
         glTexCoord2f 0.0!, 1.0! : glVertex3f -1.0!,  1.0!,  1.0!      ' top left of the texture and quad
         ' Back Face
         glTexCoord2f 1.0!, 0.0! : glVertex3f -1.0!, -1.0!, -1.0!      ' bottom right of the texture and quad
         glTexCoord2f 1.0!, 1.0! : glVertex3f -1.0!,  1.0!, -1.0!      ' top right of the texture and quad
         glTexCoord2f 0.0!, 1.0! : glVertex3f  1.0!,  1.0!, -1.0!      ' top left of the texture and quad
         glTexCoord2f 0.0!, 0.0! : glVertex3f  1.0!, -1.0!, -1.0!      ' bottom left of the texture and quad
         ' Top Face
         glTexCoord2f 0.0!, 1.0! : glVertex3f -1.0!,  1.0!, -1.0!      ' top left of the texture and quad
         glTexCoord2f 0.0!, 0.0! : glVertex3f -1.0!,  1.0!,  1.0!      ' bottom left of the texture and quad
         glTexCoord2f 1.0!, 0.0! : glVertex3f  1.0!,  1.0!,  1.0!      ' bottom right of the texture and quad
         glTexCoord2f 1.0!, 1.0! : glVertex3f  1.0!,  1.0!, -1.0!      ' top right of the texture and quad
         ' Bottom Face
         glTexCoord2f 1.0!, 1.0! : glVertex3f -1.0!, -1.0!, -1.0!      ' top right of the texture and quad
         glTexCoord2f 0.0!, 1.0! : glVertex3f  1.0!, -1.0!, -1.0!      ' top left of the texture and quad
         glTexCoord2f 0.0!, 0.0! : glVertex3f  1.0!, -1.0!,  1.0!      ' bottom left of the texture and quad
         glTexCoord2f 1.0!, 0.0! : glVertex3f -1.0!, -1.0!,  1.0!      ' bottom right of the texture and quad
         ' Right face
         glTexCoord2f 1.0!, 0.0! : glVertex3f  1.0!, -1.0!, -1.0!      ' bottom right of the texture and quad
         glTexCoord2f 1.0!, 1.0! : glVertex3f  1.0!,  1.0!, -1.0!      ' top right of the texture and quad
         glTexCoord2f 0.0!, 1.0! : glVertex3f  1.0!,  1.0!,  1.0!      ' top left of the texture and quad
         glTexCoord2f 0.0!, 0.0! : glVertex3f  1.0!, -1.0!,  1.0!      ' bottom left of the texture and quad
         ' Left Face
         glTexCoord2f 0.0!, 0.0! : glVertex3f -1.0!, -1.0!, -1.0!      ' bottom left of the texture and quad
         glTexCoord2f 1.0!, 0.0! : glVertex3f -1.0!, -1.0!,  1.0!      ' bottom right of the texture and quad
         glTexCoord2f 1.0!, 1.0! : glVertex3f -1.0!,  1.0!,  1.0!      ' top right of the texture and quad
         glTexCoord2f 0.0!, 1.0! : glVertex3f -1.0!,  1.0!, -1.0!      ' top left of the texture and quad
      glEnd

      xrot = xrot + 0.3!                         ' x axis rotation
      yrot = yrot + 0.2!                         ' y axis rotation
      zrot = zrot + 0.4!                         ' z axis rotation

      ' Swap buffers
      glfwSwapBuffers

      ' Check if the ESC key was pressed or the window was closed
      running = NOT glfwGetKey(%GLFW_KEY_ESC) AND glfwGetWindowParam(%GLFW_OPENED)

   LOOP

   ' Delete the texture
   IF glHandle THEN glDeleteTextures(1, glHandle)

   ' Close OpenGL window and terminate GLFW
   glfwTerminate

END FUNCTION
' =======================================================================================