Print Page - OpenGL Basics

Programming => Example Code => Graphics => Topic started by: Arnold on June 02, 2016, 06:34:51 AM

Title: OpenGL Basics
Post by: Arnold on June 02, 2016, 06:34:51 AM

Hi Charles,

you mentioned that you will use OpenGL with Oxide which gave me the idea to learn a little bit about this library. There are a lot of samples provided with Oxygenbasic, but somehow I am lacking the basics. So I started with the NeHe OpenGl tutorials as they are very well documented.

Lesson1 creates an empty OpenGL window. F1 will switch into fullscreen or windowed mode and the application waits for ESC or closing the window to exit. It is a template for the next lessons. I ported the VC code to OxygenBasic and it will work like the original code. I am not sure about two places:

In about line 157 DEVMODE dmScreenSettings is used. Must the structure be set to zeros or is this done automatically by OxygenBasic?

I used the include statements which I found in examples\OpenGL\other\OpenglChildWins1.o2bas. But I see that there are some more include files for using OpenGL. Could I use e.g. OpenglSceneFrame.inc instead and could I save some lines in the main code then?

Roland

Unfortunately the code exceeds the maximum allowed length so I will only show the two relevant places here:

Code: OxygenBasic

/*
 *    This Code Was Created By Jeff Molofee 2000
 *    A HUGE Thanks To Fredric Echols For Cleaning Up
 *    And Optimizing This Code, Making It More Flexible!
 *    If You've Found This Code Useful, Please Let Me Know.
 *    Visit My Site At nehe.gamedev.net
 */
 
' ported to OxygenBasic
 
#case capital
'
$ filename "lesson1.exe"
'#include "$/inc/RTL32.inc"
'#include "$/inc/RTL64.inc"
#include "$/inc/MinWin.inc"
'
s=error()
if s then
  print s
  end
end if
 
#define WINGDIAPI
#define APIENTRY
#define const
typedef word wchar_t
typedef sys ptrdiff_t
includepath +"$/inc/glo2/"
library "opengl32.dll"
include once "gl/gl.h"
'include once "gl/glext.h"
library "glu32.dll"
include once "gl/glu.h"
include once "gl/wgl.inc"
library ""
 
crlf=chr(13,10)
 
sys  hDC=null    // Private GDI Device Context
sys  hRC=null    // Permanent Rendering Context
sys  hWnd=null   // Holds Our Window Handle
sys  hInstance   // Holds The Instance Of The Application
 
bool keys[256]        // Array Used For The Keyboard Routine
bool active=TRUE      // Window Active Flag Set To TRUE By Default
bool fullscreen=TRUE  // Fullscreen Flag Set To Fullscreen Mode By Default
 
....
 
/*  This Code Creates Our OpenGL Window.  Parameters Are:         *
 *  title      - Title To Appear At The Top Of The Window         *
 *  width      - Width Of The GL Window Or Fullscreen Mode        *
 *  height      - Height Of The GL Window Or Fullscreen Mode      *
 *  bits      - Number Of Bits To Use For Color (8/16/24/32)      *
 *  fullscreenflag  - Use Fullscreen Mode (TRUE) Or Windowed Mode (FALSE)  */
 
function CreateGLWindow (string title, int width, int height, int bits, bool fullscreenflag) as bool
  GLuint    PixelFormat      // Holds The Results After Searching For A Match
  WNDCLASS  wc               // Windows Class Structure
  DWORD     dwExStyle        // Window Extended Style
  DWORD     dwStyle          // Window Style
  RECT      WindowRect       // Grabs Rectangle Upper Left / Lower Right Values
  WindowRect.left=0          // Set Left Value To 0
  WindowRect.right=width     // Set Right Value To Requested Width
  WindowRect.top=0           // Set Top Value To 0
  WindowRect.bottom=height   // Set Bottom Value To Requested Height
 
  fullscreen=fullscreenflag  // Set The Global Fullscreen Flag
 
  hInstance        = GetModuleHandle(null)               // Grab An Instance For Our Window
  wc.style         = CS_HREDRAW | CS_VREDRAW | CS_OWNDC  // Redraw On Size, And Own DC For Window.
  wc.lpfnWndProc   = @WndProc                            // WndProc Handles Messages
  wc.cbClsExtra    = 0                                   // No Extra Window Data
  wc.cbWndExtra    = 0                                   // No Extra Window Data
  wc.hInstance     = hInstance                           // Set The Instance
  wc.hIcon         = LoadIcon(null, IDI_WINLOGO)         // Load The Default Icon
  wc.hCursor       = LoadCursor(null, IDC_ARROW)         // Load The Arrow Pointer
  wc.hbrBackground = null                                // No Background Required For GL
  wc.lpszMenuName  = null                                // We Don't Want A Menu
  wc.lpszClassName = strptr "OpenGL"                     // Set The Class Name
 
  if not RegisterClass(&wc) then                  // Attempt To Register The Window Class  
    MessageBox(null,"Failed To Register The Window Class.","ERROR",MB_OK | MB_ICONEXCLAMATION)
    return FALSE                                  // Return FALSE
  end if
 
  if fullscreen then                                      // Attempt Fullscreen Mode?  
    DEVMODE dmScreenSettings                              // Device Mode
'    memset(&dmScreenSettings,0,sizeof(dmScreenSettings))  // Makes Sure Memory's Cleared
    dmScreenSettings.dmSize=sizeof(dmScreenSettings)      // Size Of The Devmode Structure
    dmScreenSettings.dmPelsWidth  = width                 // Selected Screen Width
    dmScreenSettings.dmPelsHeight = height                // Selected Screen Height
    dmScreenSettings.dmBitsPerPel = bits                  // Selected Bits Per Pixel
    dmScreenSettings.dmFields=DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT
 
 
...
 

Title: Re: OpenGL Basics
Post by: Arnold on June 02, 2016, 06:51:56 AM

This is the code of Lesson5. It is derived from Lesson1 with some additional code and it serves as a proof of concept. And again I wonder if I maybe could use different include files to save some lines in the main program?

Roland

.

Title: Re: OpenGL Basics
Post by: Peter on June 02, 2016, 09:43:56 AM

Hello,

Code: [Select]

include "gl.inc"
window 640,480,1
setframes 60

FontLoad "glfonts/font15.bmp"
float rtri				
float rquad				

while key(27)=0 
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) // Clear Screen And Depth Buffer
  
glLoadIdentity()                    // Reset The Current Modelview Matrix
glTranslatef(-1.5f,0.0f,-6.0f)      // Move Left 1.5 Units And Into The Screen 6.0
glRotatef(rtri,0.0f,1.0f,0.0f)      // Rotate The Triangle On The Y axis ( NEW )

glBegin(GL_TRIANGLES)               // Start Drawing A Triangle
glColor3f ( 1.0f, 0.0f, 0.0f)           // Red
glVertex3f( 0.0f, 1.0f, 0.0f)       // Top Of Triangle (Front)
glColor3f ( 0.0f, 1.0f, 0.0f)           // Green
glVertex3f(-1.0f,-1.0f, 1.0f)       // Left Of Triangle (Front)
glColor3f ( 0.0f, 0.0f, 1.0f)           // Blue
glVertex3f( 1.0f,-1.0f, 1.0f)       // Right Of Triangle (Front)
glColor3f ( 1.0f, 0.0f, 0.0f)           // Red
glVertex3f( 0.0f, 1.0f, 0.0f)       // Top Of Triangle (Right)
glColor3f ( 0.0f, 0.0f, 1.0f)           // Blue
glVertex3f( 1.0f,-1.0f, 1.0f)       // Left Of Triangle (Right)
glColor3f ( 0.0f, 1.0f, 0.0f)           // Green
glVertex3f( 1.0f,-1.0f,-1.0f)       // Right Of Triangle (Right)
glColor3f ( 1.0f, 0.0f, 0.0f)           // Red
glVertex3f( 0.0f, 1.0f, 0.0f)       // Top Of Triangle (Back)
glColor3f ( 0.0f, 1.0f, 0.0f)           // Green
glVertex3f( 1.0f,-1.0f,-1.0f)       // Left Of Triangle (Back)
glColor3f ( 0.0f, 0.0f, 1.0f)           // Blue
glVertex3f(-1.0f,-1.0f,-1.0f)       // Right Of Triangle (Back)
glColor3f ( 1.0f, 0.0f, 0.0f)           // Red
glVertex3f( 0.0f, 1.0f, 0.0f)       // Top Of Triangle (Left)
glColor3f ( 0.0f, 0.0f, 1.0f)           // Blue
glVertex3f(-1.0f,-1.0f,-1.0f)       // Left Of Triangle (Left)
glColor3f ( 0.0f, 1.0f, 0.0f)           // Green
glVertex3f(-1.0f,-1.0f, 1.0f)       // Right Of Triangle (Left)
glEnd()                             // Done Drawing The Pyramid

glLoadIdentity()                    // Reset The Current Modelview Matrix
glTranslatef(1.5,0.0,-7.0)          // Move Right 1.5 Units And Into The Screen 7.0
glRotatef(rquad,1.0,1.0,1.0)        // Rotate The Quad On The X axis ( NEW )
glBegin(GL_QUADS)                   // Draw A Quad
glColor3f ( 0.0f, 1.0f, 0.0f)           // Set The Color To Green
glVertex3f( 1.0f, 1.0f,-1.0f)       // Top Right Of The Quad (Top)
glVertex3f(-1.0f, 1.0f,-1.0f)       // Top Left Of The Quad (Top)
glVertex3f(-1.0f, 1.0f, 1.0f)       // Bottom Left Of The Quad (Top)
glVertex3f( 1.0f, 1.0f, 1.0f)       // Bottom Right Of The Quad (Top)
glColor3f ( 1.0f, 0.5f, 0.0f)           // Set The Color To Orange
glVertex3f( 1.0f,-1.0f, 1.0f)       // Top Right Of The Quad (Bottom)
glVertex3f(-1.0f,-1.0f, 1.0f)       // Top Left Of The Quad (Bottom)
glVertex3f(-1.0f,-1.0f,-1.0f)       // Bottom Left Of The Quad (Bottom)
glVertex3f( 1.0f,-1.0f,-1.0f)       // Bottom Right Of The Quad (Bottom)
glColor3f ( 1.0f, 0.0f, 0.0f)           // Set The Color To Red
glVertex3f( 1.0f, 1.0f, 1.0f)       // Top Right Of The Quad (Front)
glVertex3f(-1.0f, 1.0f, 1.0f)       // Top Left Of The Quad (Front)
glVertex3f(-1.0f,-1.0f, 1.0f)       // Bottom Left Of The Quad (Front)
glVertex3f( 1.0f,-1.0f, 1.0f)       // Bottom Right Of The Quad (Front)
glColor3f ( 1.0f, 1.0f, 0.0f)           // Set The Color To Yellow
glVertex3f( 1.0f,-1.0f,-1.0f)       // Top Right Of The Quad (Back)
glVertex3f(-1.0f,-1.0f,-1.0f)       // Top Left Of The Quad (Back)
glVertex3f(-1.0f, 1.0f,-1.0f)       // Bottom Left Of The Quad (Back)
glVertex3f( 1.0f, 1.0f,-1.0f)       // Bottom Right Of The Quad (Back)
glColor3f ( 0.0f, 0.0f, 1.0f)           // Set The Color To Blue
glVertex3f(-1.0f, 1.0f, 1.0f)       // Top Right Of The Quad (Left)
glVertex3f(-1.0f, 1.0f,-1.0f)       // Top Left Of The Quad (Left)
glVertex3f(-1.0f,-1.0f,-1.0f)       // Bottom Left Of The Quad (Left)
glVertex3f(-1.0f,-1.0f, 1.0f)       // Bottom Right Of The Quad (Left)
glColor3f ( 1.0f, 0.0f, 1.0f)           // Set The Color To Violet
glVertex3f( 1.0f, 1.0f,-1.0f)       // Top Right Of The Quad (Right)
glVertex3f( 1.0f, 1.0f, 1.0f)       // Top Left Of The Quad (Right)
glVertex3f( 1.0f,-1.0f, 1.0f)       // Bottom Left Of The Quad (Right)
glVertex3f( 1.0f,-1.0f,-1.0f)       // Bottom Right Of The Quad (Right)
glEnd()                             // Done Drawing The Quad

Text 1,-0.128,0.36,0.032,0.064,"LESSON 5"
rtri +=1.2        
rquad-=0.8           
SwapBuffer()
Wait 10
wend
winEnd

Title: Re: OpenGL Basics
Post by: Arnold on June 03, 2016, 12:05:24 AM

Hi Peter,

thank you for this code which is very helpful for me. I will use gl.inc with my studies of the tutorials too to find out the limits.

Would it make sense to use the option of fullscreen mode? I must admit switching to fullscreen mode and vice versa works terribly slow with my old notebook. (But it works). If it is not useful I will remove this option from the template's code.

Roland

Title: Re: OpenGL Basics
Post by: Peter on June 03, 2016, 03:06:15 AM

Quote

Would it make sense to use the option of fullscreen mode?

Hi Roland,

Why not!

A laptop has no resolution of 640 x 480.
You must take a resolution of 800 x 600 or 1024 x 768 or higher.

This is fullscreen :

include "gl.inc"
Window ( 1024, 768, 0 )

Demo:

Code: [Select]

include "gl.inc"
window 1024,768,0

fnt = FontLoad "glfonts/font21.bmp"
tex = TgaLoad  "tga/titus.tga"

float rx,ry,rz
float Mt_Diffuse [3] = {0.8, 0.8, 0.8, 1.0} 
float Mt_Ambient [3] = {0.3, 0.3, 0.3, 1.0}
float Mt_Specular[3] = {1.0, 1.0, 1.0, 1.0}
float Mt_Shiness [0] = {50.0}

float Lt_Position[3] = {0.0, 0.0, 10.0, 1.0}
float Lt_Diffuse [3] = {0.5, 0.5, 0.5, 0.5 }   
float Lt_Ambient [3] = {0.2, 0.2, 0.2, 1.0 }
float Lt_Specular[3] = {1.0, 1.0, 1.0, 1.0 }

glMaterialfv GL_FRONT, GL_SPECULAR , &Mt_Specular 
glMaterialfv GL_FRONT, GL_SHININESS, &Mt_Shiness 
glMaterialfv GL_FRONT, GL_DIFFUSE  , &Mt_Diffuse 
glMaterialfv GL_FRONT, GL_AMBIENT  , &Mt_Ambient 

glLightfv GL_LIGHT1,GL_DIFFUSE , &Lt_Diffuse 
glLightfv GL_LIGHT1,GL_AMBIENT , &Lt_Ambient 
glLightfv GL_LIGHT1,GL_SPECULAR, &Lt_Specular 
glLightfv GL_LIGHT1,GL_POSITION, &Lt_Position 

while Key(27)=0
Cls 0, 0, 0
glLoadIdentity
glTranslatef 0.0, 0.0, -6.0

glRotatef rx,1.0, 0.0, 0.0
glRotatef ry,0.0, 1.0, 0.0
glRotatef rz,0.0, 0.0, 1.0

glEnable GL_LIGHT1 
glEnable GL_LIGHTING 

glEnable GL_TEXTURE_2D
glBindTexture GL_TEXTURE_2D, tex 
glBegin  GL_QUADS 
glColor3f    1.0, 1.0, 0.0
glNormal3f   0.0, 1.0, 0.0  
glTexCoord2f 1.0, 1.0 : glVertex3f  1.0, 1.0,-1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f -1.0, 1.0,-1.0  
glTexCoord2f 0.0, 0.0 : glVertex3f -1.0, 1.0, 1.0  
glTexCoord2f 1.0, 0.0 : glVertex3f  1.0, 1.0, 1.0  
glColor3f    1.0, 0.0, 1.0 
glNormal3f   0.0,-1.0, 0.0  
glTexCoord2f 1.0, 1.0 : glVertex3f  1.0,-1.0, 1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f -1.0,-1.0, 1.0  
glTexCoord2f 0.0, 0.0 : glVertex3f -1.0,-1.0,-1.0  
glTexCoord2f 1.0, 0.0 : glVertex3f  1.0,-1.0,-1.0 
glColor3f    0.0, 0.0, 1.0 
glNormal3f   0.0, 0.0, 1.0  
glTexCoord2f 1.0, 1.0 : glVertex3f  1.0, 1.0, 1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f -1.0, 1.0, 1.0  
glTexCoord2f 0.0, 0.0 : glVertex3f -1.0,-1.0, 1.0  
glTexCoord2f 1.0, 0.0 : glVertex3f  1.0,-1.0, 1.0  
glColor3f    0.0, 1.0, 1.0 
glNormal3f   0.0, 0.0,-1.0  
glTexCoord2f 0.0, 0.0 : glVertex3f  1.0,-1.0,-1.0  
glTexCoord2f 1.0, 0.0 : glVertex3f -1.0,-1.0,-1.0  
glTexCoord2f 1.0, 1.0 : glVertex3f -1.0, 1.0,-1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f  1.0, 1.0,-1.0  
glColor3f    0.0, 1.0, 0.0 
glNormal3f  -1.0, 0.0, 0.0  
glTexCoord2f 1.0, 1.0 : glVertex3f -1.0, 1.0, 1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f -1.0, 1.0,-1.0  
glTexCoord2f 0.0, 0.0 : glVertex3f -1.0,-1.0,-1.0  
glTexCoord2f 1.0, 0.0 : glVertex3f -1.0,-1.0, 1.0  
glColor3f    1.0, 0.0, 0.0 
glNormal3f   1.0, 0.0, 0.0  
glTexCoord2f 1.0, 1.0 : glVertex3f 1.0, 1.0,-1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f 1.0, 1.0, 1.0  
glTexCoord2f 0.0, 0.0 : glVertex3f 1.0,-1.0, 1.0  
glTexCoord2f 1.0, 0.0 : glVertex3f 1.0,-1.0,-1.0  
glEnd 

glDisable GL_LIGHTING 
Text fnt,-0.160,0.350,0.032,0.032,"LIGHT CUBE"

rx +=0.6
ry +=0.5
rz +=0.4

SwapBuffer
wend
WinEnd

Title: Re: OpenGL Basics
Post by: Arnold on June 03, 2016, 04:02:13 AM

Hi Peter,

thank you. I see that Window (width, height, 0) is fullscreen and Window(width, height, 1) is windowed.

BTW: this program only works in fullscreen mode, whereas Lesson5 with gl.inc will work in a window and also in fullscreen. Does the difference result from the images?

Roland

Title: Re: OpenGL Basics
Post by: Peter on June 03, 2016, 02:30:43 PM

Quote

BTW: this program only works in fullscreen mode

Hi Roland,

No, this works also in windowed

another Demo:

Code: [Select]

include "gl.inc"
window 800,600,1  
setframes 60

FontLoad "glfonts/font16.bmp"  
FontLoad "glfonts/font25.bmp"  

t1=BmpLoad "bmp/titan.bmp"    
t2=BmpLoad "bmp/apple.bmp"    
t3=BmpLoad "bmp/bat.bmp"    

float xrot,yrot

Sub Quad2D(float x, y, z)
glPushMatrix
glTranslatef x, y, z 
glBegin(gl_Quads)
  glTexCoord2f  0.0, 0.0 : glVertex3f -1.0,-1.0, 0.0
  glTexCoord2f  1.0, 0.0 : glVertex3f  1.0,-1.0, 0.0
  glTexCoord2f  1.0, 1.0 : glVertex3f  1.0, 1.0, 0.0
  glTexCoord2f  0.0, 1.0 : glVertex3f -1.0, 1.0, 0.0
glEnd
glPopMatrix
End Sub

Sub Quad3D(float x, y, z, an, rx, ry, rz)
glPushMatrix
glTranslatef x, y, z
glRotatef an, rx, ry, rz
glBegin(GL_QUADS)
glTexCoord2f 0.0, 0.0 : glVertex3f -1.0,-1.0, 1.0  
glTexCoord2f 1.0, 0.0 : glVertex3f  1.0,-1.0, 1.0  
glTexCoord2f 1.0, 1.0 : glVertex3f  1.0, 1.0, 1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f -1.0, 1.0, 1.0  

glTexCoord2f 1.0, 0.0 : glVertex3f -1.0,-1.0,-1.0  
glTexCoord2f 1.0, 1.0 : glVertex3f -1.0, 1.0,-1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f  1.0, 1.0,-1.0  
glTexCoord2f 0.0, 0.0 : glVertex3f  1.0,-1.0,-1.0  

glTexCoord2f 0.0, 1.0 : glVertex3f -1.0, 1.0,-1.0  
glTexCoord2f 0.0, 0.0 : glVertex3f -1.0, 1.0, 1.0  
glTexCoord2f 1.0, 0.0 : glVertex3f  1.0, 1.0, 1.0  
glTexCoord2f 1.0, 1.0 : glVertex3f  1.0, 1.0,-1.0  

glTexCoord2f 1.0, 1.0 : glVertex3f -1.0,-1.0,-1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f  1.0,-1.0,-1.0  
glTexCoord2f 0.0, 0.0 : glVertex3f  1.0,-1.0, 1.0  
glTexCoord2f 1.0, 0.0 : glVertex3f -1.0,-1.0, 1.0  

glTexCoord2f 1.0, 0.0 : glVertex3f  1.0,-1.0,-1.0  
glTexCoord2f 1.0, 1.0 : glVertex3f  1.0, 1.0,-1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f  1.0, 1.0, 1.0  
glTexCoord2f 0.0, 0.0 : glVertex3f  1.0,-1.0, 1.0  

glTexCoord2f 0.0, 0.0 : glVertex3f -1.0,-1.0,-1.0  
glTexCoord2f 1.0, 0.0 : glVertex3f -1.0,-1.0, 1.0  
glTexCoord2f 1.0, 1.0 : glVertex3f -1.0, 1.0, 1.0  
glTexCoord2f 0.0, 1.0 : glVertex3f -1.0, 1.0,-1.0  
glEnd
glPopMatrix
End Sub

while Key(27)=0
Cls 0.0, 0.0, 0.0
glLoadIdentity
glTranslatef 0.0, 0.0, -10.0
glBegin(gl_Quads)
  glColor3f   1.0, 0.0, 1.0
  glVertex3f -1.0,-1.0, 0.0
  glColor3f   1.0, 1.0, 1.0
  glVertex3f  1.0,-1.0, 0.0
  glVertex3f  1.0, 1.0, 0.0
  glColor3f   1.0, 1.0, 1.0
  glVertex3f -1.0, 1.0, 0.0
glEnd

glEnable GL_TEXTURE_2D
glBindTexture GL_TEXTURE_2D, t2
Quad2D -3, 0, -1
glBindTexture GL_TEXTURE_2D, t3
Quad2D  3, 0, -1

glBindTexture GL_TEXTURE_2D, t1
Quad3D(-6, 4,-6, xrot,1,0,1)
Quad3D( 6,-4,-6, yrot,0,1,0)

glColor3ub 255,128,0
Text 1, -0.064,0.340, 0.032,0.064, "HELLO "  
glColor3ub 255,255,0
Text 1, -0.064,0.288, 0.032,0.064, " EAT  "  
glColor3ub 255,255,255
Text 1, -0.064, 0.240,0.032,0.064, "APPLES"  
Text 2, -0.384,-0.400,0.064,0.064, "opengl demo "

xrot +=1.0
yrot +=1.0

SwapBuffer
wend
winEnd

maximize this demo!

.

Title: Re: OpenGL Basics
Post by: Charles Pegge on June 03, 2016, 11:40:46 PM

Hi Roland,

Unlike C, OxygenBasic initializes all local variables to nulls. So you can omit this step when porting script from C.

OpenglSceneFrame.inc has many useful features, including Anti-Alias screen mode selection, low CPU usage, jpeg snap-shot, and object picking, which you are likely to need later on. It took me years to get it right, including substantial help from Mike Lobanovsky.

Unfortunately Opengl and 3d graphics are never going to be simple, but most programs require a similar base system.

Title: Re: OpenGL Basics
Post by: Arnold on June 05, 2016, 12:02:10 AM

Hi Peter,

this might be interesting. I tried several dimensions with my notebook and had these results with the above mentioned light cube demo:

include "gl.inc"

'window 720,480,1 'fails
'window 960,480,1 'fails
'window 1024,768,1 'fails
'window 1280,760,1 'fails

window 640,480,1 'success
'window 800,600,1 'success

...

I do not know the reason for the differences. Maybe my graphics card lacks some capabilities or I use the wrong settings. It is only a reminder that these differences can happen.

Roland

Title: Re: OpenGL Basics
Post by: Arnold on June 05, 2016, 12:36:53 AM

Hi Charles,

yes, OpenglSceneFrame.inc will be too much oversized for my purpose of porting the NeHe tutorials to OxygenBasic. But I also found /inc/WinUtil.inc with the Opengl option and I am experimenting with it. If I manage to combine the function MainWindow properly with the lesson1 framework this will save a lot of lines in the main code.

Roland

Title: Re: OpenGL Basics
Post by: Peter on June 05, 2016, 04:38:32 AM

Quote

this might be interesting. I tried several dimensions with my notebook and had these results with the above mentioned light cube demo:

Hi Roland

If you drive OpenGl3D, the ratio must match.
If you drive Opengl2D, you must not be careful.

Demo OpenGl 2D:

Code: [Select]

include "ogl.inc"
window 720,720,1
enable GL_POINT_SMOOTH

single x=300, y=200, e=0.05, dx, dy, tx, ty
sys i, j

while key(27)=0
cls 0,0,0
for j=0 to scrH() step 40
for i=0 to scrW() step 40
    color 255, 255, 255, 128
    circle i, j, 40, 1
next
next

tx = xMouse()-10
dx = tx-x
if abs(dx) >1 
   x = x+dx*e
end if
ty = yMouse()-10
dy = ty-y
if abs(dy) >1 
   y = y+dy*e
end if
color 255,194,183,200
circle x, y, 40, 2 
color 255,224,203,200
circle x, y, 30, 2 
color 255,244,255,200
fillcircle x, y, 20 

color 255,44,23,128
fillcircle scrW()/2, scrH()/2,75
color 23,44,255,128
fillcircle scrW()/2, scrH()/2-150,75
color 23,255,44,128
fillcircle scrW()/2, scrH()/2+150,75
setcaption "frames: " + getframes
redraw
wait 10
wend
winEnd

Title: Re: OpenGL Basics
Post by: Arnold on October 20, 2016, 06:03:41 AM

Hi Charles,

as always I will need some help.
By exploring consoleG.inc I found that this is in fact a complete library to develop all kind of OpenGl applications and as it is included in GraphUtil.inc there are still some more possibilities provided.

I tried out this small example:

Code: OxygenBasic

$ Title "OpenGl Framework"
 
% width     300
% height    100
 
'screen dimensions
'% width = GetSystemMetrics (SM_CXSCREEN)
'% height = GetSystemMetrics (SM_CYSCREEN)
 
'% ExplicitMain
                                 ,
'% ScaleUp
'% PlaceCentral
'% AnchorCentral
'% NoEscape
 
'include "$/inc/consoleG.inc"
includepath "$/inc/"
include "GraphUtil.inc"
 
sub main()
  print "Hello World from OpenGl"
end sub
 
'BeginScript 'does nothing?
EndScript  'starts MainWindow width, height, WS_OVERLAPPEDWINDOW
 
'MainWindow width, height, WS_POPUP  'Alt-F4 or Esc
 

What does %% ExplicitMain and %% ScaleUp do? Can %% PlaceCentral and %% AchorCentral be used together? What is the purpose of BeginScript?

The problem with this example is the changing size of the font. Can I influence this or can I add additional code for using a fixed sized font? You have already provided:
BuildFont, print3D, gprint in OpenglSceneFrame.inc
print, output in ConsoleG.inc

If I cannot use these functions I would like to use and add this code from NeHe lesson 13 somehow:

Code: [Select]

GLuint  base                // Base Display List For The Font Set

sub BuildFont()                                        // Build Our Bitmap Font
    sys font                                           // Windows Font ID
    sys oldfont                                        // Used For Good House Keeping

    base = glGenLists(255)                          // Storage For Characters

    font = CreateFont(    -24,                         // Height Of Font
                        0,                             // Width Of Font
                        0,                             // Angle Of Escapement
                        0,                             // Orientation Angle
                        FW_BOLD,                       // Font Weight
                        FALSE,                         // Italic
                        FALSE,                         // Underline
                        FALSE,                         // Strikeout
                        ANSI_CHARSET,                  // Character Set Identifier
                        OUT_TT_PRECIS,                 // Output Precision
                        CLIP_DEFAULT_PRECIS,           // Clipping Precision
                        ANTIALIASED_QUALITY,           // Output Quality
                        FF_DONTCARE|DEFAULT_PITCH,     // Family And Pitch
                        "Courier New")                 // Font Name

    oldfont = SelectObject(wglGetCurrentDC(), font)           // Selects The Font We Want
    wglUseFontBitmapsA(wglGetCurrentDC(), 32, 255-32, base)   // Builds Characters Starting At Character 32
    SelectObject(wglGetCurrentDC(), oldfont)                  // Selects The Font We Want
    DeleteObject(font)                                        // Delete The Font
end sub

sub KillFont()                                          // Delete The Font List
    glDeleteLists(base, 255)                            // Delete All Characters
end sub

sub glPrint(char *text)                           // Custom GL "Print" Routine
   if len(text) = 0 then return                        // If There's No Text

   glPushAttrib(GL_LIST_BIT)                           // Pushes The Display List Bits
   glListBase(base - 32)                               // Sets The Base Character to 32
   glCallLists(len(text), GL_UNSIGNED_BYTE, text)      // Draws The Display List Text
   glPopAttrib()                                       // Pops The Display List Bits
end sub

What would be the best way to add some more functionality? E.g. I would like to use a F(num) key to change the Windows style and toggle (ShowWindow) between Fullscreen and original size of the window.

Roland

Title: Re: OpenGL Basics
Post by: Charles Pegge on October 21, 2016, 12:32:17 AM

Hi Roland,

%PlaceCentral and %AnchorCentral locates 0,0 at the centre of the window, otherwise 0,0 locates to the top left margin.

%ScaleUp enlarges the image as the window is stretched, otherwise enlargement is limited.

%ExplicitMain requires your code to call MainWindow (via Endscript). This ensures that the Program traverses any global variable initializations and any classes you may define,

BeginScript is reserved for future functionality

I have not explored changing the windows style, but you can do so by overriding EndScript:
currently: MainWindow width,height,WS_OVERLAPPEDWINDOW

Here is an example of Text tranformations (with F4 function key)

Code: [Select]

  % Title "ConsoleG Demo"
  % Animated
 '% ScaleUp
  % PlaceCentral
  % AnchorCentral
  include "$\inc\ConsoleG.inc"

  BeginScript

  sub main
  ========

  pushstate
  scale 2,3
  color 1,.5,0,1
  printl "Hello"
  scale 2, 1.25
  if key(VK_F4) then rotatez -30
  printl "World!"
  popstate

  end sub 'main

  EndScript

Title: Re: OpenGL Basics
Post by: Arnold on October 21, 2016, 03:43:29 PM

Hi Charles,

based on your example it is already possible to experiment a little bit with the World. I added some options for the arrow keys and for n, m:

Code: [Select]

  % Title "ConsoleG Demo"
  % Animated
 '% ScaleUp
  % PlaceCentral
  % AnchorCentral
  include "$\inc\ConsoleG.inc"
  
  'Keys: Esc, arrow-keys, n,m, F4

  BeginScript

  sub main
  ========
  static int z, y, x
  
  pushstate
  scale 2, 3
  color 1,.5,0,1
  print "Hello "

  scale 2, 1.25
  if key(VK_UP) then x-=2
  if key(VK_DOWN) then x+=2 
  if key(VK_RIGHT) then y-=2
  if key(VK_LEFT) then y+=2
  if key(77) then z-=2      'm,M
  if key(78) then z+=2      'n,N
  if key(VK_F4) then x=0 : y=0 : z=0 

  rotatex x
  rotatey y
  rotatez z 
  
  print "World!"
  popstate

  end sub 'main

  EndScript

Some keys can be used simultaneously. Unfortunately I have not yet found out how to use the timer functions correctly which you already generated. Is there a simple way to start and stop moving the World?

Roland

Title: Re: OpenGL Basics
Post by: Charles Pegge on October 23, 2016, 12:28:09 PM

Hi Roland,

There are some deep issues concerning reliable timing, which I am attempting to address right now. I don't think the windows timer should be used at all, nor should one rely on the 60hz/30hz frame rate.

Multimedia time is a distinct possibility

https://msdn.microsoft.com/en-us/library/windows/desktop/dd743612(v=vs.85).aspx

When you say 'stop the world' do you mean freeze animation or do you mean shut down?

Title: Re: OpenGL Basics
Post by: Arnold on October 23, 2016, 01:23:17 PM

Hi Charles,

I just saw your message and I must still check the link you indicated.

This is the current state of my experiments with the ConsoleG demo. I changed the behaviour of the arrow keys and n,m to start animation, F4 resets the values and F12 toggles between fullscreen and windowed mode. There are two problems though:

Code: OxygenBasic

$ FileName "ConsoleGDemo.exe"
 
'include "$/inc/RTL32.inc"
 
  % Title "ConsoleG Demo"
  % Animated
 '% ScaleUp
  % PlaceCentral
  % AnchorCentral
    
  % width 640
  % height 480
  
  include "$\inc\ConsoleG.inc"
  
  'Keys: Esc, arrow-keys, n,m, F4
  '      F12 toggles fullscreen and windowed mode
 
 
'screen dimensions
int swidth  = GetSystemMetrics (SM_CXSCREEN)
int sheight = GetSystemMetrics (SM_CYSCREEN)
bool fullscreen=FALSE
 
 
  BeginScript
 
  function WndMessages( hWndMain, wMsg, wParam, lparam ) as sys, link WndProcExtra
  ============================================================================
  'sys hWndMain in WinUtil.inc
  'byte lastkey in WinUtil.inc
  static int wleft, wtop, wwidth, wheight
  RECT wrc
  
  select wMsg
 
  case WM_KEYUP    
     if lastkey = 123 then 'F12
       fullscreen = not fullscreen
       if fullscreen then
         GetWindowRect(hwndMain,@wrc)
         wleft=wrc.left : wtop=wrc.top : wwidth=wrc.right-wrc.left : wheight=wrc.bottom-wrc.top           
         SetWindowLong(hWndMain, GWL_STYLE, WS_POPUP)
         MoveWindow(hWndMain,0,0,swidth,sheight,1)
         ShowWindow(hWndMain, SW_RESTORE)
         UpdateWindow(hWndMain)
       else
         SetWindowLong(hWndMain, GWL_STYLE, WS_OVERLAPPEDWINDOW)   
         MoveWindow(hWndMain,wleft,wtop,wwidth,wheight,1)   
         ShowWindow(hWndMain, SW_RESTORE)
         UpdateWindow(hWndMain)
       end if
     end if
  end select
  end function
 
  sub main
  ========
  static float x,y,z
  static float xspeed, yspeed, zspeed  
 
  pushstate
  scale 2, 3
  color 1,.5,0,1
  print "Hello "
  
  scale 2, 1.25  
  if key(VK_UP) then xspeed-=0.2
  if key(VK_DOWN) then xspeed+=0.2 
  if key(VK_RIGHT) then yspeed-=0.2
  if key(VK_LEFT) then yspeed+=0.2
  if key(77) then zspeed-=0.2      'm,M
  if key(78) then zspeed+=0.2      'n,N
  if key(VK_F4) then x = y = z = xspeed = yspeed = zspeed = 0.0 
  
  rotatex x : x+=xspeed : if abs(x)>360 then x=0
  rotatey y : y+=yspeed : if abs(y)>360 then y=0
  rotatez z : z+=zspeed : if abs(z)>360 then z=0
  
  print "World!"
  popstate
 
  end sub 'main
 
  EndScript
 

This will work for slow computers. For new fast computers the values for xspeed, yspeed and zspeed must be changed to 0.002 instead of 0.2. Unfortunately I still have not found out how to use timing but I think I will need it in some way.
It seems that I can only test F11 or F12 if I use lastkey to check the value. Is there another way to use e.g. F5?

Roland

.

Title: Re: OpenGL Basics
Post by: Charles Pegge on October 25, 2016, 12:08:01 AM

You can use any number of keys (depending on fingers and nose :) ) simultaneously. The VK_SHIFT key is useful for fast movement.

Here is a macro from consoleG.inc, which is used to control moveable objects with the keyboard.

Code: [Select]

  macro MoveThisWithKeys(mv,an,k)
  ===============================
  if key[VK_CONTROL]
    if key[37] then a.y-=an : k=2  ' left
    if key[39] then a.y+=an : k=2  ' right
    if key[38] then a.x-=an : k=2  ' up
    if key[40] then a.x+=an : k=2  ' down
    if key[33] then a.z+=an : k=2  ' PgUp
    if key[34] then a.z-=an : k=2  ' PgDn
    if key[36] 
      a.x=0. : a.y=0. : a.z=0. : k=3 'HOME'
    end if
    static float m
    m=1.0+m*.01
    if key[0xbd] then s.x/=m : s.y/=m : s.z/=m : k=1  ' -
    if key[0xbb] then s.x*=m : s.y*=m : s.z*=m : k=1  ' =
  else
    scope
    static float m
    if key[VK_SHIFT] then m=mv*3 else m=mv
    if key[37] then p.x-=m : k=1  ' left
    if key[39] then p.x+=m : k=1  ' right
    if key[38] then p.y+=m : k=1  ' up
    if key[40] then p.y-=m : k=1  ' down
    if key[33] then p.z-=m : k=1  ' PgUp
    if key[34] then p.z+=m : k=1  ' PgDn
    '
  end if
  end scope
  end macro

Title: Re: OpenGL Basics
Post by: Arnold on October 28, 2016, 12:29:22 AM

Hi Charles,

I assume the macro above (and MoveThisWithMouse) can be used generally for moving things around and also as a pattern for similar actions? I used the part for increasing / decreasing speed faster.
My purpose for enhancing your little demo was to check what could be done with WndProcExtra and how to add some events.
Although I am far away from understanding all the tools you provided for OpenGl the ConsoleG demo works already very nice in my opinion. It will be interesting to investigate in some more areas. For instance using ImgWin.inc and perhaps adding some user functions it should already be possible to write NeHe lessons 1 - 20 using the provided tools of OxygenBasic.

Roland

Code: [Select]

$ FileName "ConsoleGDemo.exe"

'include "$/inc/RTL32.inc"

  % Title "ConsoleG Demo - F1 for Help"
  % Animated
 '% ScaleUp
  % PlaceCentral
  % AnchorCentral
    
  % width 640
  % height 480
  
  include "$\inc\ConsoleG.inc"
  
  'Keys: Esc, arrow-keys, n,m, F4, +,-
  '      F12 toggles fullscreen and windowed mode


'screen dimensions
int swidth  = GetSystemMetrics (SM_CXSCREEN)
int sheight = GetSystemMetrics (SM_CYSCREEN)
bool fullscreen=FALSE

  BeginScript

  sub main
  ========
  static float x,y,z
  static float xspeed, yspeed, zspeed
  static float m 
  static int wleft, wtop, wwidth, wheight
  RECT wrc

  'F1 HELP
  '
  if key[0x70]
    pushstate
    move 5,14
    color 1,.8,.5
    scale  1.5,1.0
    printl "Active Keys:"
    scale  1/1.5,1.0
    printl
    printl "ALT-F4, ESC - Exit"
    printl "F12 - Toggle Fullscreen"
    printl "Arrow Keys, N, M: "
    printl "Start moving and"
    printl "   increase or decrease speed"
    printl "+ increase move with faster speed"
    printl "- decrease move with faster speed"
    printl "F4 - Stop and reset values"
    printl "F1 - This help"
    printl
    popstate
  end if
  '
  lastkey=0
  lastchar=0

  pushstate
  scale 2, 3
  color 1,.5,0,1
  print "Hello "
  
  scale 2, 1.25    
  if key(VK_UP) then key(VK_UP)=FALSE : xspeed-=0.01
  if key(VK_DOWN) then key(VK_DOWN)=FALSE : xspeed+=0.01 
  if key(VK_RIGHT) then key(VK_RIGHT)=FALSE : yspeed-=0.01
  if key(VK_LEFT) then key(VK_LEFT)=FALSE : yspeed+=0.01
  if key(77) then key(77)=FALSE : zspeed-=0.01      'm,M
  if key(78) then key(78)=FALSE : zspeed+=0.01      'n,N
  if key(VK_F4) then x = y = z = xspeed = yspeed = zspeed = 0.0 

  if key(VK_ADD) or key(187) then       '+
    key(VK_ADD) = FALSE : key(187)=FALSE
    m=1.0+m*.1
    xspeed*=m : yspeed*=m : zspeed*=m
  end if
  if key(VK_SUBTRACT) or key(189) then  '-
    key(VK_SUBTRACT)=FALSE: key(189)=FALSE
    xspeed/=m : yspeed/=m : zspeed/=m
  end if

  if key(VK_F12) then
    key(VK_F12) = FALSE
    fullscreen = not fullscreen
    if fullscreen then
      GetWindowRect(hwndMain,@wrc)
      wleft=wrc.left : wtop=wrc.top : wwidth=wrc.right-wrc.left : wheight=wrc.bottom-wrc.top           
      SetWindowLong(hWndMain, GWL_STYLE, WS_POPUP)
      MoveWindow(hWndMain,0,0,swidth,sheight,1)
      ShowWindow(hWndMain, SW_RESTORE)
    else
      SetWindowLong(hWndMain, GWL_STYLE, WS_OVERLAPPEDWINDOW)   
      MoveWindow(hWndMain,wleft,wtop,wwidth,wheight,1)   
      ShowWindow(hWndMain, SW_RESTORE)
    end if
  end if
  
  rotatex x : x+=xspeed : if x>=360 then x-=360 : if x<=0 then x+=360
  rotatey y : y+=yspeed : if y>=360 then y-=360 : if y<=0 then y+=360
  rotatez z : z+=zspeed : if z>=360 then z-=360 : if z<=0 then z+=360
  
  print "World!"
  popstate

  end sub 'main

  EndScript

Title: Re: OpenGL Basics
Post by: Charles Pegge on October 28, 2016, 02:18:29 AM

Hi Roland,

MoveThisWithMouse is used by the moveableObject class, managing specific variables.

PineCone.o2bas and MoveableObj.o2bas demonstrate how this class is used.

But I am adding a few more tricks to ConsoleG:

In a single line of code, UserMovement will allow you to move any piece of geometry or text, like so:

Code: [Select]

  pushstate
  color 1,.5,0,1
  UserMovement m1,100 'identity in steps of 100
  scale 2, 3
  print "Hello "
  popstate
  move 5

  pushstate
  color 1,1,0,1
  UserMovement m2,200
  scale 4
  print "World"
  popstate

I have also added some timer and time keeping functions for precise management of events, independend of the frame rate or the windows WM_timer.

Will post soon but it's hard to know when to stop :)

Title: Re: OpenGL Basics - ConsoleCommand
Post by: Arnold on October 28, 2016, 05:05:43 AM

Hi Charles,

I refer to projectsA\OpenglCns\ConsoleComand.o2bas. If I try to run the example there is an error message in line 18 (WaitForMultipleObjects). If I comment out line 18 or use line 18 this way:

WaitForMultipleObjects 1,@infp.hthread, '1,-1

the program would run in some way but I am not sure if this is correct. You used WaitForMultipleObjects in some other demos and there is no problem in these cases. I also noticed that not all ansi characters are shown correctly e.g. the Umlauts like Ä,ä, Ü,ü, Ö,ö. etc.
Is there a reason why WaitForMultipleObjects does not work correctly in this special case? The program does work with a previous version of Oxygen, maybe it works with Oxygen in progress too? BTW the demo calls cmd.exe which if called separately will show the text properly.

Roland

PS: I tested PineCone.o2bas and MoveableObj.o2bas. Using keys, mouse buttons and wheel work perfectly on my system. It is amazing to see how much is possible with comparatively few lines of code.

.

Title: Re: OpenGL Basics
Post by: Charles Pegge on October 28, 2016, 08:29:09 AM

Hi Roland,

I'm using ANSI_CHARSET. Could that be the problem for the missing accented characters?

from openglsceneframe.inc

Code: [Select]

  sub BuildFont (sys hWnd,hDC,hRC, string name, sys weight, base)
  ===============================================================
  indexbase 0
  LOGFONT   glFont
  sys       glFontHandle
  '
  glFont.lfHeight         = 1                             'Height Of Font
  glFont.lfWeight         = weight                        'Font Weight FW_BOLD etc
  glFont.lfCharSet        = ANSI_CHARSET                  'Character Set Identifier
  glFont.lfOutPrecision   = OUT_TT_PRECIS                 'Output Precision
  glFont.lfClipPrecision  = CLIP_DEFAULT_PRECIS           'Clipping Precision
  glFont.lfQuality        = ANTIALIASED_QUALITY           'Output Quality
  glFont.lfPitchAndFamily = FF_DONTCARE or DEFAULT_PITCH  'Family And Pitch
  glFont.lfFaceName       = name    ' "Arial" "Lucida Console" "Consolas" ' "Courier New"    'Font Name
  '
  glFontHandle = CreateFontIndirect(@glFont)
  glFontHandle = SelectObject(hDC, glFontHandle)
  wglUseFontOutlinesA (hDC, 0, 256, base, 0.0, .25, WGL_FONT_POLYGONS, @gmf[base-1024])
  DeleteObject(glFontHandle)
  end sub

Title: Re: OpenGL Basics
Post by: Arnold on October 28, 2016, 11:01:35 AM

Hi Charles,

Nehe lesson 14 builds the fonts almost the same way and I have no problems. Also not in ConsoleText.o2bas when entering text.
But I noticed that the output of the command is saved to temp.txt and here the special chars are saved differently too. So I tried in a console window:
help > tmp.txt
and voila - tmp.txt shows the same output as temp.txt. So nothing is wrong with Oxygenbasic. Maybe I must add an additional driver for the saving purpose, but this is not worthwhile for this old system.

Roland

Title: Re: OpenGL Basics
Post by: Charles Pegge on November 01, 2016, 03:18:53 AM

Hi Roland,

This is the ANSI character set depicted thru OpenGl. As you can see, there are a few missing characters in the upper range.

.

Title: Re: OpenGL Basics
Post by: Arnold on November 01, 2016, 05:53:00 AM

Hi Charles,

actually this was my fault. I did not realize at once that CommandConsole.o2bas redirects the output to temp.txt which does not work fully with cmd.exe, even not in Windows 10. It would work with powershell.exe though. If I open temp.txt with the windows editor, some special characters are shown differently, but if I use in a console window the command: type temp.txt these special chars are displayed correctly too (strange). I tried to change to some different codepages using chcp.exe but the results were the same. Probably this is a strange historical caused behaviour of Dos / Windows.
The BuildFont procedure itself should work correctly. I can test this with ConsoleText.o2bas in folder OpenglCns. When I enter text in the input field the characters are displayed correctly.

The function WaitForMultipleObjects in ConsoleCommand.o2bas is more interesting. There was no error reported using A41 26/07/2015. Will it work for Oxygen in progress too?

Roland

Title: Re: OpenGL Basics
Post by: Charles Pegge on November 02, 2016, 09:36:56 AM

Hi Roland,

I have not seen any problems with WaitForMultipleObjects. I have been checking for subtle syntax glitches though.

I want to include a few more examples before releasing:

ControlPanelArray: (where OOP becomes a necessity)

.

Oxygen Basic

Programming => Example Code => Graphics => Topic started by: Arnold on June 02, 2016, 06:34:51 AM