vertex buffer objects for OpenGl 1.5

[primo]

Hi Petr
i want to implement this VBO code in
https://en.wikipedia.org/wiki/Vertex...ing_OpenGL_2.1
for opengl 1.5 to 2.1
i have added #Include "%app_includepath%\thinBasic_GLEXT.inc"
but i get errors about the function glGenBuffers:

A general declared function or sub has no process address. See DECLARE SET ADDRESS help for more info.

i have searched the file "thinBasic_GLEXT.inc" and the glGenBuffers is declared like:
DECLARE SUB glGenBuffers ( BYVAL Par1 AS GLsizei, BYREF Par2 AS GLuint)
so what is the mystery?
i have searched for glGenBuffers inside opengl32.dll which is located my windows xp32 system folder and can't find the glGenBuffers inside the DLL, the only place i find it is inside my nvidea card driver software. i also find it in mesa opengl32.dll https://fdossena.com/?p=mesa/index.frag in which its opengl32.dll have big size > 16MB and seems to contains all extensions.
best regards

Uses "tbgl", "MATH"
     
#Def %GL_GLEXT_PROTOTYPES
#Include "%app_includepath%\thinbasic_gl.inc"
#Include "%app_includepath%\thinbasic_glu.inc"
#Include "%app_includepath%\thinbasic_WGL.inc" 
#Include "%app_includepath%\thinBasic_GLEXT.inc"

Dim HglGenBuffers As DWord = TBGL_GetProcAddress("glGenBuffers") 
Declare Set Address glGenBuffers, HglGenBuffers 
     
  Dim hwnd As DWord 
       
  hwnd = TBGL_CreateWindowEx("glDrawArrays example - esc to exit", 600, 600, 32, 0)
  TBGL_ShowWindow
  TBGL_ResetKeyState()
   
'try float data[] = {0.0, 1.0, 0.0, -1.0, -1.0, 0.0, 1.0, -1.0, 0.0}
Global data(9) As Single
Array Assign data = 1.0, 0.0, 1.0, 0.0, 0.0, -1.0, -1.0, 0.0, 1.0

'Create a New VBO And use the variable id To store the VBO id  
Global triangleVBO As DWord
glGenBuffers(1, VarPtr(triangleVBO)) ' //Make the New VBO active
glBindBuffer(%GL_ARRAY_BUFFER, triangleVBO)
'Upload vertex data To the video device 
glBufferData(%GL_ARRAY_BUFFER, SizeOf(data), data, %GL_STATIC_DRAW)
'Make the New VBO active. Repeat here incase changed since initialisation
glBindBuffer(%GL_ARRAY_BUFFER, triangleVBO)
  
  While TBGL_IsWindow(hwnd)
     TBGL_ClearFrame
     
    display
    TBGL_DrawFrame
    If TBGL_GetWindowKeyState( hwnd, %VK_ESCAPE) Then Exit While
  Wend
     
  TBGL_DestroyWindow
 
'=================================================================================
 
'--------------------------------------------------------
'--------------------------------------------------------   
Sub display()
 
glMatrixMode(%GL_PROJECTION)
glLoadIdentity()
gluPerspective(60.0, 800/600, 1.0, 100.0)
glMatrixMode(%GL_MODELVIEW)
'glTranslatef(0, 0, -40)
glShadeModel(%GL_SMOOTH) 
glEnable(%GL_DEPTH_TEST)
gluLookAt( 0, 1, 1,
           0,  1, 0,
            0, 1,  0 ) 
    glclear(%gl_color_buffer_bit)
       
    TBGL_Rotate GetTickCount/30,0,1,0
      
'Initialise VBO - do only once, at start of program
'Create a variable To hold the VBO identifier GLuint triangleVBO;
'Vertices of a triangle (counter-clockwise winding)  

'Draw Triangle from VBO - Do Each time Window, view point Or data changes 
'Establish its 3 coordinates per vertex With zero stride In This Array; necessary here
 glVertexPointer(3, %GL_FLOAT, 0, NULL)
'Establish Array Contains vertices (Not normals, colours, texture coords etc)
 glEnableClientState(%GL_VERTEX_ARRAY)
'Actually Draw the triangle, giving the Number of vertices provided
 glDrawArrays(%GL_TRIANGLES, 1, 9)
 'Force display To be drawn Now
 'glFlush; 
        
 glClear(%GL_COLOR_BUFFER_BIT Or %GL_DEPTH_BUFFER_BIT)
 glClearColor(1, 1, 1, 1)

 glDisableClientState(%GL_VERTEX_ARRAY)  
  '**************************************************
       
   
  End Sub

Edit: i have added :

Dim HglGenBuffers As DWord = TBGL_GetProcAddress("glGenBuffers") 
Declare Set Address glGenBuffers, HglGenBuffers

but still can't access glGenBuffers

Edit2:
my Last try, but still can't access the glGenBuffers
my card support VBO as i can run the VBO examples in other languages.

Uses "tbgl"

#Def %GL_GLEXT_PROTOTYPES
#Include "%app_includepath%\thinbasic_gl.inc"
#Include "%app_includepath%\thinbasic_glu.inc"
#Include "%app_includepath%\thinBasic_GLEXT.inc"
#Include "%app_includepath%\thinbasic_WGL.inc" 

Declare Set Address glGenBuffers,   wglGetProcAddress("glGenBuffers")   
Declare Set Address glBindBuffer,   wglGetProcAddress("glBindBuffer") 
Declare Set Address glBufferData,   wglGetProcAddress("glBufferData")  
  
Dim hwnd As DWord

hwnd = TBGL_CreateWindowEx("glDrawArrays example - esc to exit", 600, 600, 32, 0)
TBGL_ShowWindow
TBGL_ResetKeyState()

'try float data[] = {0.0, 1.0, 0.0, -1.0, -1.0, 0.0, 1.0, -1.0, 0.0}
Global data(9) As Single
Array Assign data = 1.0, 0.0, 1.0, 0.0, 0.0, -1.0, -1.0, 0.0, 1.0

'Create a New VBO And use the variable id To store the VBO id 
Dim triangleVBO As DWord
glGenBuffers(1, triangleVBO) ' //Make the New VBO active
glBindBuffer(%GL_ARRAY_BUFFER, triangleVBO)
'Upload vertex data To the video device 
glBufferData(%GL_ARRAY_BUFFER, SizeOf(data), data, %GL_STATIC_DRAW)
'Make the New VBO active. Repeat here incase changed since initialisation
glBindBuffer(%GL_ARRAY_BUFFER, triangleVBO)

While TBGL_IsWindow(hwnd)
TBGL_ClearFrame

display
TBGL_DrawFrame
If TBGL_GetWindowKeyState( hwnd, %VK_ESCAPE) Then Exit While
Wend

TBGL_DestroyWindow

'=================================================================================

Sub display()

glMatrixMode(%GL_PROJECTION)
glLoadIdentity()
gluPerspective(60.0, 800/600, 1.0, 100.0)
glMatrixMode(%GL_MODELVIEW)
'glTranslatef(0, 0, -40)
glShadeModel(%GL_SMOOTH) 
glEnable(%GL_DEPTH_TEST)
gluLookAt( 0, 1, 1,
0, 1, 0,
0, 1, 0 ) 
glclear(%gl_color_buffer_bit)

TBGL_Rotate GetTickCount/30,0,1,0

'Initialise VBO - do only once, at start of program
'Create a variable To hold the VBO identifier GLuint triangleVBO;
'Vertices of a triangle (counter-clockwise winding) 

'Draw Triangle from VBO - Do Each time Window, view point Or data changes 
'Establish its 3 coordinates per vertex With zero stride In This Array; necessary here
glVertexPointer(3, %GL_FLOAT, 0, NULL)
'Establish Array Contains vertices (Not normals, colours, texture coords etc)
glEnableClientState(%GL_VERTEX_ARRAY)
'Actually Draw the triangle, giving the Number of vertices provided
glDrawArrays(%GL_TRIANGLES, 1, 9)
'Force display To be drawn Now
'glFlush; 

glClear(%GL_COLOR_BUFFER_BIT Or %GL_DEPTH_BUFFER_BIT)
glClearColor(1, 1, 1, 1)

glDisableClientState(%GL_VERTEX_ARRAY) 
'**************************************************

End Sub

[Petr Schreiber]

Hi Primo,

thanks for reaching me. I think you must perform the Declare Set Address once you have active OpenGL context, that is, after TBGL_CreateWindowEx.

Then, I think you need to pass pointer to glBufferData, let's try something like:

glBufferData(%GL_ARRAY_BUFFER, SizeOf(data), varptr(data(1)), %GL_STATIC_DRAW)

I think that should boost you in the right direction


Petr

[primo]

You are so nice Petr to provide a solution, Thank you.
yes it works now with the suggestions. following is the new code
but there is the problem of the triangle colors, it seems the color is sticky and can't be changed . as an example in line 34:
data(1).red = 1: data(1).green = 0: data(1).blue=0
if i changed red to 0 and green to 1 i can't get it green and the red stay on. also i can't display the color blue vividly like red or green

i have noticed that:
glVertexPointer(3, %GL_FLOAT, 0, NULL)
glColorPointer(3, %GL_FLOAT, 0, NULL)

it refer to Null, but i can understand this as preventing the user from accessing the GPU memory directly, and that the moving the data to the GPU is done by glBufferData which we provide it with the address of the data. this is my own imagination and can be wrong

Uses "tbgl"

#Def %GL_GLEXT_PROTOTYPES
#Include "%app_includepath%\thinbasic_gl.inc"
#Include "%app_includepath%\thinbasic_glu.inc"
#Include "%app_includepath%\thinBasic_GLEXT.inc"
#Include "%app_includepath%\thinbasic_WGL.inc" 

Type Point3D
  x As Single
  y As Single
  z As Single
  red As Single
  green As Single
  blue As Single
End Type
  

Dim hwnd As DWord

hwnd = TBGL_CreateWindowEx("VBO example - esc to exit", 600, 600, 32, 0)
TBGL_ShowWindow 
Declare Set Address glGenBuffers, wglGetProcAddress("glGenBuffers") 
Declare Set Address glBindBuffer, wglGetProcAddress("glBindBuffer") 
Declare Set Address glBufferData, wglGetProcAddress("glBufferData") 

TBGL_ResetKeyState()

Global data(3) As Point3D 

data(1).x = 0: data(1).y = 1: data(1).z = 0
data(2).x = -1: data(2).y = -1: data(2).z = 0 
data(3).x = 1: data(3).y = -1: data(3).z = 0 
data(1).red = 1: data(1).green = 0: data(1).blue=0
data(2).red = 0: data(2).green = 1: data(2).blue=0
data(3).red = 0: data(3).green = 0: data(3).blue=1

'Create a New VBO And use the variable id To store the VBO id 
Global triangleVBO, triangleColor As DWord 

glGenBuffers(1, triangleVBO) ' //Make the New VBO active
glBindBuffer(%GL_ARRAY_BUFFER, triangleVBO)
glBufferData(%GL_ARRAY_BUFFER, SizeOf(data), VarPtr(data(1).x), %GL_STATIC_DRAW)
glBindBuffer(%GL_ARRAY_BUFFER, triangleVBO)

glGenBuffers( 1, triangleColor )
glBindBuffer(%GL_ARRAY_BUFFER, triangleColor)
glBufferData(%GL_ARRAY_BUFFER, SizeOf(data),VarPtr(data(1).red),%GL_STATIC_DRAW)

While TBGL_IsWindow(hwnd)
TBGL_ClearFrame

display
TBGL_DrawFrame
If TBGL_GetWindowKeyState( hwnd, %VK_ESCAPE) Then Exit While
Wend

TBGL_DestroyWindow

'=================================================================================

Sub display()

glEnable(%GL_DEPTH_TEST)
glDisable(%GL_CULL_FACE)
TBGL_Camera( 0, 0, 4, 0, 0, 0 )

glClear(%GL_COLOR_BUFFER_BIT Or %GL_DEPTH_BUFFER_BIT)
glClearColor(1, 1, 1, 1)

TBGL_Rotate GetTickCount/30,0,1,0

'Establish Array Contains vertices (Not normals, colours, texture coords etc)
glEnableClientState(%GL_VERTEX_ARRAY)
glEnableClientState(%GL_COLOR_ARRAY)
'Establish its 3 coordinates per vertex With zero stride In This Array; necessary here
glVertexPointer(3, %GL_FLOAT, 0, NULL)
glColorPointer(3, %GL_FLOAT, 0, NULL)
'Actually Draw the triangle, giving the Number of vertices provided
glDrawArrays(%GL_TRIANGLES, 1, 3)

glDisableClientState(%GL_COLOR_ARRAY)
glDisableClientState(%GL_VERTEX_ARRAY) 
'**************************************************

End Sub

[DirectuX]

but there is the problem of the triangle colors, it seems the color is sticky and can't be changed . as an example in line 34:
data(1).red = 1: data(1).green = 0: data(1).blue=0
if i changed red to 0 and green to 1 i can't get it green and the red stay on. also i can't display the color blue vividly like red or green

Hi Primo,

Unless I'm mistaken, changing vertex coordinates does not work either. It looks, from my point of view, that you have to specify how the vertex is stored (vertex format) in the array ( according to the Type Point3D you defined )
maybe this can help.

[primo]

Thanks DirectuX , you are right changing vertex positions not possible, i haven't noticed this. will look more about the subject. this makes the subject more complex.

[DirectuX]

Hi Primo,
According to this documentation, you may want to write it like this :

Uses "tbgl"
 
#Def %GL_GLEXT_PROTOTYPES
#Include "%app_includepath%\thinbasic_gl.inc"
#Include "%app_includepath%\thinbasic_glu.inc"
#Include "%app_includepath%\thinBasic_GLEXT.inc"
#Include "%app_includepath%\thinbasic_WGL.inc" 
 
Type Point3D

  red As Single ' Color first see line #93
  green As Single
  blue As Single
  x As Single
  y As Single
  z As Single

End Type
   
 
Dim hwnd As DWord
 
hwnd = TBGL_CreateWindowEx("VBO example - esc to exit", 600, 600, 32, 0)
TBGL_ShowWindow
Declare Set Address glGenBuffers, wglGetProcAddress("glGenBuffers") 
Declare Set Address glBindBuffer, wglGetProcAddress("glBindBuffer") 
Declare Set Address glBufferData, wglGetProcAddress("glBufferData") 
 
TBGL_ResetKeyState()
 
Global data(3) As Point3D 

data(1).x = -1
data(1).y = 0
data(1).z = 0

data(2).x = 1
data(2).y = 0
data(2).z = 0

data(3).x = 0
data(3).y = 1
data(3).z = 0

data(1).red = 1
data(1).green = 0
data(1).blue = 0

data(2).red = 0
data(2).green = 1
data(2).blue = 0

data(3).red = 0
data(3).green = 0
data(3).blue = 1
 
'Create a New VBO And use the variable id To store the VBO id 
Global triangleVBO(1) As DWord ' Doc says an array
 
glGenBuffers(1, triangleVBO) ' //Make the New VBO active
'Once is sufficient
glBindBuffer(%GL_ARRAY_BUFFER, triangleVBO(1))
glBufferData(%GL_ARRAY_BUFFER, SizeOf(data), VarPtr(data(1).red), %GL_STATIC_DRAW)

While TBGL_IsWindow(hwnd)
TBGL_ClearFrame
 
display
TBGL_DrawFrame
If TBGL_GetWindowKeyState( hwnd, %VK_ESCAPE) Then Exit While
Wend
 
TBGL_DestroyWindow
 
'=================================================================================
 
Sub display()
 
glEnable(%GL_DEPTH_TEST)
glDisable(%GL_CULL_FACE)
TBGL_Camera( 0, 0, 4, 0, 0, 0 )
 
glClear(%GL_COLOR_BUFFER_BIT Or %GL_DEPTH_BUFFER_BIT)
glClearColor(1, 1, 1, 1)
 
TBGL_Rotate GetTickCount/30,0,1,0
 
'Establish Array Contains vertices (Not normals, colours, texture coords etc)

glEnableClientState(%GL_VERTEX_ARRAY)
glEnableClientState(%GL_COLOR_ARRAY)

glInterleavedArrays(%GL_C3F_V3F, 0, null) ' using TYPE Point3D , you interleave your data

'Actually Draw the triangle, giving the Number of vertices provided
glDrawArrays(%GL_TRIANGLES, 0, 3) 'notice, this is not TB array : it starts at 0
 

glDisableClientState(%GL_VERTEX_ARRAY)
glDisableClientState(%GL_COLOR_ARRAY)
'**************************************************
 
End Sub

[primo]

Thank you very much DirectuX, your solution have kept the project small and simple.
it seems "glInterleavedArrays" is very nice function and liberating us from the trouble of mixed arrays. you have used also one buffer and glInterleavedArrays does the complex job for servicing the glDrawArrays function.
there is a big archive in https://github.com/gamedev-net/nehe-opengl
and i find lesson 45 is about VBO, there is an example using the old delphi, will install it to see the behavior of the first code
Thank You again

[primo]

albeit DirectuX approach https://www.thinbasic.com/community/...ll=1#post95195
using glInterleavedArrays with glDrawArrays is nice and short, i still thinking why my example does not work, the answer is we should use inside the main loop:

glEnableClientState(%GL_VERTEX_ARRAY)
glEnableClientState(%GL_COLOR_ARRAY)

glBindBuffer(%GL_ARRAY_BUFFER, triangleVBO)
glVertexPointer(3, %GL_FLOAT, SizeOf(Point3D), 0)

glBindBuffer(%GL_ARRAY_BUFFER, triangleColor)
glColorPointer(3, %GL_FLOAT, SizeOf(Point3D), 0)
 
glDrawArrays(%GL_TRIANGLES, 0, 3)

glDisableClientState(%GL_COLOR_ARRAY)
glDisableClientState(%GL_VERTEX_ARRAY)

now we can change dimensions and color any time and the color is okay,

Uses "tbgl"
 
#Def %GL_GLEXT_PROTOTYPES
#Include "%app_includepath%\thinbasic_gl.inc"
#Include "%app_includepath%\thinbasic_glu.inc"
#Include "%app_includepath%\thinBasic_GLEXT.inc"
#Include "%app_includepath%\thinbasic_WGL.inc" 
 
Type Point3D
  x As Single
  y As Single
  z As Single
  red As Single
  green As Single
  blue As Single
End Type
 
Dim hwnd As DWord
 
hwnd = TBGL_CreateWindowEx("glDrawArrays example - esc to exit", 600, 600, 32, 0)
TBGL_ShowWindow
TBGL_ResetKeyState()

Declare Set Address glGenBuffers,   wglGetProcAddress("glGenBuffers")   
Declare Set Address glBindBuffer,   wglGetProcAddress("glBindBuffer") 
Declare Set Address glBufferData,   wglGetProcAddress("glBufferData")  
    
Global data(3) As Point3D

data(1).x = 0: data(1).y = 1: data(1).z = 0
data(2).x = -1: data(2).y = -1: data(2).z = 0 
data(3).x = 1: data(3).y = -1: data(3).z = 0

data(1).red = 1: data(1).green = 0: data(1).blue=0
data(2).red = 0: data(2).green = 1: data(2).blue=0
data(3).red = 0: data(3).green = 0: data(3).blue=1

'msgbox 0, str$(SizeOf(Point3D))
'Create a New VBO And use the variable id To store the VBO id 
Dim triangleVBO As DWord 
Dim triangleColor As DWord

glGenBuffers(1, triangleVBO) ' //Make the New VBO active
glBindBuffer(%GL_ARRAY_BUFFER, triangleVBO)
'Upload vertex data To the video device 
glBufferData(%GL_ARRAY_BUFFER, (SizeOf(Point3D)*3), VarPtr(data(1).x), %GL_STATIC_DRAW)

glGenBuffers(2, triangleColor) 
glBindBuffer(%GL_ARRAY_BUFFER, triangleColor)
glBufferData(%GL_ARRAY_BUFFER, (SizeOf(Point3D)*3), VarPtr(data(1).red), %GL_STATIC_DRAW)

'msgbox 0, str$(SizeOf(data) )
While TBGL_IsWindow(hwnd)
TBGL_ClearFrame
 
display
TBGL_DrawFrame
If TBGL_GetWindowKeyState( hwnd, %VK_ESCAPE) Then Exit While
Wend
 
TBGL_DestroyWindow
 
'=================================================================================
 
Sub display()
glEnable(%GL_DEPTH_TEST)
glDisable(%GL_CULL_FACE)
TBGL_Camera( 0, 0, 4, 0, 0, 0 )
 
glClear(%GL_COLOR_BUFFER_BIT Or %GL_DEPTH_BUFFER_BIT) 
glClearColor(0.5, 0.5, 0.5, 0.5)
'TBGL_Rotate GetTickCount/30,0,1,0
'Draw Triangle from VBO - Do Each time Window, view point Or data changes 
glEnableClientState(%GL_VERTEX_ARRAY)
glEnableClientState(%GL_COLOR_ARRAY)

glBindBuffer(%GL_ARRAY_BUFFER, triangleVBO)
glVertexPointer(3, %GL_FLOAT, SizeOf(Point3D), 0)

glBindBuffer(%GL_ARRAY_BUFFER, triangleColor)
glColorPointer(3, %GL_FLOAT, SizeOf(Point3D), 0) 
'Actually Draw the triangle, giving the Number of vertices provided
glDrawArrays(%GL_TRIANGLES, 0, 3)
'Force display To be drawn Now
'glFlush 
 
glDisableClientState(%GL_COLOR_ARRAY)
glDisableClientState(%GL_VERTEX_ARRAY) 
'**************************************************
 
End Sub

[Petr Schreiber]

Hi Primo, DirectuX,

if you want, I could add this interleaved option to GBuffers, what do you think?


Petr

[DirectuX]

Hi Primo, DirectuX,

if you want, I could add this interleaved option to GBuffers, what do you think?


Petr

Primo, it's up to you, as I would prefer clearing tbgl issues.