PureBasic Forums - English

Posted: **Sun Feb 08, 2009 3:18 pm**

If i use the opengl subsystem , and i call openscreen() function , the screen is an sdl screen ?

Posted: **Sun Feb 08, 2009 5:59 pm**

yes, SDL provides a way to interface with OpenGL by providing a display surface.

Posted: **Sun Feb 08, 2009 9:51 pm**

Ok , because i have bug when i use my lib ( written in c++ )

For example :

I create the screen with OpenScreen() and opengl subsystem
and after i create with my lib a simple texture

like this :

Code: Select all

GLubyte Texture[16] =
{
0,0,0,0, 0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF, 0,0,0,0
};


   glEnable(GL_TEXTURE_2D);
    glEnable(GL_DEPTH_TEST);

    glGenTextures(1,&gltexture);



 	glBindTexture(GL_TEXTURE_2D,gltexture);  	//Sélectionne ce n°
		 glTexImage2D (
					GL_TEXTURE_2D,
					0, 	//Mipmap
					GL_RGBA,
					2,
					2,
					0, //Border
					GL_RGBA, 	//Format : RGBA
					GL_UNSIGNED_BYTE,
					Texture
                  );

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,  GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,  GL_NEAREST);

	glDisable(GL_DEPTH_TEST);
	glDisable(GL_TEXTURE_2D);

and after , in the main code i call the display func
like this :

Code: Select all

void Draw()
{


GlEnable & Glbind...
 	
	glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); 	//Efface le framebuffer et le depthbuffer
glMatrixMode(GL_MODELVIEW); 	//Un petit gluLookAt()...
glLoadIdentity();
gluLookAt(3,2,3,0,0,0,0,1,0);
glBegin(GL_QUADS); 	//Et c'est parti pour le cube !

    glTexCoord2i(0,0);glVertex3i(-1,-1,-1);
    glTexCoord2i(1,0);glVertex3i(+1,-1,-1);
    glTexCoord2i(1,1);glVertex3i(+1,+1,-1);
    glTexCoord2i(0,1);glVertex3i(-1,+1,-1);

	//1 face

    glTexCoord2i(0,0);glVertex3i(-1,-1,+1);
    glTexCoord2i(1,0);glVertex3i(+1,-1,+1);
    glTexCoord2i(1,1);glVertex3i(+1,+1,+1);
    glTexCoord2i(0,1);glVertex3i(-1,+1,+1);

	//2 faces

    glTexCoord2i(0,0);glVertex3i(+1,-1,-1);
    glTexCoord2i(1,0);glVertex3i(+1,-1,+1);
    glTexCoord2i(1,1);glVertex3i(+1,+1,+1);
    glTexCoord2i(0,1);glVertex3i(+1,+1,-1);

	//3 faces

    glTexCoord2i(0,0);glVertex3i(-1,-1,-1);
    glTexCoord2i(1,0);glVertex3i(-1,-1,+1);
    glTexCoord2i(1,1);glVertex3i(-1,+1,+1);
    glTexCoord2i(0,1);glVertex3i(-1,+1,-1);

	//4 faces

    glTexCoord2i(1,0);glVertex3i(-1,+1,-1);
    glTexCoord2i(1,1);glVertex3i(+1,+1,-1);
    glTexCoord2i(0,1);glVertex3i(+1,+1,+1);
    glTexCoord2i(0,0);glVertex3i(-1,+1,+1);

	//5 faces

    glTexCoord2i(1,0);glVertex3i(-1,-1,+1);
    glTexCoord2i(1,1);glVertex3i(+1,-1,+1);
    glTexCoord2i(0,1);glVertex3i(+1,-1,-1);
    glTexCoord2i(0,0);glVertex3i(-1,-1,-1);

	//6 faces
glEnd(); 	
}

The texture appear white !
The solution for me is the SDL api for see correctly the texture.

it's work correctly with :

Code: Select all

ImportC "-lsgui"
	sgui_initialize.i()
  sgui_sys_ortho2dstart(gui.i)
	sgui_sys_ortho2dend(gui.i)
	sgui_sys_createcontext.i( x.i, y.i, width.i, height.i)
	sgui_sys_renderingcontext(gui.i , context.i)
	
	GetError_()
	
EndImport

	OpenConsole()

InitSprite() : InitKeyboard()
; OpenScreen(800,600,32,"")
SDL_Init_(#SDL_INIT_VIDEO)
screen = SDL_SetVideoMode_(800, 600, 32, #SDL_OPENGL);

 MyGui = sgui_initialize()

context = sgui_sys_createcontext(100,100,128,256)

Repeat

  Error = GetError_()
  If Error
  Debug Error
  End
  EndIf 


; ExamineKeyboard()
 sgui_sys_ortho2dstart(MyGui)
 sgui_sys_renderingcontext(MyGui,context)
 	sgui_sys_ortho2dend(MyGui)
 
SDL_GL_SwapBuffers_();

ForEver

I wan't to use OpenScreen() & co , not SDL api :/

PureBasic Forums - English

[4.3]subsystem opengl

[4.3]subsystem opengl