Re: Best way to put an array-based pixmap on a screen?

[reinert <reinkor@gmail.com>]

In case it could be useful, here is a simple test program using GLOBE_3D (texture). I just started to use GLOBE_3D for fast (interactive) video-like rendering (programming in Ada).

reinert
https://korsnesbiocomputing.no/


with Text_IO; use Text_IO;
with GL,  GLUT.Devices;
use  GL,  GLUT.Devices;

procedure a1 is

  package Flt_Io is new Text_IO.Float_Io   (Float);
  package Int_Io is new Text_IO.Integer_Io (Integer);
  use Flt_Io,Int_Io;

  GLUT_Problem: exception;
  use GLUT;

  texDat : array (1..64) of aliased gl.ushort; 
  texDat_Ptr : constant pointer := to_Pointer(texDat(texDat'First)'unchecked_access);

  tex    : aliased GL.uint;
  tex_Ptr : constant GL.uintPtr := tex'unchecked_access; 
 
  n,k : Integer := 1;

begin

    glut.Init;
    glut.SetOption(GLUT.ACTION_ON_WINDOW_CLOSE, GLUT.ACTION_GLUTMAINLOOP_RETURNS);
    glut.InitDisplayMode( GLUT.DOUBLE or GLUT.RGB or GLUT.DEPTH );
    glut.InitWindowSize(800,600);
    glut.InitWindowPosition(1, 1);
    if glut.CreateWindow( "Tittel A" ) = 0 then
      raise GLUT_Problem;
    end if;
    glut.Devices.Initialize;

    n := texDat'First;
    for i in 1..8 loop
        for j in 1..8 loop
            k := (if i = j then 1 else 0);
            k := (if (i + j) mod 2 = 0 then 1 else 0);
            texDat(n) := gl.ushort(k*100 + 100);
            n := n + 1;
        end loop;
    end loop;

    gl.GenTextures(1, tex_Ptr);
    gl.BindTexture(GL.TEXTURE_2D, tex);

    gl.TexParameter(GL.TEXTURE_2D, GL.TEXTURE_MIN_FILTER, GL.NEAREST);
    gl.TexParameter(GL.TEXTURE_2D, GL.TEXTURE_MAG_FILTER, GL.NEAREST);

    gl.TexImage2D(GL.TEXTURE_2D, 0, GL.LUMINANCE, 8, 8, 0, GL.LUMINANCE_ALPHA, GL_UNSIGNED_BYTE, texDat_Ptr);

    gl.BindTexture(GL.TEXTURE_2D, 0);
    gl.MatrixMode(GL.PROJECTION);
    gl.Ortho(0.0, 800.0, 0.0, 600.0, -1.0, 1.0);
    gl.MatrixMode(GL.MODELVIEW);
    gl.ClearColor(1.0, 1.0, 1.0, 0.0); 

    gl.Clear(GL.COLOR_BUFFER_BIT);

    gl.BindTexture(GL.TEXTURE_2D, tex);
    gl.Enable(GL.TEXTURE_2D);

    gl.Color(1.0, 1.0, 1.0, 1.0);
    gl_Begin(QUADS);
      gl.TexCoord(0.0, 0.0); gl.Vertex(100, 100);
      gl.TexCoord(0.0, 1.0); gl.Vertex(100, 500);
      gl.TexCoord(1.0, 1.0); gl.Vertex(500, 500);
      gl.TexCoord(1.0, 0.0); gl.Vertex(500, 100);
    gl_End;

    gl.Disable(GL.TEXTURE_2D);
    gl.BindTexture(GL.TEXTURE_2D, 0);
    gl.Flush;
    glut.SwapBuffers;

    Delay 10.0;

end a1;