fpc/packages/opengl/examples/glutdemo.pp
Michaël Van Canneyt 6aa4c98cfa * PChar -> PAnsichar
2023-07-15 18:22:38 +02:00

135 lines
3.4 KiB
ObjectPascal

{
GL units for Free Pascal - GLUT demo
1999 Sebastian Guenther, sguenther@gmx.de
You may use this source as starting point for your own programs; consider it
as Public Domain.
}
{$mode objfpc}
program GLUTDemo;
uses
GL, GLU, GLUT;
const
FPCImg: array[0..4, 0..10] of Byte =
((1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1),
(1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0),
(1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0),
(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0),
(1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1));
var
counter: Integer;
const
colors: array[0..7, 0..2] of Single =
((0, 0, 0), (0, 0, 1), (0, 1, 0), (0, 1, 1),
(1, 0, 0), (1, 0, 1), (1, 1, 0), (1, 1, 1));
corners: array[0..7, 0..2] of Single =
((-1, -1, -1), (+1, -1, -1), (+1, +1, -1), (-1, +1, -1),
(-1, -1, +1), (+1, -1, +1), (+1, +1, +1), (-1, +1, +1));
procedure DrawCube;
procedure DrawSide(i1, i2, i3, i4: Integer);
begin
glColor4f (colors [i1, 0], colors [i1, 1], colors [i1, 2], 0.5);
glVertex3f(corners[i1, 0], corners[i1, 1], corners[i1, 2]);
glColor4f (colors [i2, 0], colors [i2, 1], colors [i2, 2], 0.5);
glVertex3f(corners[i2, 0], corners[i2, 1], corners[i2, 2]);
glColor4f (colors [i3, 0], colors [i3, 1], colors [i3, 2], 0.5);
glVertex3f(corners[i3, 0], corners[i3, 1], corners[i3, 2]);
glVertex3f(corners[i4, 0], corners[i4, 1], corners[i4, 2]);
end;
begin
glBegin(GL_QUADS);
DrawSide(4, 5, 6, 7); // Front
DrawSide(3, 2, 1, 0); // Back
DrawSide(2, 3, 7, 6); // Top
DrawSide(0, 1, 5, 4); // Bottom
DrawSide(4, 7, 3, 0); // Left
DrawSide(1, 2, 6, 5); // Right
glEnd;
end;
procedure DisplayWindow; cdecl;
var
x, y: Integer;
begin
Inc(counter);
glClearColor(0, 0, 0.2, 1);
glClear(GL_COLOR_BUFFER_BIT+GL_DEPTH_BUFFER_BIT);
glPushMatrix;
glTranslatef(0, 0, Sin(Single(counter) / 20.0) * 5.0 - 5.0);
glRotatef(Sin(Single(counter) / 200.0) * 720.0, 0, 1, 0);
glRotatef(counter, 0, 0, 1);
for y := 0 to 4 do
for x := 0 to 10 do
if FPCImg[y, x] > 0 then begin
glPushMatrix;
glRotatef(x * Sin(Single(counter) / 5.0), 0, 1, 0);
glRotatef(y * Sin(Single(counter) / 12.0) * 4.0, 0, 0, 1);
glTranslatef((x - 5) * 1, (2 - y) * 1, 0);
glScalef(0.4, 0.4, 0.4);
glRotatef(counter, 0.5, 1, 0);
DrawCube;
glPopMatrix;
end;
glPopMatrix;
Inc(counter);
glutSwapBuffers;
end;
procedure OnTimer(value: Integer); cdecl;
begin
glutPostRedisplay;
glutTimerFunc(20, @OnTimer, 0);
end;
begin
glutInit(@argc, argv);
glutInitDisplayMode(GLUT_RGB or GLUT_DOUBLE or GLUT_DEPTH);
glutCreateWindow('Free Pascal GLUT demo');
glutDisplayFunc(@DisplayWindow);
glutTimerFunc(20, @OnTimer, 0);
WriteLn;
WriteLn('GL info:');
WriteLn(' Vendor: ', PAnsiChar(glGetString(GL_VENDOR)));
WriteLn(' Renderer: ', PAnsiChar(glGetString(GL_RENDERER)));
WriteLn(' Version: ', PAnsiChar(glGetString(GL_VERSION)));
WriteLn(' Extensions: ', PAnsiChar(glGetString(GL_EXTENSIONS)));
// Enable backface culling
glEnable(GL_CULL_FACE);
// Set up depth buffer
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
// Set up projection matrix
glMatrixMode(GL_PROJECTION);
glLoadIdentity;
gluPerspective(90, 1.3, 0.1, 100);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity;
glTranslatef(0, 0, -5.5);
WriteLn('Starting...');
glutMainLoop;
end.