Tigr-m2/modula2/examples/opengl/opengl.mod

MODULE opengl;

FROM tigr IMPORT TigrPtr, tigrWindow, tigrFree, tigrClosed, tigrClear,
                tigrUpdate, TPixelType, tigrPrint, tfont, TK_ESCAPE, tigrKeyDown,
                tigrBeginOpenGL;
FROM helper IMPORT tigrRGB, tigrRGBA;
FROM gl IMPORT glClear, glClearColor, GL_COLOR_BUFFER_BIT;

VAR
    win1, win2 : TigrPtr;

BEGIN
    win1 := tigrWindow(320, 240, "Window1", 0);
    win2 := tigrWindow(320, 240, "Window2", 0);
    WHILE (win1 # NIL) OR (win2 # NIL) DO
        IF win1 # NIL THEN
            tigrClear(win1, tigrRGB(80H, 90H, 0A0H));
            tigrPrint(win1, tfont, 120, 110, tigrRGB(0FFH, 0FFH, 0FFH),
                      "Hello, world #1.");
            tigrUpdate(win1);

            IF (tigrClosed(win1) > 0) OR (tigrKeyDown(win1, TK_ESCAPE) > 0) THEN
                tigrFree(win1);
                win1 := NIL;
            END;
        END;

        IF win2 # NIL THEN
            IF tigrBeginOpenGL(win2) # 0 THEN
                glClearColor(1.0, 0.0, 1.0, 1.0);
                glClear(GL_COLOR_BUFFER_BIT);
            END;

            tigrClear(win2, tigrRGBA(0, 0, 0, 0));
            tigrPrint(win2, tfont, 120, 110, tigrRGB(0FFH, 0FFH, 0FFH),
                      "Hello, world #2.");
            tigrUpdate(win2);

            IF (tigrClosed(win2) > 0) OR (tigrKeyDown(win2, TK_ESCAPE) > 0) THEN
                tigrFree(win2);
                win2 := NIL;
            END;
        END;
    END;
    IF win1 # NIL THEN
        tigrFree(win1);
    END;
    IF win2 # NIL THEN
        tigrFree(win2);
    END;
END opengl.