3dmaths.inc

著名的游戏开发库Allegro4.2.0 for DELPHI

{*         ______   ___    ___
 *        /\  _  \ /\_ \  /\_ \
 *        \ \ \L\ \\//\ \ \//\ \      __     __   _ __   ___
 *         \ \  __ \ \ \ \  \ \ \   /'__`\ /'_ `\/\`'__\/ __`\
 *          \ \ \/\ \ \_\ \_ \_\ \_/\  __//\ \L\ \ \ \//\ \L\ \
 *           \ \_\ \_\/\____\/\____\ \____\ \____ \ \_\\ \____/
 *            \/_/\/_/\/____/\/____/\/____/\/___L\ \/_/ \/___/
 *                                           /\____/
 *                                           \_/__/
 *
 *      3D maths inline functions (generic C).
 *
 *      By Shawn Hargreaves.
 *
 *      See readme.txt for copyright information.
 *}
{$IFDEF ALLEGRO_INTERFACE}
function dot_product(x1, y1, z1, x2, y2, z2: fixed): fixed;
function dot_product_f(x1, y1, z1, x2, y2, z2: single): single;
procedure persp_project(x, y, z: fixed; var xout, yout: fixed);
procedure persp_project_f(x, y, z: single; var xout, yout: single);
{$ENDIF ALLEGRO_INTERFACE}
{$IFDEF ALLEGRO_IMPLEMENTATION}
function dot_product(x1, y1, z1, x2, y2, z2: fixed): fixed;
begin
  Result := fixmul(x1, x2) + fixmul(y1, y2) + fixmul(z1, z2);
end;

function dot_product_f(x1, y1, z1, x2, y2, z2: single): single;
begin
  Result := (x1 * x2) + (y1 * y2) + (z1 * z2);
end;        

procedure persp_project(x, y, z: fixed; var xout, yout: fixed);
begin
  xout := fixmul(fixdiv(x, z), _persp_xscale^) + _persp_xoffset^;
  yout := fixmul(fixdiv(y, z), _persp_yscale^) + _persp_yoffset^;
end;

procedure persp_project_f(x, y, z: single; var xout, yout: single);
var
  z1: single;
begin
  z1 := 1.0 / z;
  xout := ((x * z1) * _persp_xscale_f^) + _persp_xoffset_f^;
  yout := ((y * z1) * _persp_yscale_f^) + _persp_yoffset_f^;
end;
{$ENDIF ALLEGRO_IMPLEMENTATION}
{$IFDEF ALLEGRO_LOADVARIABLE}
{$ENDIF ALLEGRO_LOADVARIABLE}