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Text File  |  2002-10-03  |  11.6 KB  |  202 lines
  1.  
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  4. ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrSSSSGGGGIIIISSSS((((3333GGGG))))      OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee      ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrSSSSGGGGIIIISSSS((((3333GGGG))))
  5.  
  6.  
  7.  
  8. NNNNAAAAMMMMEEEE
  9.      ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrffffSSSSGGGGIIIISSSS,,,, ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrffffvvvvSSSSGGGGIIIISSSS - set point parameters
  10.  
  11.  
  12. FFFFOOOORRRRTTTTRRRRAAAANNNN SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
  13.      SUBROUTINE ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrffffSSSSGGGGIIIISSSS( INTEGER*4 _p_n_a_m_e,
  14.                                         REAL*4 _p_a_r_a_m )
  15.  
  16.  
  17.  
  18.  
  19. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  20.      _p_n_a_m_e   The symbolic name of a point parameter.  One of
  21.              GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____MMMMIIIINNNN____SSSSGGGGIIIISSSS or GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____MMMMAAAAXXXX____SSSSGGGGIIIISSSS or
  22.              GGGGLLLL____PPPPOOOOIIIINNNNTTTT____FFFFAAAADDDDEEEE____TTTTHHHHRRRREEEESSSSHHHHOOOOLLLLDDDD____SSSSIIIIZZZZEEEE____SSSSGGGGIIIISSSS.
  23.  
  24.      _p_a_r_a_m   The parameter value.
  25.  
  26.  
  27.  
  28. FFFFOOOORRRRTTTTRRRRAAAANNNN SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
  29.      SUBROUTINE ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrffffvvvvSSSSGGGGIIIISSSS( INTEGER*4 _p_n_a_m_e,
  30.                                          CHARACTER*8 _p_a_r_a_m_s )
  31.  
  32.  
  33. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  34.      _p_n_a_m_e
  35.           The symbolic name of a point parameter.  One of
  36.           GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____MMMMIIIINNNN____SSSSGGGGIIIISSSS or GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____MMMMAAAAXXXX____SSSSGGGGIIIISSSS or
  37.           GGGGLLLL____PPPPOOOOIIIINNNNTTTT____FFFFAAAADDDDEEEE____TTTTHHHHRRRREEEESSSSHHHHOOOOLLLLDDDD____SSSSIIIIZZZZEEEE____SSSSGGGGIIIISSSS or GGGGLLLL____DDDDIIIISSSSTTTTAAAANNNNCCCCEEEE____AAAATTTTTTTTEEEENNNNUUUUAAAATTTTIIIIOOOONNNN____SSSSGGGGIIIISSSS.
  38.  
  39.      _p_a_r_a_m_s
  40.           A pointer to an array where the values of the parameters are stored.
  41.  
  42.  
  43. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  44.      ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrSSSSGGGGIIIISSSS is part of the SSSSGGGGIIIISSSS____ppppooooiiiinnnntttt____ppppaaaarrrraaaammmmeeeetttteeeerrrrssss extension. It
  45.      supports additional geometric characteristics of points. It allows the
  46.      size of a point to decrease, as the the distance of the point from the
  47.      eye increases. It provides control over the mapping from the point size
  48.      to the raster point area and point transparency, in order to increase the
  49.      dynamic range of the raster brightness of points.
  50.  
  51.      The derived point size is defined to be the _s_i_z_e provided with
  52.      ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee modulated with a distance attenuation factor.
  53.  
  54.      The distance attenuation function coefficients, namely a, b, and c in:
  55.  
  56.           dist_atten(d) = 1 / (a + b x d + c x d^2)
  57.  
  58.      are defined by the GGGGLLLL____DDDDIIIISSSSTTTTAAAANNNNCCCCEEEE____AAAATTTTTTTTEEEENNNNUUUUAAAATTTTIIIIOOOONNNN____SSSSGGGGIIIISSSS parameters.  By default a
  59.      = 1, b = 0, and c = 0.
  60.  
  61.      Let _s_i_z_e be the point size provided with ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee, let _d_i_s_t be the
  62.      distance of the point from the eye, and let _t_h_r_e_s_h_o_l_d be the threshold
  63.  
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  65.  
  66.                                                                         PPPPaaaaggggeeee 1111
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  73. ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrSSSSGGGGIIIISSSS((((3333GGGG))))      OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee      ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrSSSSGGGGIIIISSSS((((3333GGGG))))
  74.  
  75.  
  76.  
  77.      size defined by the GGGGLLLL____PPPPOOOOIIIINNNNTTTT____FFFFAAAADDDDEEEE____TTTTHHHHRRRREEEESSSSHHHHOOOOLLLLDDDD____SSSSIIIIZZZZEEEE parameter. The derived
  78.      point size is given by:
  79.  
  80.           derived_size = _s_i_z_e x sqrt(dist_atten(_d_i_s_t))
  81.  
  82.      Note that when default values are used, the above formula reduces to:
  83.  
  84.           derived_size = _s_i_z_e
  85.  
  86.      If the derived point size is larger than the upper bound defined by the
  87.      GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____MMMMAAAAXXXX____SSSSGGGGIIIISSSS parameter, or smaller than the lower bound defined
  88.      by the GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____MMMMIIIINNNN____SSSSGGGGIIIISSSS parameter, the derived size is clamped to
  89.      the upper and lower bounds respectively.
  90.  
  91.      If the derived point size is larger than the threshold size defined by
  92.      the GGGGLLLL____PPPPOOOOIIIINNNNTTTT____FFFFAAAADDDDEEEE____TTTTHHHHRRRREEEESSSSHHHHOOOOLLLLDDDD____SSSSIIIIZZZZEEEE____SSSSGGGGIIIISSSS parameter, the derived point size
  93.      is used as the diameter of the rasterized point, and the alpha component
  94.      is intact.  Otherwise, the threshold size is set to be the diameter of
  95.      the rasterized point, while the alpha component is modulated accordingly,
  96.      to compensate for the larger area.
  97.  
  98.      The diameter of the rasterized point is given by:
  99.  
  100.  
  101.                      derived_size                 derived_size >= _t_h_r_e_s_h_o_l_d
  102.           diameter =
  103.                      _t_h_r_e_s_h_o_l_d                                    Otherwise
  104.  
  105.      The alpha component of the rasterized point is given by:
  106.  
  107.  
  108.                   _a_l_p_h_a__i_n                        derived_size >= _t_h_r_e_s_h_o_l_d
  109.           alpha =
  110.                   _a_l_p_h_a__i_n x (derived_size / _t_h_r_e_s_h_o_l_d)^2         Otherwise
  111.  
  112.      where _a_l_p_h_a__i_n is point alpha possibly modified by lighting.
  113.  
  114.  
  115. NNNNOOOOTTTTEEEESSSS
  116.      The parameter GGGGLLLL____PPPPOOOOIIIINNNNTTTT____FFFFAAAADDDDEEEE____TTTTHHHHRRRREEEESSSSHHHHOOOOLLLLDDDD____SSSSIIIIZZZZEEEE____SSSSGGGGIIIISSSS has no effect on non
  117.      multisampled points. All other parameters affect non multisampled points
  118.      as well as multisampled points,
  119.  
  120.      The threshold defined by GGGGLLLL____PPPPOOOOIIIINNNNTTTT____FFFFAAAADDDDEEEE____TTTTHHHHRRRREEEESSSSHHHHOOOOLLLLDDDD____SSSSIIIIZZZZEEEE____SSSSGGGGIIIISSSS is not clamped
  121.      to the minimum or maximum point sizes.
  122.  
  123.  
  124. EEEERRRRRRRROOOORRRRSSSS
  125.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____EEEENNNNUUUUMMMM is generated if _p_n_a_m_e is not one of the allowable values.
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  131.  
  132.                                                                         PPPPaaaaggggeeee 2222
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  138.  
  139. ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrSSSSGGGGIIIISSSS((((3333GGGG))))      OOOOppppeeeennnnGGGGLLLL RRRReeeeffffeeeerrrreeeennnncccceeee      ffffggggllllPPPPooooiiiinnnnttttPPPPaaaarrrraaaammmmeeeetttteeeerrrrSSSSGGGGIIIISSSS((((3333GGGG))))
  140.  
  141.  
  142.  
  143.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____VVVVAAAALLLLUUUUEEEE is generated if _p_n_a_m_e is GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____MMMMIIIINNNN____SSSSGGGGIIIISSSS or
  144.      GGGGLLLL____PPPPOOOOIIIINNNNTTTT____FFFFAAAADDDDEEEE____TTTTHHHHRRRREEEESSSSHHHHOOOOLLLLDDDD____SSSSIIIIZZZZEEEE____SSSSGGGGIIIISSSS, and _p_a_r_a_m_s is less than zero.
  145.      GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____VVVVAAAALLLLUUUUEEEE is generated if _p_n_a_m_e is GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____MMMMAAAAXXXX____SSSSGGGGIIIISSSS and
  146.      _p_a_r_a_m_s is less than or equal to zero.
  147.  
  148.  
  149. AAAASSSSSSSSOOOOCCCCIIIIAAAATTTTEEEEDDDD GGGGEEEETTTTSSSS
  150.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____MMMMIIIINNNN____SSSSGGGGIIIISSSS
  151.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____PPPPOOOOIIIINNNNTTTT____SSSSIIIIZZZZEEEE____MMMMAAAAXXXX____SSSSGGGGIIIISSSS
  152.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____PPPPOOOOIIIINNNNTTTT____FFFFAAAADDDDEEEE____TTTTHHHHRRRREEEESSSSHHHHOOOOLLLLDDDD____SSSSIIIIZZZZEEEE____SSSSGGGGIIIISSSS
  153.      ffffggggllllGGGGeeeetttt with argument GGGGLLLL____DDDDIIIISSSSTTTTAAAANNNNCCCCEEEE____AAAATTTTTTTTEEEENNNNUUUUAAAATTTTIIIIOOOONNNN____SSSSGGGGIIIISSSS
  154.  
  155.  
  156.  
  157.  
  158. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  159.      ffffggggllllPPPPooooiiiinnnnttttSSSSiiiizzzzeeee.
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  198.                                                                         PPPPaaaaggggeeee 3333
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  202.