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                                           314
CHAPTER 4                                                                  Graphics



  11 0 obj                                                % First subfunction
     << /FunctionType 2
         /Domain [ 0.0 1.0 ]
         /C0 [ 0.929 0.357 1.000 0.298 ]
         /C1 [ 0.631 0.278 1.000 0.027 ]
         /N 1.048
     >>
  endobj

  12 0 obj                                                % Second subfunction
     << /FunctionType 2
         /Domain [ 0.0 1.0 ]
         /C0 [ 0.929 0.357 1.000 0.298 ]
         /C1 [ 0.941 0.400 1.000 0.102 ]
         /N 1.374
     >>
  endobj

Example 4.26

  316.789 140.311 m                                      % Move to start of leaf
  303.222 146.388 282.966 136.518 279.122 121.983 c      % Curved segment
  277.322 120.182 l                                      % Straight line
  285.125 122.688 291.441 121.716 298.156 119.386 c      % Curved segment
  336.448 119.386 l                                      % Straight line
  331.072 128.643 323.346 137.376 316.789 140.311 c      % Curved segment
  W n                                                    % Set clipping path
  q                                                      % Save graphics state
     27.7843 0.0000 0.0000 −27.7843 310.2461 121.1521 cm        % Set matrix
     /Sh1 sh                                                    % Paint shading
  Q                                                      % Restore graphics state


Type 4 Shadings (Free-Form Gouraud-Shaded Triangle Meshes)

Type 4 shadings (free-form Gouraud-shaded triangle meshes) are commonly
used to represent complex colored and shaded three-dimensional shapes. The
area to be shaded is defined by a path composed entirely of triangles. The color at
each vertex of the triangles is specified, and a technique known as Gouraud
interpolation is used to color the interiors. The interpolation functions defining
the shading may be linear or nonlinear. Table 4.32 shows the entries specific to
this type of shading dictionary, in addition to those common to all shading dic-
tionaries (Table 4.28) and stream dictionaries (Table 3.4 on page 62).

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