testcases/phpCairo/operator-clear.php

   1 <?
   2
   3 $width = 16;
   4 $height = 16;
   5 $pad = 2;
   6
   7 function set_solid_pattern ($x, $y)
   8 {
   9     global $con;
  10     $con->set_source_rgb (1.0, 0, 0.0);
  11 }
  12
  13 function set_gradient_pattern ($x, $y)
  14 {
  15     global $con,$width,$height;
  16
  17     $pat = new CairoLinearGradient ($x, $y, $x + $width, $y + $height);
  18     $pat->add_color_stop_rgba (0.2, 1, 0, 0, 1);
  19     $pat->add_color_stop_rgba ( 0.8, 1, 0, 0, 0.0);
  20     $con->set_source ($pat);
  21
  22 }
  23
  24 function draw_mask ($x, $y)
  25 {
  26
  27     global $con,$width,$height,$sur;
  28     $wi = floor(0.9 * $width);
  29     $he = floor(0.9 * $height);
  30     $x += 0.05 * $width;
  31     $y += 0.05 * $height;
  32     //$s = new CairoImageSurface(FORMAT_ARGB32, 1, 1);
  33     $s = $sur->create_similar (
  34                                                  CONTENT_ALPHA,
  35                                                  $wi, $he);
  36     $con2 = new CairoContext($s);
  37
  38     $con2->set_source_rgb (1, 1, 1); /* white */
  39
  40     $con2->arc (0.5 * $wi, 0.5 * $he, 0.45 * $he, 0, 2 * M_PI);
  41     $con2->fill ();
  42
  43
  44     $con->mask_surface ($s, $x, $y);
  45
  46
  47 }
  48
  49 function draw_glyphs ($x, $y)
  50 {
  51
  52     global $con,$width,$height;
  53     $con->set_font_size (0.8 * $height);
  54
  55     $extents = $con->text_extents ("FG");
  56     $con->move_to (
  57                    $x + floor (($width - $extents["width"]) / 2 + 0.5) - $extents["x_bearing"],
  58                    $y + floor (($height - $extents["height"]) / 2 + 0.5) - $extents["y_bearing"]);
  59     $con->show_text ("FG");
  60 }
  61
  62 function draw_polygon ($x, $y)
  63 {
  64     global $con,$width,$height;
  65
  66     $wi = floor(0.9 * $width);
  67     $he = floor(0.9 * $height);
  68     $x += 0.05 * $width;
  69     $y += 0.05 * $height;
  70
  71     $con->new_path ();
  72     $con->move_to ($x, $y);
  73     $con->line_to ($x, $y + $he);
  74     $con->line_to ($x + $wi / 2, $y + 3 * $he / 4);
  75     $con->line_to ($x + $wi, $y + $he);
  76     $con->line_to ($x + $wi, $y);
  77     $con->line_to ($x + $wi / 2, $y + $he / 4);
  78     $con->close_path ();
  79     $con->fill ();
  80 }
  81
  82 function draw_rects ($x, $y)
  83 {
  84     global $con,$width,$height;
  85
  86     $block_width = floor(0.33 * $width + 0.5);
  87     $block_height = floor(0.33 * $height + 0.5);
  88
  89
  90     for ($i = 0; $i < 3; $i++)
  91         for ($j = 0; $j < 3; $j++)
  92             if (($i + $j) % 2 == 0)
  93                 $con->rectangle (
  94                                  $x + $block_width * $i, $y + $block_height * $j,
  95                                  $block_width,         $block_height);
  96
  97     $con->fill ();
  98 }
  99
 100 $imwidth = 2*($width+$pad) + $pad;
 101 $imheight = 4*($height+$pad) + $pad;
 102
 103 $sur = new CairoImageSurface(FORMAT_ARGB32, $imwidth, $imheight);
 104 $con = new CairoContext($sur);
 105
 106     $con->select_font_face ( "Bitstream Vera Sans",
 107                             FONT_SLANT_NORMAL,
 108                             FONT_WEIGHT_NORMAL);
 109
 110     for ($j = 0; $j < 4; $j++) {
 111         for ($i = 0; $i < 2; $i++) {
 112             $x = $i * ($width + $pad) + $pad;
 113             $y = $j * ($height + $pad) + $pad;
 114
 115             $con->save ();
 116
 117             $pat = new CairoLinearGradient ($x + $width, $y,
 118                                                    $x,         $y + $height);
 119             $pat->add_color_stop_rgba (0.2,
 120                                                0.0, 0.0, 1.0, 1.0); /* Solid blue */
 121             $pat->add_color_stop_rgba ( 0.8,
 122                                                0.0, 0.0, 1.0, 0.0); /* Transparent blue */
 123             $con->set_source ($pat);
 124
 125
 126             $con->rectangle ($x, $y, $width, $height);
 127             $con->fill_preserve ();
 128             $con->clip ();
 129
 130             $con->set_operator (OPERATOR_CLEAR);
 131             //pattern_funcs[i] ($x, $y);
 132             switch($i) {
 133                 case 0:
 134                         set_solid_pattern($x,$y);
 135                         break;
 136                 case 1:
 137                         set_gradient_pattern($x,$y);
 138                         break;
 139                 }
 140
 141         //draw_funcs[j] (cr, x, y);
 142             switch($j) {
 143                 case 0:
 144                         draw_mask($x,$y);
 145                         break;
 146                 case 1:
 147                         draw_glyphs($x,$y);
 148                         break;
 149                 case 2:
 150                         draw_polygon($x,$y);
 151                         break;
 152                 case 3:
 153                         draw_rects($x,$y);
 154                         break;
 155                 }
 156             $con->restore ();
 157         }
 158     }
 159
 160 $sur->write_to_png("operator-clear-php.png");
 161 ?>