Make donut_slice_gap option work on 3D donut graph types.

Donut3DGraph.php

@@ -28,8 +28,11 @@ class Donut3DGraph extends Pie3DGraph {
 
   public function __construct($w, $h, array $settings, array $fixed_settings = [])
   {
-    // slice gap is no use on a 3D graph
-    $fs = [ 'donut_slice_gap' => 0, ];
+    $fs = [];
+    // enable flat sides when drawing a gap
+    if(isset($settings['donut_slice_gap']) && $settings['donut_slice_gap'] > 0)
+      $fs['draw_flat_sides'] = true;
+
     $fs = array_merge($fs, $fixed_settings);
     parent::__construct($w, $h, $settings, $fs);
   }

DonutGraphTrait.php

@@ -24,14 +24,10 @@
 trait DonutGraphTrait {
 
   /**
-   * Override the parent to draw doughnut slice
+   * Returns the outer and inner angle adjustments for the slice gap
    */
-  protected function getSlice($item, $angle_start, $angle_end, $radius_x,
-    $radius_y, &$attr, $single_slice, $colour_index)
+  public function getSliceGap($angle, $ratio)
   {
-    $ratio = min(0.99, max(0.01, $this->getOption('inner_radius')));
-    $angle = $angle_end - $angle_start;
-
     $gap_angle = $this->getOption('donut_slice_gap');
     $outer_a = $inner_a = 0;
     if($gap_angle > 0) {
@@ -41,7 +37,19 @@ protected function getSlice($item, $angle_start, $angle_end, $radius_x,
         $inner_a = $outer_a / $ratio;
       }
     }
+    return [$outer_a, $inner_a];
+  }
+
+  /**
+   * Override the parent to draw doughnut slice
+   */
+  protected function getSlice($item, $angle_start, $angle_end, $radius_x,
+    $radius_y, &$attr, $single_slice, $colour_index)
+  {
+    $ratio = min(0.99, max(0.01, $this->getOption('inner_radius')));
+    $angle = $angle_end - $angle_start;
 
+    list($outer_a, $inner_a) = $this->getSliceGap($angle, $ratio);
     $x_start = $y_start = $x_end = $y_end = 0;
     $angle_start += $this->s_angle;
     $angle_end += $this->s_angle;

DonutSliceEdge.php

@@ -27,6 +27,8 @@
 class DonutSliceEdge extends PieSliceEdge {
 
   protected $ratio = 1.0;
+  protected $outer_a = 0;
+  protected $inner_a = 0;
 
   /**
    * $slice is the slice details array
@@ -42,6 +44,10 @@ public function __construct(&$graph, $type, $slice, $s_angle)
     $start_angle = $slice['angle_start'] + $s_angle;
     $end_angle = $slice['angle_end'] + $s_angle;
     $ratio = min(0.99, max(0.01, $graph->getOption('inner_radius')));
+    list($outer_a, $inner_a) = $graph->getSliceGap($end_angle - $start_angle, $ratio);
+    $this->outer_a = $outer_a;
+    $this->inner_a = $inner_a;
+
     if(isset($slice['single_slice']) && $slice['single_slice'] &&
       !is_numeric($graph->end_angle)) {
 
@@ -82,6 +88,8 @@ public function __construct(&$graph, $type, $slice, $s_angle)
       // flat edge at a2
       $this->a1 = $this->a2;
       $this->ratio = $ratio;
+      $this->outer_a = -$outer_a;
+      $this->inner_a = -$inner_a;
       break;
     case 2:
       // bottom edge
@@ -123,9 +131,11 @@ public function __construct(&$graph, $type, $slice, $s_angle)
       break;
     }
 
-    $ac = ($this->a1 + $this->a2) / 2;
-    $this->x = PieSliceEdge::SCALE * cos($ac);
-    $this->y = PieSliceEdge::SCALE * sin($ac);
+    // ignore tiny curves as floating point artifacts
+    if($type > 1 && abs($this->a1 - $this->a2) < 0.0001)
+      return;
+
+    $this->setupSort();
     $this->type = $type;
   }
 
@@ -184,31 +194,30 @@ public function getInnerRatio()
    */
   protected function getFlatPath($angle, $x_centre, $y_centre, $depth)
   {
-    $rx = $this->slice['radius_x'] * cos($angle);
-    $ry = $this->slice['radius_y'] * sin($angle);
-    $x1 = $x_centre + $rx;
-    $y1 = $y_centre + $ry;
-    $x2 = $x_centre + ($rx * $this->ratio);
-    $y2 = $y_centre + ($ry * $this->ratio);
+    $rx1 = $this->slice['radius_x'] * cos($angle + $this->outer_a);
+    $ry1 = $this->slice['radius_y'] * sin($angle + $this->outer_a);
+    $rx2 = $this->slice['radius_x'] * $this->ratio * cos($angle + $this->inner_a);
+    $ry2 = $this->slice['radius_y'] * $this->ratio * sin($angle + $this->inner_a);
+    $x1 = $x_centre + $rx1;
+    $y1 = $y_centre + $ry1;
+    $x2 = $x_centre + $rx2;
+    $y2 = $y_centre + $ry2;
     return new PathData('M', $x2, $y2, 'v', $depth, 'L', $x1, $y1 + $depth,
       'v', -$depth, 'z');
-    return new PathData('M', $x_centre, $y_centre, 'v', $depth, 'L', $x1, $y1,
-      'v', -$depth, 'z');
   }
 
   /**
    * Returns the path for the curved edge
    */
   protected function getCurvedPath($x_centre, $y_centre, $depth)
   {
-    $d1 = rad2deg($this->a1);
-    $d2 = rad2deg($this->a2);
+    $a = $this->ratio < 1.0 ? $this->inner_a : $this->outer_a;
     $rx = $this->slice['radius_x'] * $this->ratio;
     $ry = $this->slice['radius_y'] * $this->ratio;
-    $x1 = $x_centre + $rx * cos($this->a1);
-    $y1 = $y_centre + $ry * sin($this->a1);
-    $x2 = $x_centre + $rx * cos($this->a2);
-    $y2 = $y_centre + $ry * sin($this->a2);
+    $x1 = $x_centre + $rx * cos($this->a1 + $a);
+    $y1 = $y_centre + $ry * sin($this->a1 + $a);
+    $x2 = $x_centre + $rx * cos($this->a2 - $a);
+    $y2 = $y_centre + $ry * sin($this->a2 - $a);
     $y2d = $y2 + $depth;
 
     $outer = 0; // edge is never > PI

PieSliceEdge.php

@@ -27,7 +27,6 @@
 class PieSliceEdge {
 
   const SCALE = 2000.0;
-  public $x;
   public $y;
   public $slice;
 
@@ -98,12 +97,22 @@ public function __construct(&$graph, $type, $slice, $s_angle)
       break;
     }
 
-    $ac = ($this->a1 + $this->a2) / 2;
-    $this->x = PieSliceEdge::SCALE * cos($ac);
-    $this->y = PieSliceEdge::SCALE * sin($ac);
+    $this->setupSort();
     $this->type = $type;
   }
 
+  /**
+   * Fills in $this->y, for sorting slices by layer depth
+   */
+  protected function setupSort()
+  {
+    if($this->a1 < M_PI_2 && $this->a2 > M_PI_2)
+      $ac = M_PI_2;
+    else
+      $ac = ($this->a1 + $this->a2) / 2;
+    $this->y = PieSliceEdge::SCALE * sin($ac);
+  }
+
   /**
    * Returns the number of edge types this class supports
    */