From: Jim Procter <j.procter@dundee.ac.uk>
Date: Wed, 18 Aug 2021 15:40:27 +0000 (+0100)
Subject: JAL-2349 - deobfuscate the renderer and fix it .. work in progress
X-Git-Tag: Release_2_11_3_0~23^2~60^2~4
X-Git-Url: http://source.jalview.org/gitweb/?a=commitdiff_plain;h=b73daacd5e820b7c0bc3d693c597903c67836bb5;p=jalview.git

JAL-2349 - deobfuscate the renderer and fix it .. work in progress
---

diff --git a/src/jalview/renderer/ContactMapRenderer.java b/src/jalview/renderer/ContactMapRenderer.java
index 7413e65..c9198ed 100644
--- a/src/jalview/renderer/ContactMapRenderer.java
+++ b/src/jalview/renderer/ContactMapRenderer.java
@@ -69,24 +69,28 @@ public class ContactMapRenderer implements AnnotationRowRendererI
       {
         return;
       }
-
-      // cell height to render
-      double scale = (_aa.graphHeight < contacts.getContactHeight()) ? 1
-              : ((double) _aa.graphHeight)
-                      / (double) contacts.getContactHeight();
+      int contact_height = contacts.getContactHeight();
+      // fractional pixel height to render each contact cell
+      double pixels_per_contact = ((double) _aa.graphHeight)
+                      / (double) contact_height;
+      // fractional number of contacts covering each pixel
+      double contacts_per_pixel = 1d/pixels_per_contact;
+      // number of contacts to render at a time
+      int step = (pixels_per_contact<1) ? (int) Math.floor(contacts_per_pixel) : (int) Math.ceil(pixels_per_contact);
+      
+      int pixels_step = (int) Math.ceil(step*pixels_per_contact);
       int cstart, cend = -1;
-      for (int ht = y2, eht = y2 - _aa.graphHeight; ht >= eht; ht -= scale)
+      for (int ht = y2, eht = y2 - _aa.graphHeight; ht >= eht; ht -= pixels_step)
       {
         cstart = cend + 1;
-        cend = Math.max(cstart + 1, contacts.getContactHeight()
-                * ((ht - y2) / _aa.graphHeight));
+        cend = (int) Math.min(contact_height, cstart + step);
         // TODO show maximum colour for range - sort of done
         // also need a 'getMaxPosForRange(start,end)'
         g.setColor(getColorForRange(min, max, contacts, cstart, cend));
 
-        if (scale > 1)
+        if (pixels_step>1)
         {
-          g.fillRect(x * charWidth, ht, charWidth, 1 + (int) scale);
+          g.fillRect(x * charWidth, ht, charWidth, 1 + (int) pixels_step);
         }
         else
         {