Changeset 127435f in git

Timestamp:

04/07/19 03:15:27 (4 months ago)

Author:

Olly Betts <olly@…>

Branches:

master

Children:

d034033

Parents:

ead0c22

git-author:

Olly Betts <olly@…> (04/07/19 03:04:03)

git-committer:

Olly Betts <olly@…> (04/07/19 03:15:27)

Message:

Draw the measuring line ring with an even shape

Previously the exact shape of the ring varied slightly depending on
the exact coordinates, which could be visually distracting once you
noticed it.

Files:

• doc/TODO.htm (modified) (1 diff)
• src/gla-gl.cc (modified) (1 diff)

doc/TODO.htm

@@ -50 +50 @@
 with a copy from the back buffer and redraw it in the new position without a
 re-render.
-
-<li>Round the measuring line coords so the ring is a nice shape?  Or just
-antialias the ring, "there" blob and line?
 
 <li>Process all pending input before rerendering to improve responsiveness.

src/gla-gl.cc

@@ -1417 +1417 @@
 void GLACanvas::DrawRing(glaCoord x, glaCoord y)
 {
-    // Draw an unfilled circle
-    const Double radius = 4;
-    assert(m_Quadric);
-    glMatrixMode(GL_MODELVIEW);
-    CHECK_GL_ERROR("DrawRing", "glMatrixMode");
-    glPushMatrix();
-    CHECK_GL_ERROR("DrawRing", "glPushMatrix");
-    glTranslated(x, y, 0.0);
-    CHECK_GL_ERROR("DrawRing", "glTranslated");
-    gluDisk(m_Quadric, radius - 1.0, radius, 12, 1);
-    CHECK_GL_ERROR("DrawRing", "gluDisk");
-    glPopMatrix();
-    CHECK_GL_ERROR("DrawRing", "glPopMatrix");
+    // Draw an unfilled circle of radius 4
+
+    // Round to integers to get an even ring.
+    x = rint(x);
+    y = rint(y);
+
+    glBegin(GL_LINE_LOOP);
+    PlaceIndicatorVertex(x + 3.5, y - 1.5);
+    PlaceIndicatorVertex(x + 1.5, y - 3.5);
+    PlaceIndicatorVertex(x - 1.5, y - 3.5);
+    PlaceIndicatorVertex(x - 3.5, y - 1.5);
+    PlaceIndicatorVertex(x - 3.5, y + 1.5);
+    PlaceIndicatorVertex(x - 1.5, y + 3.5);
+    PlaceIndicatorVertex(x + 1.5, y + 3.5);
+    PlaceIndicatorVertex(x + 3.5, y + 1.5);
+    glEnd();
+    CHECK_GL_ERROR("DrawRing", "glEnd GL_LINE_LOOP");
 }