Fix PointPlacemark orientation transformations:

Prevent tilted PointPlacemark clipping (#151).
Make rotation and tilting around specified offset point instead of image center.

Author: EMaksymenko

src/gov/nasa/worldwind/render/PointPlacemark.java

@@ -999,9 +999,26 @@ protected void doDrawOrderedRenderable(DrawContext dc, PickSupport pickCandidate
                     (byte) color.getAlpha());
             }
 
+            // Compute the scale
+            double xscale;
+            Double scale = this.getActiveAttributes().getScale();
+            if (scale != null)
+                xscale = scale * this.activeTexture.getWidth(dc);
+            else
+                xscale = this.activeTexture.getWidth(dc);
+
+            double yscale;
+            if (scale != null)
+                yscale = scale * this.activeTexture.getHeight(dc);
+            else
+                yscale = this.activeTexture.getHeight(dc);
+
+            // Calculate maximum possible depth value in case of rectangle is tilted on 90 degree and rotated on 45
+            double maxDepth = Math.max(xscale, yscale) * 1.42;
+
             // The image is drawn using a parallel projection.
             osh.pushProjectionIdentity(gl);
-            gl.glOrtho(0d, dc.getView().getViewport().width, 0d, dc.getView().getViewport().height, -1d, 1d);
+            gl.glOrtho(0d, dc.getView().getViewport().width, 0d, dc.getView().getViewport().height, -maxDepth, maxDepth);
 
             // Apply the depth buffer but don't change it (for screen-space shapes).
             if ((!dc.isDeepPickingEnabled()))
@@ -1014,52 +1031,34 @@ protected void doDrawOrderedRenderable(DrawContext dc, PickSupport pickCandidate
 
             // Adjust depth of image to bring it slightly forward
             double depth = opm.screenPoint.z - (8d * 0.00048875809d);
-            depth = depth < 0d ? 0d : (depth > 1d ? 1d : depth);
+            depth = depth < 0d ? 0d : Math.min(depth, 1d);
             gl.glDepthFunc(GL.GL_LESS);
             gl.glDepthRange(depth, depth);
 
             // The image is drawn using a translated and scaled unit quad.
-            // Translate to screen point and adjust to align hot spot.
             osh.pushModelviewIdentity(gl);
-            gl.glTranslated(opm.screenPoint.x + this.dx, opm.screenPoint.y + this.dy, 0);
 
-            // Compute the scale
-            double xscale;
-            Double scale = this.getActiveAttributes().getScale();
-            if (scale != null)
-                xscale = scale * this.activeTexture.getWidth(dc);
-            else
-                xscale = this.activeTexture.getWidth(dc);
-
-            double yscale;
-            if (scale != null)
-                yscale = scale * this.activeTexture.getHeight(dc);
-            else
-                yscale = this.activeTexture.getHeight(dc);
+            // Translate to screen point.
+            gl.glTranslated(opm.screenPoint.x, opm.screenPoint.y, 0);
 
-            Double heading = getActiveAttributes().getHeading();
+            // Apply the pitch if specified.
             Double pitch = getActiveAttributes().getPitch();
-
-            // Adjust heading to be relative to globe or screen
-            if (heading != null)
-            {
-                if (AVKey.RELATIVE_TO_GLOBE.equals(this.getActiveAttributes().getHeadingReference()))
-                    heading = dc.getView().getHeading().degrees - heading;
-                else
-                    heading = -heading;
+            if (pitch != null) {
+                gl.glRotated(pitch, 1, 0, 0);
             }
 
-            // Apply the heading and pitch if specified.
-            if (heading != null || pitch != null)
-            {
-                gl.glTranslated(xscale / 2, yscale / 2, 0);
-                if (pitch != null)
-                    gl.glRotated(pitch, 1, 0, 0);
-                if (heading != null)
-                    gl.glRotated(heading, 0, 0, 1);
-                gl.glTranslated(-xscale / 2, -yscale / 2, 0);
+            // Apply the heading if specified.
+            Double heading = getActiveAttributes().getHeading();
+            if (heading != null) {
+                // Adjust heading to be relative to globe or screen
+                heading = AVKey.RELATIVE_TO_GLOBE.equals(this.getActiveAttributes().getHeadingReference())
+                        ? dc.getView().getHeading().degrees - heading : -heading;
+                gl.glRotated(heading, 0, 0, 1);
             }
 
+            // Adjust to align hot spot.
+            gl.glTranslated(this.dx, this.dy, 0);
+
             // Scale the unit quad
             gl.glScaled(xscale, yscale, 1);
 

src/gov/nasa/worldwindx/examples/Placemarks.java

@@ -273,6 +273,7 @@ public void run()
                     // Create and assign the placemark attributes.
                     PointPlacemarkAttributes attrs = new PointPlacemarkAttributes();
                     attrs.setImage(symbolImage);
+                    attrs.setImageOffset(new Offset(0.5, 0.5, AVKey.FRACTION, AVKey.FRACTION));
                     attrs.setImageColor(new Color(1f, 1f, 1f, 1f));
                     attrs.setLabelOffset(new Offset(0.9d, 0.6d, AVKey.FRACTION, AVKey.FRACTION));
                     attrs.setScale(0.5);