visualizer: don't push synthetic coordinates through the map projection

Once a GeoMapCanvasVisualizer attaches an equirectangular map projection to the
shared canvas projection, computeCanvasPoint() reinterprets every coordinate as
geographic (ECEF). The scene axis visualizer and the medium heat-map fed it
synthetic basis vectors (Coord::ZERO, unit axes), which then mapped to garbage.
Add applyMapProjection parameter (default true) to computeCanvasPoint()
(for affine transform only) and use it at those synthetic-coordinate sites.

Author: rhornig

src/inet/common/geometry/common/CanvasProjection.cc

@@ -20,16 +20,17 @@ CanvasProjection::~CanvasProjection()
 {
 }
 
-cFigure::Point CanvasProjection::computeCanvasPoint(const Coord& point) const
+cFigure::Point CanvasProjection::computeCanvasPoint(const Coord& point, bool applyMapProjection) const
 {
     double depth;
-    return computeCanvasPoint(point, depth);
+    return computeCanvasPoint(point, depth, applyMapProjection);
 }
 
-cFigure::Point CanvasProjection::computeCanvasPoint(const Coord& point, double& depth) const
+cFigure::Point CanvasProjection::computeCanvasPoint(const Coord& point, double& depth, bool applyMapProjection) const
 {
-    // optional first projection stage (e.g. equirectangular), then the affine view transform
-    Coord projected = mapProjection ? mapProjection->applyForward(point) : point;
+    // optional first projection stage (e.g. equirectangular), then the affine view transform; pass
+    // applyMapProjection = false to skip the first stage (see the header)
+    Coord projected = (applyMapProjection && mapProjection) ? mapProjection->applyForward(point) : point;
     Coord rotatedPoint = rotation.rotateVector(projected);
     depth = rotatedPoint.z;
     return cFigure::Point(rotatedPoint.x * scale.x + translation.x, rotatedPoint.y * scale.y + translation.y);

src/inet/common/geometry/common/CanvasProjection.h

@@ -67,8 +67,12 @@ class INET_API CanvasProjection
     const cFigure::Point& getTranslation() const { return translation; }
     void setTranslation(const cFigure::Point& translation) { this->translation = translation; }
 
-    cFigure::Point computeCanvasPoint(const Coord& point) const;
-    cFigure::Point computeCanvasPoint(const Coord& point, double& depth) const;
+    // Pass applyMapProjection = false to skip the optional map-projection first stage and run the affine
+    // view transform only. For callers that pass synthetic scene coordinates (axis basis vectors, a
+    // heat-map grid origin) which must not be reinterpreted as geographic positions when a map projection
+    // is attached to this shared projection.
+    cFigure::Point computeCanvasPoint(const Coord& point, bool applyMapProjection = true) const;
+    cFigure::Point computeCanvasPoint(const Coord& point, double& depth, bool applyMapProjection = true) const;
     Coord computeCanvasPointInverse(const cFigure::Point& point, double depth) const;
 
     // Projects a direction (tangent) vector anchored at the given scene point to a canvas-space vector.

src/inet/visualizer/canvas/physicallayer/MediumCanvasVisualizer.cc

@@ -71,9 +71,11 @@ void MediumCanvasVisualizer::initialize(int stage)
             const IMediumLimitCache *mediumLimitCache = radioMedium->getMediumLimitCache();
             Coord min = mediumLimitCache->getMinConstraintArea();
             Coord max = mediumLimitCache->getMaxConstraintArea();
-            cFigure::Point o = canvasProjection->computeCanvasPoint(Coord::ZERO);
-            cFigure::Point x = canvasProjection->computeCanvasPoint(Coord(1, 0, 0));
-            cFigure::Point y = canvasProjection->computeCanvasPoint(Coord(0, 1, 0));
+            // synthetic basis vectors for the heat-map affine; use the affine-only transform so they are
+            // not reinterpreted as geographic positions when a map projection is attached to the canvas
+            cFigure::Point o = canvasProjection->computeCanvasPoint(Coord::ZERO, false);
+            cFigure::Point x = canvasProjection->computeCanvasPoint(Coord(1, 0, 0), false);
+            cFigure::Point y = canvasProjection->computeCanvasPoint(Coord(0, 1, 0), false);
             double t1 = o.x;
             double t2 = o.y;
             double a = x.x - t1;

src/inet/visualizer/canvas/scene/SceneCanvasVisualizer.cc

@@ -87,15 +87,15 @@ void SceneCanvasVisualizer::refreshAxis(double axisLength)
     auto xLabel = check_and_cast<cLabelFigure *>(axisLayer->getFigure(3));
     auto yLabel = check_and_cast<cLabelFigure *>(axisLayer->getFigure(4));
     auto zLabel = check_and_cast<cLabelFigure *>(axisLayer->getFigure(5));
-    xAxis->setStart(canvasProjection->computeCanvasPoint(Coord::ZERO));
-    yAxis->setStart(canvasProjection->computeCanvasPoint(Coord::ZERO));
-    zAxis->setStart(canvasProjection->computeCanvasPoint(Coord::ZERO));
-    xAxis->setEnd(canvasProjection->computeCanvasPoint(Coord(axisLength, 0, 0)));
-    yAxis->setEnd(canvasProjection->computeCanvasPoint(Coord(0, axisLength, 0)));
-    zAxis->setEnd(canvasProjection->computeCanvasPoint(Coord(0, 0, axisLength)));
-    xLabel->setPosition(canvasProjection->computeCanvasPoint(Coord(axisLength, 0, 0)));
-    yLabel->setPosition(canvasProjection->computeCanvasPoint(Coord(0, axisLength, 0)));
-    zLabel->setPosition(canvasProjection->computeCanvasPoint(Coord(0, 0, axisLength)));
+    xAxis->setStart(canvasProjection->computeCanvasPoint(Coord::ZERO, false));
+    yAxis->setStart(canvasProjection->computeCanvasPoint(Coord::ZERO, false));
+    zAxis->setStart(canvasProjection->computeCanvasPoint(Coord::ZERO, false));
+    xAxis->setEnd(canvasProjection->computeCanvasPoint(Coord(axisLength, 0, 0), false));
+    yAxis->setEnd(canvasProjection->computeCanvasPoint(Coord(0, axisLength, 0), false));
+    zAxis->setEnd(canvasProjection->computeCanvasPoint(Coord(0, 0, axisLength), false));
+    xLabel->setPosition(canvasProjection->computeCanvasPoint(Coord(axisLength, 0, 0), false));
+    yLabel->setPosition(canvasProjection->computeCanvasPoint(Coord(0, axisLength, 0), false));
+    zLabel->setPosition(canvasProjection->computeCanvasPoint(Coord(0, 0, axisLength), false));
 }
 
 void SceneCanvasVisualizer::handleParameterChange(const char *name)