[Sofa.GL] DrawToolGL: Auto-scale indices display based on camera distance

Sofa/Component/SolidMechanics/Spring/src/sofa/component/solidmechanics/spring/PolynomialRestShapeSpringsForceField.inl

@@ -40,7 +40,7 @@ PolynomialRestShapeSpringsForceField<DataTypes>::PolynomialRestShapeSpringsForce
     , d_recomputeIndices(initData(&d_recomputeIndices, false, "recompute_indices", "Recompute indices (should be false for BBOX)"))
     , d_drawSpring(initData(&d_drawSpring,false,"drawSpring","draw Spring"))
     , d_springColor(initData(&d_springColor, sofa::type::RGBAColor(0.0f, 1.0f, 0.0f, 1.0f), "springColor","spring color"))
-    , d_showIndicesScale(initData(&d_showIndicesScale, (float)0.02, "showIndicesScale", "Scale for indices display. (default=0.02)"))
+    , d_showIndicesScale(initData(&d_showIndicesScale, (float)1.0, "showIndicesScale", "Multiplier for indices display size. Indices are auto-scaled to maintain a constant screen size."))
     , d_zeroLength(initData(&d_zeroLength,"initialLength","initial virtual length of the spring"))
     , d_smoothShift(initData(&d_smoothShift,static_cast<Real>(0.0),"smoothShift","denominator correction adding shift value"))
     , d_smoothScale(initData(&d_smoothScale,static_cast<Real>(1.0),"smoothScale","denominator correction adding scale"))
@@ -432,7 +432,7 @@ void PolynomialRestShapeSpringsForceField<DataTypes>::draw(const core::visual::V
 
 
     // draw connected point indices
-    Real scale = (vparams->sceneBBox().maxBBox() - vparams->sceneBBox().minBBox()).norm() * d_showIndicesScale.getValue();
+    Real scale = d_showIndicesScale.getValue();
 
     type::vector<type::Vec3> positions;
     for (sofa::Index i = 0; i < indices.size(); i++) {

Sofa/Component/StateContainer/src/sofa/component/statecontainer/MechanicalObject.inl

@@ -151,7 +151,7 @@ MechanicalObject<DataTypes>::MechanicalObject()
     , showObject(initData(&showObject, (bool) false, "showObject", "Show objects. (default=false)"))
     , showObjectScale(initData(&showObjectScale, 0.1f, "showObjectScale", "Scale for object display. (default=0.1)"))
     , showIndices(initData(&showIndices, (bool) false, "showIndices", "Show indices. (default=false)"))
-    , showIndicesScale(initData(&showIndicesScale, 0.02f, "showIndicesScale", "Scale for indices display. (default=0.02)"))
+    , showIndicesScale(initData(&showIndicesScale, 1.0f, "showIndicesScale", "Scaling factor for indices display size. Indices are auto-scaled to maintain a constant screen size."))
     , showVectors(initData(&showVectors, (bool) false, "showVectors", "Show velocity. (default=false)"))
     , showVectorsScale(initData(&showVectorsScale, 0.0001f, "showVectorsScale", "Scale for vectors display. (default=0.0001)"))
     , drawMode(initData(&drawMode,0,"drawMode","The way vectors will be drawn:\n- 0: Line\n- 1:Cylinder\n- 2: Arrow.\n\nThe DOFS will be drawn:\n- 0: point\n- >1: sphere. (default=0)"))
@@ -2630,14 +2630,12 @@ SReal MechanicalObject<DataTypes>::getConstraintJacobianTimesVecDeriv(unsigned i
 template <class DataTypes>
 inline void MechanicalObject<DataTypes>::drawIndices(const core::visual::VisualParams* vparams)
 {
-    const float scale = (float)((vparams->sceneBBox().maxBBox() - vparams->sceneBBox().minBBox()).norm() * showIndicesScale.getValue());
-
     std::vector<type::Vec3> positions;
     positions.reserve(d_size.getValue());
     for (int i = 0; i <d_size.getValue(); ++i)
         positions.push_back(type::Vec3(getPX(i), getPY(i), getPZ(i)));
 
-    vparams->drawTool()->draw3DText_Indices(positions, scale, d_color.getValue());
+    vparams->drawTool()->draw3DText_Indices(positions, showIndicesScale.getValue(), d_color.getValue());
 }
 
 template <class DataTypes>

Sofa/Component/Topology/Container/Dynamic/src/sofa/component/topology/container/dynamic/PointSetGeometryAlgorithms.inl

@@ -34,7 +34,7 @@ using sofa::core::objectmodel::ComponentState;
 template <class DataTypes>
  PointSetGeometryAlgorithms< DataTypes >::PointSetGeometryAlgorithms()        
     : GeometryAlgorithms()
-    , d_showIndicesScale (core::objectmodel::Base::initData(&d_showIndicesScale, (float) 0.02, "showIndicesScale", "Debug : scale for view topology indices"))
+    , d_showIndicesScale (core::objectmodel::Base::initData(&d_showIndicesScale, (float) 1.0, "showIndicesScale", "Debug : multiplier for view topology indices size. Indices are auto-scaled to maintain a constant screen size."))
     , d_showPointIndices (core::objectmodel::Base::initData(&d_showPointIndices, (bool) false, "showPointIndices", "Debug : view Point indices"))
     , d_tagMechanics( initData(&d_tagMechanics,std::string(),"tagMechanics","Tag of the Mechanical Object"))
     , l_topology(initLink("topology", "link to the topology container"))
@@ -85,12 +85,7 @@ void PointSetGeometryAlgorithms< DataTypes >::reinit()
 template <class DataTypes>
 float PointSetGeometryAlgorithms< DataTypes >::getIndicesScale() const
 {
-    const sofa::type::BoundingBox& bbox = this->getContext()->f_bbox.getValue();
-    const float bbDiff = float((bbox.maxBBox() - bbox.minBBox()).norm());
-    if (std::isinf(bbDiff))
-        return d_showIndicesScale.getValue();
-    else
-        return bbDiff * d_showIndicesScale.getValue();
+    return d_showIndicesScale.getValue();
 }
 
 

Sofa/Component/Visual/src/sofa/component/visual/VisualPointCloud.inl

@@ -158,10 +158,7 @@ void VisualPointCloud<DataTypes>::doDrawVisual(const core::visual::VisualParams*
 template <class DataTypes>
 void VisualPointCloud<DataTypes>::drawIndices(const core::visual::VisualParams* vparams) const
 {
-    const float scale = static_cast<float>(
-        (vparams->sceneBBox().maxBBox() - vparams->sceneBBox().minBBox()).norm() *
-        d_indicesScale.getValue());
-    vparams->drawTool()->draw3DText_Indices(convertCoord(), scale, d_indicesColor.getValue());
+    vparams->drawTool()->draw3DText_Indices(convertCoord(), d_indicesScale.getValue(), d_indicesColor.getValue());
 }
 
 template <class DataTypes>

Sofa/GL/src/sofa/gl/glText.cpp

@@ -184,13 +184,32 @@ void GlText::textureDraw_Indices(const type::vector<type::Vec3>& positions, cons
     static const float worldHeight = 1.0;
     static const float worldWidth = 0.5;
 
+    // Auto-scaling: retrieve projection matrix and viewport to maintain
+    // a constant screen-space text size regardless of camera distance
+    GLfloat projMatrix[16];
+    GLint viewport[4];
+    glGetFloatv(GL_PROJECTION_MATRIX, projMatrix);
+    glGetIntegerv(GL_VIEWPORT, viewport);
+
+    const float viewportHeight = static_cast<float>(viewport[3]);
+    // Column-major P[1][1] = cot(fov_y/2) for perspective
+    const float p11 = projMatrix[5];
+    // Column-major P[3][3]: 0 for perspective, ~1 for orthographic
+    const bool isPerspective = (projMatrix[15] < 0.5f);
+    // Base text height in pixels (before user multiplier)
+    static const float baseFontPixelHeight = 30.0f;
+
+    if (p11 == 0.0f || viewportHeight == 0.0f)
+        return;
+
     glPushAttrib(GL_TEXTURE_BIT);
     glEnable(GL_TEXTURE_2D);
 
     glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); // multiply tex color with glColor
-    //glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); // only tex color (no glColor)
     glEnable(GL_ALPHA_TEST);
     glAlphaFunc(GL_GREATER, 0.0);
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
     s_asciiTexture->bind();
 
@@ -216,10 +235,23 @@ void GlText::textureDraw_Indices(const type::vector<type::Vec3>& positions, cons
         type::Vec3f temp(positions[i][0], positions[i][1], positions[i][2]);
         temp = modelviewM.transform(temp);
 
+        // Compute auto-scale: one pixel in world units = 2*depth / (p11 * viewportHeight)
+        float autoScale;
+        if (isPerspective)
+        {
+            float depth = -temp[2];
+            if (depth < 1e-5f) depth = 1e-5f;
+            autoScale = baseFontPixelHeight * scale * 2.0f * depth / (p11 * viewportHeight);
+        }
+        else
+        {
+            autoScale = baseFontPixelHeight * scale * 2.0f / (p11 * viewportHeight);
+        }
+
         glLoadIdentity();
         //translate a little bit to center the text on the position (instead of starting from a top-left position)
-        glTranslatef(temp[0] - (worldWidth*length*scale)*0.5f, temp[1] + worldHeight*scale*0.5f, temp[2]);
-        glScalef(scale, scale, scale);
+        glTranslatef(temp[0] - (worldWidth*length*autoScale)*0.5f, temp[1] + worldHeight*autoScale*0.5f, temp[2]);
+        glScalef(autoScale, autoScale, autoScale);
         glRotatef(180.0, 1, 0, 0);
         for (std::size_t j = 0; j < length; j++)
         {
@@ -262,6 +294,7 @@ void GlText::textureDraw_Indices(const type::vector<type::Vec3>& positions, cons
 
     s_asciiTexture->unbind();
     glDisable(GL_ALPHA_TEST);
+    glDisable(GL_BLEND);
     glPopAttrib();
 
 

Sofa/GUI/Common/src/sofa/gui/common/BaseViewer.cpp

@@ -472,8 +472,7 @@ void BaseViewer::drawSelection(sofa::core::visual::VisualParams* vparams)
 
             if(m_showSelectedObjectIndices && !positions.empty() && validBox)
             {
-                const float scale = (box.maxBBox() - box.minBBox()).norm() * m_visualScaling;
-                drawTool->draw3DText_Indices(positions, scale, m_selectionColor);
+                drawTool->draw3DText_Indices(positions, m_visualScaling, m_selectionColor);
             }
 
             continue;

Sofa/GUI/Common/src/sofa/gui/common/BaseViewer.h

@@ -133,7 +133,7 @@ class SOFA_GUI_COMMON_API BaseViewer
     bool m_showSelectedObjectVolumes {false};
     bool m_showSelectedObjectIndices {false};
     type::RGBAColor m_selectionColor {type::RGBAColor::purple()};
-    float m_visualScaling {0.2};
+    float m_visualScaling {1.0};
 
 protected:
     void drawIndices(const sofa::type::BoundingBox& bbox, const std::vector<sofa::type::Vec3>& positions);