ovis: implement setting diffuse color

Author: paroj

modules/ovis/include/opencv2/ovis.hpp

@@ -36,6 +36,7 @@ enum MaterialProperty
     MATERIAL_LINE_WIDTH,
     MATERIAL_OPACITY,
     MATERIAL_EMISSIVE,
+    MATERIAL_DIFFUSE,
     MATERIAL_TEXTURE0,
     MATERIAL_TEXTURE = MATERIAL_TEXTURE0,
     MATERIAL_TEXTURE1,

modules/ovis/src/ovis.cpp

@@ -171,6 +171,14 @@ static SceneNode& _getSceneNode(SceneManager* sceneMgr, const String& name)
     return *mo->getParentSceneNode();
 }
 
+static ColourValue convertColor(const Scalar& val)
+{
+    // BGR 0..255 (uchar) to RGB 0..1
+    ColourValue ret = ColourValue(val[2], val[1], val[0]) / 255;
+    ret.saturate();
+    return ret;
+}
+
 struct Application : public OgreBites::ApplicationContext, public OgreBites::InputListener
 {
     Ptr<LogManager> logMgr;
@@ -508,10 +516,7 @@ class WindowSceneImpl : public WindowScene
     {
         // hide background plane
         bgplane->setVisible(false);
-
-        // BGRA as uchar
-        ColourValue _color = ColourValue(color[2], color[1], color[0], color[3]) / 255;
-        rWin->getViewport(0)->setBackgroundColour(_color);
+        rWin->getViewport(0)->setBackgroundColour(convertColor(color));
     }
 
     void createEntity(const String& name, const String& meshname, InputArray tvec, InputArray rot) CV_OVERRIDE
@@ -970,8 +975,8 @@ void setMaterialProperty(const String& name, int prop, const Scalar& val)
     CV_Assert(mat);
 
     Pass* rpass = mat->getTechniques()[0]->getPasses()[0];
-    ColourValue col;
 
+    ColourValue col;
     switch (prop)
     {
     case MATERIAL_POINT_SIZE:
@@ -984,10 +989,13 @@ void setMaterialProperty(const String& name, int prop, const Scalar& val)
         rpass->setSceneBlending(SBT_TRANSPARENT_ALPHA);
         rpass->setDepthWriteEnabled(false);
         break;
+    case MATERIAL_DIFFUSE:
+        col = convertColor(val);
+        col.a = rpass->getDiffuse().a;
+        rpass->setDiffuse(col);
+        break;
     case MATERIAL_EMISSIVE:
-        col = ColourValue(val[2], val[1], val[0]) / 255; // BGR as uchar
-        col.saturate();
-        rpass->setEmissive(col);
+        rpass->setEmissive(convertColor(val));
         break;
     case MATERIAL_LINE_WIDTH:
         rpass->setLineWidth(val[0]);