BGE: Fix T43822 Videotexture does not use sky color for off-screen

rendering

Make scene background color as default for render-to-texture instead of
current blue color (0, 0, 255).

It is very useful for mirrors setups.

Reviewers: moguri, ben2610, sybren, panzergame, hg1

Reviewed By: panzergame, hg1, moguri

Subscribers: mpan3

Differential Revision: https://developer.blender.org/D1287

source/gameengine/Ketsji/KX_WorldInfo.cpp

@@ -100,6 +100,11 @@ void KX_WorldInfo::setBackColor(float r, float g, float b)
 	}
 }
 
+const float *KX_WorldInfo::getBackColor(void) const
+{
+	return m_backgroundcolor;
+}
+
 void KX_WorldInfo::setMistType(short type)
 {
 	m_misttype = type;

source/gameengine/Ketsji/KX_WorldInfo.h

@@ -88,6 +88,7 @@ public:
 	void setMistIntensity(float intensity);
 	void setMistColor(float r, float g, float b);
 	void setBackColor(float r, float g, float b);
+	const float *getBackColor() const;
 	void setAmbientColor(float r, float g, float b);
 	void UpdateBackGround();
 	void UpdateWorldSettings();

source/gameengine/VideoTexture/ImageRender.cpp

@@ -75,8 +75,8 @@ ImageRender::ImageRender (KX_Scene *scene, KX_Camera * camera) :
     m_mirrorHalfWidth(0.f),
     m_mirrorHalfHeight(0.f)
 {
-	// initialize background color
+	// initialize background color to scene background color as default
-	setBackground(0, 0, 255, 255);
+	setBackgroundFromScene(m_scene);
 	// retrieve rendering objects
 	m_engine = KX_GetActiveEngine();
 	m_rasterizer = m_engine->GetRasterizer();
@@ -100,6 +100,18 @@ void ImageRender::setBackground (int red, int green, int blue, int alpha)
 	m_background[3] = (alpha < 0) ? 0.f : (alpha > 255) ? 1.f : float(alpha)/255.f;
 }
 
+// set background color from scene
+void ImageRender::setBackgroundFromScene (KX_Scene *scene)
+{
+	if (scene) {
+		const float *background_color = scene->GetWorldInfo()->getBackColor();
+		setBackground((int) (background_color[0] * 255.0f), (int) (background_color[1] * 255.0f), (int) (background_color[2] * 255.0f), 255);
+	}
+	else {
+		setBackground(0, 0, 255, 255);
+	}
+}
+
 
 // capture image from viewport
 void ImageRender::calcImage (unsigned int texId, double ts)
@@ -733,7 +745,8 @@ ImageRender::ImageRender (KX_Scene *scene, KX_GameObject *observer, KX_GameObjec
 	m_mirrorX = m_mirrorY.cross(m_mirrorZ);
 	m_render = true;
 
-	setBackground(0, 0, 255, 255);
+	// set mirror background color to scene background color as default
+	setBackgroundFromScene(m_scene);
 }
 
 

source/gameengine/VideoTexture/ImageRender.h

@@ -100,7 +100,7 @@ protected:
 	void Render();
 	void SetupRenderFrame(KX_Scene *scene, KX_Camera* cam);
 	void RenderFrame(KX_Scene* scene, KX_Camera* cam);
-	void SetBackGround(KX_WorldInfo* wi);
+	void setBackgroundFromScene(KX_Scene *scene);
 	void SetWorldSettings(KX_WorldInfo* wi);
 };