UPBGE: Use only min and max operation for computing AABB.

Previously the code parts computing AABB were using a condition to detect the first point computed used to initialize the AABB dimensions. But this method requiered a test at each points and also to be able to detect the first point. To avoid these restrictions the AABB dimension is initialized to float min for max and float max for min. This make sure that any point will affect the AABB the first time.
UPBGE · Oct 16, 2017 · b339165 · b339165
1 parent 9a77819
commit b339165
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Showing 4 changed files with 28 additions and 51 deletions.
diff --git a/source/gameengine/Converter/BL_SkinDeformer.cpp b/source/gameengine/Converter/BL_SkinDeformer.cpp
@@ -276,10 +276,9 @@ void BL_SkinDeformer::UpdateTransverts()
 		return;
 	}
 
-	bool first = true;
 	// AABB Box : min/max.
-	MT_Vector3 aabbMin;
-	MT_Vector3 aabbMax;
+	MT_Vector3 aabbMin(FLT_MAX, FLT_MAX, FLT_MAX);
+	MT_Vector3 aabbMax(FLT_MIN, FLT_MIN, FLT_MIN);
 
 	// the vertex cache is unique to this deformer, no need to update it
 	// if it wasn't updated! We must update all the materials at once
@@ -300,19 +299,12 @@ void BL_SkinDeformer::UpdateTransverts()
 				continue;
 			}
 
-			// For the first vertex of the mesh, only initialize AABB.
-			if (first) {
-				aabbMin = aabbMax = vertpos;
-				first = false;
-			}
-			else {
-				aabbMin.x() = std::min(aabbMin.x(), vertpos.x());
-				aabbMin.y() = std::min(aabbMin.y(), vertpos.y());
-				aabbMin.z() = std::min(aabbMin.z(), vertpos.z());
-				aabbMax.x() = std::max(aabbMax.x(), vertpos.x());
-				aabbMax.y() = std::max(aabbMax.y(), vertpos.y());
-				aabbMax.z() = std::max(aabbMax.z(), vertpos.z());
-			}
+			aabbMin.x() = std::min(aabbMin.x(), vertpos.x());
+			aabbMin.y() = std::min(aabbMin.y(), vertpos.y());
+			aabbMin.z() = std::min(aabbMin.z(), vertpos.z());
+			aabbMax.x() = std::max(aabbMax.x(), vertpos.x());
+			aabbMax.y() = std::max(aabbMax.y(), vertpos.y());
+			aabbMax.z() = std::max(aabbMax.z(), vertpos.z());
 		}
 
 		array->SetModifiedFlag(RAS_IDisplayArray::POSITION_MODIFIED | RAS_IDisplayArray::NORMAL_MODIFIED);

diff --git a/source/gameengine/Ketsji/KX_FontObject.cpp b/source/gameengine/Ketsji/KX_FontObject.cpp
@@ -224,22 +224,16 @@ void KX_FontObject::GetTextAabb(MT_Vector2& min, MT_Vector2& max)
 
 	BLF_size(m_fontid, size, m_dpi);
 
+	min = MT_Vector2(FLT_MAX, FLT_MAX);
+	max = MT_Vector2(FLT_MIN, FLT_MIN);
 	for (unsigned short i = 0, size = m_texts.size(); i < size; ++i) {
 		rctf box;
 		const std::string& text = m_texts[i];
 		BLF_boundbox(m_fontid, text.c_str(), text.size(), &box);
-		if (i == 0) {
-			min.x() = box.xmin;
-			min.y() = box.ymin;
-			max.x() = box.xmax;
-			max.y() = box.ymax;
-		}
-		else {
-			min.x() = std::min(min.x(), box.xmin);
-			min.y() = std::min(min.y(), box.ymin - lineSpacing * i);
-			max.x() = std::max(max.x(), box.xmax);
-			max.y() = std::max(max.y(), box.ymax - lineSpacing * i);
-		}
+		min.x() = std::min(min.x(), box.xmin);
+		min.y() = std::min(min.y(), box.ymin - lineSpacing * i);
+		max.x() = std::max(max.x(), box.xmax);
+		max.y() = std::max(max.y(), box.ymax - lineSpacing * i);
 	}
 
 	min *= aspect;

diff --git a/source/gameengine/Ketsji/KX_SoftBodyDeformer.cpp b/source/gameengine/Ketsji/KX_SoftBodyDeformer.cpp
@@ -103,8 +103,8 @@ void KX_SoftBodyDeformer::Apply(RAS_MeshMaterial *meshmat, RAS_IDisplayArray *ar
 	}
 
 	// AABB Box : min/max.
-	MT_Vector3 aabbMin;
-	MT_Vector3 aabbMax;
+	MT_Vector3 aabbMin(FLT_MAX, FLT_MAX, FLT_MAX);
+	MT_Vector3 aabbMax(FLT_MIN, FLT_MIN, FLT_MIN);
 
 	for (unsigned int i = 0, size = array->GetVertexCount(); i < size; ++i) {
 		RAS_IVertex *v = array->GetVertex(i);
@@ -129,17 +129,12 @@ void KX_SoftBodyDeformer::Apply(RAS_MeshMaterial *meshmat, RAS_IDisplayArray *ar
 		// Extract object transform from the vertex position.
 		const MT_Vector3 ptWorld = (pt - pos) * rot * invertscale;
 		// if the AABB need an update.
-		if (i == 0) {
-			aabbMin = aabbMax = ptWorld;
-		}
-		else {
-			aabbMin.x() = std::min(aabbMin.x(), ptWorld.x());
-			aabbMin.y() = std::min(aabbMin.y(), ptWorld.y());
-			aabbMin.z() = std::min(aabbMin.z(), ptWorld.z());
-			aabbMax.x() = std::max(aabbMax.x(), ptWorld.x());
-			aabbMax.y() = std::max(aabbMax.y(), ptWorld.y());
-			aabbMax.z() = std::max(aabbMax.z(), ptWorld.z());
-		}
+		aabbMin.x() = std::min(aabbMin.x(), ptWorld.x());
+		aabbMin.y() = std::min(aabbMin.y(), ptWorld.y());
+		aabbMin.z() = std::min(aabbMin.z(), ptWorld.z());
+		aabbMax.x() = std::max(aabbMax.x(), ptWorld.x());
+		aabbMax.y() = std::max(aabbMax.y(), ptWorld.y());
+		aabbMax.z() = std::max(aabbMax.z(), ptWorld.z());
 	}
 
 	array->UpdateFrom(origarray, origarray->GetModifiedFlag() &

diff --git a/source/gameengine/Rasterizer/RAS_BoundingBox.cpp b/source/gameengine/Rasterizer/RAS_BoundingBox.cpp
@@ -161,19 +161,15 @@ void RAS_MeshBoundingBox::Update(bool force)
 		return;
 	}
 
-	for (unsigned short i = 0, size = m_displayArrayList.size(); i < size; ++i) {
-		RAS_IDisplayArray *displayArray = m_displayArrayList[i];
+	m_aabbMin = MT_Vector3(FLT_MAX, FLT_MAX, FLT_MAX);
+	m_aabbMax = MT_Vector3(FLT_MIN, FLT_MIN, FLT_MIN);
+
+	for (RAS_IDisplayArray *displayArray : m_displayArrayList) {
 		// For each vertex.
-		for (unsigned int j = 0, size = displayArray->GetVertexCount(); j < size; ++j) {
-			RAS_IVertex *vert = displayArray->GetVertex(j);
+		for (unsigned int i = 0, size = displayArray->GetVertexCount(); i < size; ++i) {
+			RAS_IVertex *vert = displayArray->GetVertex(i);
 			const MT_Vector3 vertPos = vert->xyz();
 
-			// Initialize the AABB to the first vertex position.
-			if (j == 0 && i == 0) {
-				m_aabbMin = m_aabbMax = vertPos;
-				continue;
-			}
-
 			m_aabbMin.x() = std::min(m_aabbMin.x(), vertPos.x());
 			m_aabbMin.y() = std::min(m_aabbMin.y(), vertPos.y());
 			m_aabbMin.z() = std::min(m_aabbMin.z(), vertPos.z());