Fixing camera clip space transforms to properly flip the Y axis

BansheeEditor/Source/BsGizmoManager.cpp

@@ -557,11 +557,11 @@ namespace BansheeEngine
 			UINT32 vertOffset = i * 4;
 
 			indices[0] = vertOffset + 0;
-			indices[1] = vertOffset + 3;
-			indices[2] = vertOffset + 1;
-			indices[3] = vertOffset + 1;
-			indices[4] = vertOffset + 3;
-			indices[5] = vertOffset + 2;
+			indices[1] = vertOffset + 1;
+			indices[2] = vertOffset + 2;
+			indices[3] = vertOffset + 0;
+			indices[4] = vertOffset + 2;
+			indices[5] = vertOffset + 3;
 
 			indices += 6;
 		}
@@ -784,7 +784,11 @@ namespace BansheeEngine
 		float near = rs.getMinimumDepthInputValue();
 		float far = rs.getMaximumDepthInputValue();
 
-		projMat.makeProjectionOrtho(left, right, top, bottom, -near, -far); // Minus near/far because Z is flipped for normalized device coords
+		// Top/bottom have been swapped because we're moving from window coordinates (origin top left)
+		// to normalized device coordinates (origin bottom left)
+		// Negative near/far because Z is flipped for normalized device coordinates 
+		// (positive Z goes into screen as opposed to view space here we're looking along negative Z)
+		projMat.makeProjectionOrtho(left, right, top, bottom, -near, -far);
 
 		if (!usePickingMaterial)
 		{

BansheeEditor/Source/BsSceneEditorWidget.cpp

@@ -153,7 +153,6 @@ namespace BansheeEngine
 		if (!HandleManager::instance().isHandleActive())
 		{
 			// TODO - Handle multi-selection (i.e. selection rectangle when dragging)
-			// TODO - Handle selecting gizmos (will likely require slight refactor of ScenePicking)
 			HSceneObject pickedObject = ScenePicking::instance().pickClosestObject(mCamera, scenePos, Vector2I(1, 1));
 
 			if (pickedObject)

BansheeEngine/Source/BsCameraHandler.cpp

@@ -531,7 +531,7 @@ namespace BansheeEngine
 	{
 		Vector2 clipPoint;
 		clipPoint.x = (float)(((screenPoint.x - mViewport->getX()) / (float)mViewport->getWidth()) * 2.0f - 1.0f);
-		clipPoint.y = (float)(((screenPoint.y - mViewport->getY()) / (float)mViewport->getHeight()) * 2.0f - 1.0f);
+		clipPoint.y = (float)((1.0f - ((screenPoint.y - mViewport->getY()) / (float)mViewport->getHeight())) * 2.0f - 1.0f);
 
 		return clipPoint;
 	}
@@ -568,8 +568,8 @@ namespace BansheeEngine
 	Vector2I CameraHandler::clipToScreenPoint(const Vector2& clipPoint) const
 	{
 		Vector2I screenPoint;
-		screenPoint.x = Math::roundToInt(mViewport->getX() + (clipPoint.x + 1.0f) * mViewport->getWidth() * 0.5f);
-		screenPoint.y = Math::roundToInt(mViewport->getY() + (clipPoint.y + 1.0f) * mViewport->getHeight() * 0.5f);
+		screenPoint.x = Math::roundToInt(mViewport->getX() + ((clipPoint.x + 1.0f) * 0.5f) * mViewport->getWidth());
+		screenPoint.y = Math::roundToInt(mViewport->getY() + (1.0f - (clipPoint.y + 1.0f) * 0.5f) * mViewport->getHeight());
 
 		return screenPoint;
 	}

BansheeUtility/Source/BsMatrix4.cpp

@@ -246,11 +246,16 @@ namespace BansheeEngine
 		}
 	}
 
-	void Matrix4::makeProjectionOrtho(float left, float right, float bottom,
-		float top, float near, float far)
+	void Matrix4::makeProjectionOrtho(float left, float right, float top,
+		float bottom, float near, float far)
 	{
+		// Create a matrix that transforms coordinate to normalized device coordinate in range:
+		// Left -1 - Right 1
+		// Bottom -1 - Top 1
+		// Near -1 - Far 1
+
 		float deltaX = right - left;
-		float deltaY = top - bottom;
+		float deltaY = bottom - top;
 		float deltaZ = far - near;
 
 		m[0][0] = 2.0F / deltaX;
@@ -259,9 +264,9 @@ namespace BansheeEngine
 		m[0][3] = -(right + left) / deltaX;
 
 		m[1][0] = 0.0f;
-		m[1][1] = 2.0F / deltaY;
+		m[1][1] = -2.0F / deltaY;
 		m[1][2] = 0.0f;
-		m[1][3] = -(top + bottom) / deltaY;
+		m[1][3] = (top + bottom) / deltaY;
 
 		m[2][0] = 0.0f;
 		m[2][1] = 0.0f;

MBansheeEditor/DbgGizmo.cs

@@ -28,7 +28,6 @@ namespace BansheeEditor
                 target.sceneObject.position + 8.5f * Vector3.xAxis);
             Gizmos.DrawFrustum(target.sceneObject.position + 10 * Vector3.xAxis, 1920.0f / 1080.0f, 90, 1.0f, 1000.0f);
 
-            Gizmos.color = Color.red;
             Gizmos.DrawIcon(target.sceneObject.position + new Vector3(0, 10, 0), iconTexture, false);
         }
     }

SceneView.txt

@@ -3,7 +3,6 @@
   - Make a C# wrapper for Camera and Renderable
 
 REFACTOR material getParams* and related classes. Those params should update all gpu program params that share that variable, not just the first found
-Add a way to render GUI image without alpha
 Line slider collider intersection doesn't work properly
 Handles need to render in front of everything
 Clicking on empty space needs to deselect everything