graphicsdeviceinterface/screendriver/inc/CoordTransformation.inl
author Matt Plumtree <matt.plumtree@nokia.com>
Fri, 23 Apr 2010 17:57:02 +0100
branchNewGraphicsArchitecture
changeset 39 a4b63488e0b0
parent 0 5d03bc08d59c
permissions -rw-r--r--
Revise some of the compositor performance improvements to improve correctness. Implement pixel blending using a variation of Jim Blinn's no-division blending algorithm. Move transparency type simplification further up the composition code. Remove some unnecessary fields. Output to YUV implementation needs revision as it is actually converting from YUV (copy of source conversion code).

// Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).
// All rights reserved.
// This component and the accompanying materials are made available
// under the terms of "Eclipse Public License v1.0"
// which accompanies this distribution, and is available
// at the URL "http://www.eclipse.org/legal/epl-v10.html".
//
// Initial Contributors:
// Nokia Corporation - initial contribution.
//
// Contributors:
//
// Description:
// Converts logical coordinate value to physical coordinate value.
// Then adjusts the value, assuming that it must be within the drawing rectangle.
// The first, "<0" check is arguable - should it be there or not!?
// Because it HIDES negative values of "x" coordinate, so possible programmer's errors!
// But with used logical to physical transformation it is possible that some logical
// coordinate value might be transformed to negative physical coordinate value and 
// then it has to be checked and set to 0.
// 
//

inline TInt Log2Phys(TInt aCoordVal, TInt aScalingOrigin, TInt aScalingFactor, TInt aSize) 
	{
	aCoordVal = aScalingOrigin + aCoordVal * aScalingFactor;
	return aCoordVal < 0 ? 0 : aCoordVal >= aSize ? (aSize - 1) : aCoordVal;
	}

//Converts logical coordinate value to physical coordinate value.
//Then adjusts the value, assuming that it represents right-bottom coordinate of the logical 
//rectangle. The first, "<0" check is arguable - should it be there or not!?
//Because it HIDES negative values of "x" coordinate, so possible programmer's errors!
//But with used logical to physical transformation it is possible that some logical
//coordinate value is transformed to negative physical coordinate value and then it has to
//be checked and set to 0.
inline TInt RBtmLog2Phys(TInt aCoordVal, TInt aScalingOrigin, TInt aScalingFactor, TInt aSize) 
	{
	aCoordVal = aScalingOrigin + aCoordVal * aScalingFactor;
	return aCoordVal < 0 ? 0 : aCoordVal > aSize ? aSize : aCoordVal;
	}