Imported existing code

indra/newview/llviewerlayer.cpp

@@ -0,0 +1,106 @@
+/** 
+ * @file llviewerlayer.cpp
+ * @brief LLViewerLayer class implementation
+ *
+ * $LicenseInfo:firstyear=2002&license=viewergpl$
+ * 
+ * Copyright (c) 2002-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#include "llviewerprecompiledheaders.h"
+
+#include "llviewerlayer.h"
+#include "llerror.h"
+#include "llmath.h"
+
+LLViewerLayer::LLViewerLayer(const S32 width, const F32 scale)
+{
+	mWidth = width;
+	mScale = scale;
+	mScaleInv = 1.f/scale;
+	mDatap = new F32[width*width];
+
+	for (S32 i = 0; i < width*width; i++)
+	{
+		*(mDatap + i) = 0.f;
+	}
+}
+
+LLViewerLayer::~LLViewerLayer()
+{
+	delete[] mDatap;
+	mDatap = NULL;
+}
+
+F32 LLViewerLayer::getValue(const S32 x, const S32 y) const
+{
+//	llassert(x >= 0);
+//	llassert(x < mWidth);
+//	llassert(y >= 0);
+//	llassert(y < mWidth);
+
+	return *(mDatap + x + y*mWidth);
+}
+
+F32 LLViewerLayer::getValueScaled(const F32 x, const F32 y) const
+{
+	S32 x1, x2, y1, y2;
+	F32 x_frac, y_frac;
+
+	x_frac = x*mScaleInv;
+	x1 = llfloor(x_frac);
+	x2 = x1 + 1;
+	x_frac -= x1;
+
+	y_frac = y*mScaleInv;
+	y1 = llfloor(y_frac);
+	y2 = y1 + 1;
+	y_frac -= y1;
+
+	x1 = llmin((S32)mWidth-1, x1);
+	x1 = llmax(0, x1);
+	x2 = llmin((S32)mWidth-1, x2);
+	x2 = llmax(0, x2);
+	y1 = llmin((S32)mWidth-1, y1);
+	y1 = llmax(0, y1);
+	y2 = llmin((S32)mWidth-1, y2);
+	y2 = llmax(0, y2);
+
+	// Take weighted average of all four points (bilinear interpolation)
+	S32 row1 = y1 * mWidth;
+	S32 row2 = y2 * mWidth;
+	
+	// Access in squential order in memory, and don't use immediately.
+	F32 row1_left  = mDatap[ row1 + x1 ];
+	F32 row1_right = mDatap[ row1 + x2 ];
+	F32 row2_left  = mDatap[ row2 + x1 ];
+	F32 row2_right = mDatap[ row2 + x2 ];
+	
+	F32 row1_interp = row1_left - x_frac * (row1_left - row1_right);
+	F32 row2_interp = row2_left - x_frac * (row2_left - row2_right);
+	
+	return row1_interp - y_frac * (row1_interp - row2_interp);
+}