/indra/newview/llviewerlayer.cpp
C++ | 100 lines | 54 code | 15 blank | 31 comment | 1 complexity | cb2293c4092b7eb896b46c1ab7c268aa MD5 | raw file
Possible License(s): LGPL-2.1
- /**
- * @file llviewerlayer.cpp
- * @brief LLViewerLayer class implementation
- *
- * $LicenseInfo:firstyear=2002&license=viewerlgpl$
- * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License only.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
- * $/LicenseInfo$
- */
- #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);
- }