phoenix-firestorm/indra/newview/llpatchvertexarray.h

52 lines
1.7 KiB
C++

/**
* @file llpatchvertexarray.h
* @brief description of Surface class
*
* Copyright (c) 2001-$CurrentYear$, Linden Research, Inc.
* $License$
*/
#ifndef LL_LLPATCHVERTEXARRAY_H
#define LL_LLPATCHVERTEXARRAY_H
// A LLPatchVertexArray is really just a structure of vertex arrays for
// rendering a "patch" of a certain size.
//
// A "patch" is currently a sub-square of a larger square array of data
// we call a "surface".
class LLPatchVertexArray
{
public:
LLPatchVertexArray();
LLPatchVertexArray(U32 surface_width, U32 patch_width, F32 meters_per_grid);
virtual ~LLPatchVertexArray();
void create(U32 surface_width, U32 patch_width, F32 meters_per_grid);
void destroy();
void init();
public:
U32 mSurfaceWidth; // grid points on one side of a LLSurface
U32 mPatchWidth; // grid points on one side of a LLPatch
U32 mPatchOrder; // 2^mPatchOrder >= mPatchWidth
U32 *mRenderLevelp; // Look-up table : render_stride -> render_level
U32 *mRenderStridep; // Look-up table : render_level -> render_stride
// We want to be able to render a patch from multiple resolutions.
// The lowest resolution has two triangles, and the highest has
// 2*mPatchWidth*mPatchWidth triangles.
//
// mPatchWidth is not hard-coded, so we don't know how much memory
// to allocate to the vertex arrays until it is set. Once it is
// set, we will calculate how much total memory to allocate for the
// vertex arrays, and then keep track of their lengths and locations
// in the memory bank.
//
// A Patch has three regions that need vertex arrays: middle, north,
// and east. For each region there are three items that must be
// kept track of: data, offset, and length.
};
#endif