ref: bea7b7bf8ccbc2bc41906517079e76fcfb31cb5a
dir: /code/renderer/tr_curve.c/
/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
This file is part of Quake III Arena source code.
Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.
Quake III Arena source code 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
===========================================================================
*/
#include "tr_local.h"
/*
This file does all of the processing necessary to turn a raw grid of points
read from the map file into a srfGridMesh_t ready for rendering.
The level of detail solution is direction independent, based only on subdivided
distance from the true curve.
Only a single entry point:
srfGridMesh_t *R_SubdividePatchToGrid( int width, int height,
drawVert_t points[MAX_PATCH_SIZE*MAX_PATCH_SIZE] ) {
*/
/*
============
LerpDrawVert
============
*/
static void LerpDrawVert( drawVert_t *a, drawVert_t *b, drawVert_t *out ) {
out->xyz[0] = 0.5f * (a->xyz[0] + b->xyz[0]);
out->xyz[1] = 0.5f * (a->xyz[1] + b->xyz[1]);
out->xyz[2] = 0.5f * (a->xyz[2] + b->xyz[2]);
out->st[0] = 0.5f * (a->st[0] + b->st[0]);
out->st[1] = 0.5f * (a->st[1] + b->st[1]);
out->lightmap[0] = 0.5f * (a->lightmap[0] + b->lightmap[0]);
out->lightmap[1] = 0.5f * (a->lightmap[1] + b->lightmap[1]);
out->color[0] = (a->color[0] + b->color[0]) >> 1;
out->color[1] = (a->color[1] + b->color[1]) >> 1;
out->color[2] = (a->color[2] + b->color[2]) >> 1;
out->color[3] = (a->color[3] + b->color[3]) >> 1;
}
/*
============
Transpose
============
*/
static void Transpose( int width, int height, drawVert_t ctrl[MAX_GRID_SIZE][MAX_GRID_SIZE] ) {
int i, j;
drawVert_t temp;
if ( width > height ) {
for ( i = 0 ; i < height ; i++ ) {
for ( j = i + 1 ; j < width ; j++ ) {
if ( j < height ) {
// swap the value
temp = ctrl[j][i];
ctrl[j][i] = ctrl[i][j];
ctrl[i][j] = temp;
} else {
// just copy
ctrl[j][i] = ctrl[i][j];
}
}
}
} else {
for ( i = 0 ; i < width ; i++ ) {
for ( j = i + 1 ; j < height ; j++ ) {
if ( j < width ) {
// swap the value
temp = ctrl[i][j];
ctrl[i][j] = ctrl[j][i];
ctrl[j][i] = temp;
} else {
// just copy
ctrl[i][j] = ctrl[j][i];
}
}
}
}
}
/*
=================
MakeMeshNormals
Handles all the complicated wrapping and degenerate cases
=================
*/
static void MakeMeshNormals( int width, int height, drawVert_t ctrl[MAX_GRID_SIZE][MAX_GRID_SIZE] ) {
int i, j, k, dist;
vec3_t normal;
vec3_t sum;
int count;
vec3_t base;
vec3_t delta;
int x, y;
drawVert_t *dv;
vec3_t around[8], temp;
qboolean good[8];
qboolean wrapWidth, wrapHeight;
float len;
static int neighbors[8][2] = {
{0,1}, {1,1}, {1,0}, {1,-1}, {0,-1}, {-1,-1}, {-1,0}, {-1,1}
};
wrapWidth = qfalse;
for ( i = 0 ; i < height ; i++ ) {
VectorSubtract( ctrl[i][0].xyz, ctrl[i][width-1].xyz, delta );
len = VectorLengthSquared( delta );
if ( len > 1.0 ) {
break;
}
}
if ( i == height ) {
wrapWidth = qtrue;
}
wrapHeight = qfalse;
for ( i = 0 ; i < width ; i++ ) {
VectorSubtract( ctrl[0][i].xyz, ctrl[height-1][i].xyz, delta );
len = VectorLengthSquared( delta );
if ( len > 1.0 ) {
break;
}
}
if ( i == width) {
wrapHeight = qtrue;
}
for ( i = 0 ; i < width ; i++ ) {
for ( j = 0 ; j < height ; j++ ) {
count = 0;
dv = &ctrl[j][i];
VectorCopy( dv->xyz, base );
for ( k = 0 ; k < 8 ; k++ ) {
VectorClear( around[k] );
good[k] = qfalse;
for ( dist = 1 ; dist <= 3 ; dist++ ) {
x = i + neighbors[k][0] * dist;
y = j + neighbors[k][1] * dist;
if ( wrapWidth ) {
if ( x < 0 ) {
x = width - 1 + x;
} else if ( x >= width ) {
x = 1 + x - width;
}
}
if ( wrapHeight ) {
if ( y < 0 ) {
y = height - 1 + y;
} else if ( y >= height ) {
y = 1 + y - height;
}
}
if ( x < 0 || x >= width || y < 0 || y >= height ) {
break; // edge of patch
}
VectorSubtract( ctrl[y][x].xyz, base, temp );
if ( VectorNormalize2( temp, temp ) == 0 ) {
continue; // degenerate edge, get more dist
} else {
good[k] = qtrue;
VectorCopy( temp, around[k] );
break; // good edge
}
}
}
VectorClear( sum );
for ( k = 0 ; k < 8 ; k++ ) {
if ( !good[k] || !good[(k+1)&7] ) {
continue; // didn't get two points
}
CrossProduct( around[(k+1)&7], around[k], normal );
if ( VectorNormalize2( normal, normal ) == 0 ) {
continue;
}
VectorAdd( normal, sum, sum );
count++;
}
if ( count == 0 ) {
//printf("bad normal\n");
count = 1;
}
VectorNormalize2( sum, dv->normal );
}
}
}
/*
============
InvertCtrl
============
*/
static void InvertCtrl( int width, int height, drawVert_t ctrl[MAX_GRID_SIZE][MAX_GRID_SIZE] ) {
int i, j;
drawVert_t temp;
for ( i = 0 ; i < height ; i++ ) {
for ( j = 0 ; j < width/2 ; j++ ) {
temp = ctrl[i][j];
ctrl[i][j] = ctrl[i][width-1-j];
ctrl[i][width-1-j] = temp;
}
}
}
/*
=================
InvertErrorTable
=================
*/
static void InvertErrorTable( float errorTable[2][MAX_GRID_SIZE], int width, int height ) {
int i;
float copy[2][MAX_GRID_SIZE];
Com_Memcpy( copy, errorTable, sizeof( copy ) );
for ( i = 0 ; i < width ; i++ ) {
errorTable[1][i] = copy[0][i]; //[width-1-i];
}
for ( i = 0 ; i < height ; i++ ) {
errorTable[0][i] = copy[1][height-1-i];
}
}
/*
==================
PutPointsOnCurve
==================
*/
static void PutPointsOnCurve( drawVert_t ctrl[MAX_GRID_SIZE][MAX_GRID_SIZE],
int width, int height ) {
int i, j;
drawVert_t prev, next;
for ( i = 0 ; i < width ; i++ ) {
for ( j = 1 ; j < height ; j += 2 ) {
LerpDrawVert( &ctrl[j][i], &ctrl[j+1][i], &prev );
LerpDrawVert( &ctrl[j][i], &ctrl[j-1][i], &next );
LerpDrawVert( &prev, &next, &ctrl[j][i] );
}
}
for ( j = 0 ; j < height ; j++ ) {
for ( i = 1 ; i < width ; i += 2 ) {
LerpDrawVert( &ctrl[j][i], &ctrl[j][i+1], &prev );
LerpDrawVert( &ctrl[j][i], &ctrl[j][i-1], &next );
LerpDrawVert( &prev, &next, &ctrl[j][i] );
}
}
}
/*
=================
R_CreateSurfaceGridMesh
=================
*/
srfGridMesh_t *R_CreateSurfaceGridMesh(int width, int height,
drawVert_t ctrl[MAX_GRID_SIZE][MAX_GRID_SIZE], float errorTable[2][MAX_GRID_SIZE] ) {
int i, j, size;
drawVert_t *vert;
vec3_t tmpVec;
srfGridMesh_t *grid;
// copy the results out to a grid
size = (width * height - 1) * sizeof( drawVert_t ) + sizeof( *grid );
#ifdef PATCH_STITCHING
grid = /*ri.Hunk_Alloc*/ ri.Malloc( size );
Com_Memset(grid, 0, size);
grid->widthLodError = /*ri.Hunk_Alloc*/ ri.Malloc( width * 4 );
Com_Memcpy( grid->widthLodError, errorTable[0], width * 4 );
grid->heightLodError = /*ri.Hunk_Alloc*/ ri.Malloc( height * 4 );
Com_Memcpy( grid->heightLodError, errorTable[1], height * 4 );
#else
grid = ri.Hunk_Alloc( size );
Com_Memset(grid, 0, size);
grid->widthLodError = ri.Hunk_Alloc( width * 4 );
Com_Memcpy( grid->widthLodError, errorTable[0], width * 4 );
grid->heightLodError = ri.Hunk_Alloc( height * 4 );
Com_Memcpy( grid->heightLodError, errorTable[1], height * 4 );
#endif
grid->width = width;
grid->height = height;
grid->surfaceType = SF_GRID;
ClearBounds( grid->meshBounds[0], grid->meshBounds[1] );
for ( i = 0 ; i < width ; i++ ) {
for ( j = 0 ; j < height ; j++ ) {
vert = &grid->verts[j*width+i];
*vert = ctrl[j][i];
AddPointToBounds( vert->xyz, grid->meshBounds[0], grid->meshBounds[1] );
}
}
// compute local origin and bounds
VectorAdd( grid->meshBounds[0], grid->meshBounds[1], grid->localOrigin );
VectorScale( grid->localOrigin, 0.5f, grid->localOrigin );
VectorSubtract( grid->meshBounds[0], grid->localOrigin, tmpVec );
grid->meshRadius = VectorLength( tmpVec );
VectorCopy( grid->localOrigin, grid->lodOrigin );
grid->lodRadius = grid->meshRadius;
//
return grid;
}
/*
=================
R_FreeSurfaceGridMesh
=================
*/
void R_FreeSurfaceGridMesh( srfGridMesh_t *grid ) {
ri.Free(grid->widthLodError);
ri.Free(grid->heightLodError);
ri.Free(grid);
}
/*
=================
R_SubdividePatchToGrid
=================
*/
srfGridMesh_t *R_SubdividePatchToGrid( int width, int height,
drawVert_t points[MAX_PATCH_SIZE*MAX_PATCH_SIZE] ) {
int i, j, k, l;
drawVert_t prev, next, mid;
float len, maxLen;
int dir;
int t;
MAC_STATIC drawVert_t ctrl[MAX_GRID_SIZE][MAX_GRID_SIZE];
float errorTable[2][MAX_GRID_SIZE];
for ( i = 0 ; i < width ; i++ ) {
for ( j = 0 ; j < height ; j++ ) {
ctrl[j][i] = points[j*width+i];
}
}
for ( dir = 0 ; dir < 2 ; dir++ ) {
for ( j = 0 ; j < MAX_GRID_SIZE ; j++ ) {
errorTable[dir][j] = 0;
}
// horizontal subdivisions
for ( j = 0 ; j + 2 < width ; j += 2 ) {
// check subdivided midpoints against control points
// FIXME: also check midpoints of adjacent patches against the control points
// this would basically stitch all patches in the same LOD group together.
maxLen = 0;
for ( i = 0 ; i < height ; i++ ) {
vec3_t midxyz;
vec3_t midxyz2;
vec3_t dir;
vec3_t projected;
float d;
// calculate the point on the curve
for ( l = 0 ; l < 3 ; l++ ) {
midxyz[l] = (ctrl[i][j].xyz[l] + ctrl[i][j+1].xyz[l] * 2
+ ctrl[i][j+2].xyz[l] ) * 0.25f;
}
// see how far off the line it is
// using dist-from-line will not account for internal
// texture warping, but it gives a lot less polygons than
// dist-from-midpoint
VectorSubtract( midxyz, ctrl[i][j].xyz, midxyz );
VectorSubtract( ctrl[i][j+2].xyz, ctrl[i][j].xyz, dir );
VectorNormalize( dir );
d = DotProduct( midxyz, dir );
VectorScale( dir, d, projected );
VectorSubtract( midxyz, projected, midxyz2);
len = VectorLengthSquared( midxyz2 ); // we will do the sqrt later
if ( len > maxLen ) {
maxLen = len;
}
}
maxLen = sqrt(maxLen);
// if all the points are on the lines, remove the entire columns
if ( maxLen < 0.1f ) {
errorTable[dir][j+1] = 999;
continue;
}
// see if we want to insert subdivided columns
if ( width + 2 > MAX_GRID_SIZE ) {
errorTable[dir][j+1] = 1.0f/maxLen;
continue; // can't subdivide any more
}
if ( maxLen <= r_subdivisions->value ) {
errorTable[dir][j+1] = 1.0f/maxLen;
continue; // didn't need subdivision
}
errorTable[dir][j+2] = 1.0f/maxLen;
// insert two columns and replace the peak
width += 2;
for ( i = 0 ; i < height ; i++ ) {
LerpDrawVert( &ctrl[i][j], &ctrl[i][j+1], &prev );
LerpDrawVert( &ctrl[i][j+1], &ctrl[i][j+2], &next );
LerpDrawVert( &prev, &next, &mid );
for ( k = width - 1 ; k > j + 3 ; k-- ) {
ctrl[i][k] = ctrl[i][k-2];
}
ctrl[i][j + 1] = prev;
ctrl[i][j + 2] = mid;
ctrl[i][j + 3] = next;
}
// back up and recheck this set again, it may need more subdivision
j -= 2;
}
Transpose( width, height, ctrl );
t = width;
width = height;
height = t;
}
// put all the aproximating points on the curve
PutPointsOnCurve( ctrl, width, height );
// cull out any rows or columns that are colinear
for ( i = 1 ; i < width-1 ; i++ ) {
if ( errorTable[0][i] != 999 ) {
continue;
}
for ( j = i+1 ; j < width ; j++ ) {
for ( k = 0 ; k < height ; k++ ) {
ctrl[k][j-1] = ctrl[k][j];
}
errorTable[0][j-1] = errorTable[0][j];
}
width--;
}
for ( i = 1 ; i < height-1 ; i++ ) {
if ( errorTable[1][i] != 999 ) {
continue;
}
for ( j = i+1 ; j < height ; j++ ) {
for ( k = 0 ; k < width ; k++ ) {
ctrl[j-1][k] = ctrl[j][k];
}
errorTable[1][j-1] = errorTable[1][j];
}
height--;
}
#if 1
// flip for longest tristrips as an optimization
// the results should be visually identical with or
// without this step
if ( height > width ) {
Transpose( width, height, ctrl );
InvertErrorTable( errorTable, width, height );
t = width;
width = height;
height = t;
InvertCtrl( width, height, ctrl );
}
#endif
// calculate normals
MakeMeshNormals( width, height, ctrl );
return R_CreateSurfaceGridMesh( width, height, ctrl, errorTable );
}
/*
===============
R_GridInsertColumn
===============
*/
srfGridMesh_t *R_GridInsertColumn( srfGridMesh_t *grid, int column, int row, vec3_t point, float loderror ) {
int i, j;
int width, height, oldwidth;
MAC_STATIC drawVert_t ctrl[MAX_GRID_SIZE][MAX_GRID_SIZE];
float errorTable[2][MAX_GRID_SIZE];
float lodRadius;
vec3_t lodOrigin;
oldwidth = 0;
width = grid->width + 1;
if (width > MAX_GRID_SIZE)
return NULL;
height = grid->height;
for (i = 0; i < width; i++) {
if (i == column) {
//insert new column
for (j = 0; j < grid->height; j++) {
LerpDrawVert( &grid->verts[j * grid->width + i-1], &grid->verts[j * grid->width + i], &ctrl[j][i] );
if (j == row)
VectorCopy(point, ctrl[j][i].xyz);
}
errorTable[0][i] = loderror;
continue;
}
errorTable[0][i] = grid->widthLodError[oldwidth];
for (j = 0; j < grid->height; j++) {
ctrl[j][i] = grid->verts[j * grid->width + oldwidth];
}
oldwidth++;
}
for (j = 0; j < grid->height; j++) {
errorTable[1][j] = grid->heightLodError[j];
}
// put all the aproximating points on the curve
//PutPointsOnCurve( ctrl, width, height );
// calculate normals
MakeMeshNormals( width, height, ctrl );
VectorCopy(grid->lodOrigin, lodOrigin);
lodRadius = grid->lodRadius;
// free the old grid
R_FreeSurfaceGridMesh(grid);
// create a new grid
grid = R_CreateSurfaceGridMesh( width, height, ctrl, errorTable );
grid->lodRadius = lodRadius;
VectorCopy(lodOrigin, grid->lodOrigin);
return grid;
}
/*
===============
R_GridInsertRow
===============
*/
srfGridMesh_t *R_GridInsertRow( srfGridMesh_t *grid, int row, int column, vec3_t point, float loderror ) {
int i, j;
int width, height, oldheight;
MAC_STATIC drawVert_t ctrl[MAX_GRID_SIZE][MAX_GRID_SIZE];
float errorTable[2][MAX_GRID_SIZE];
float lodRadius;
vec3_t lodOrigin;
oldheight = 0;
width = grid->width;
height = grid->height + 1;
if (height > MAX_GRID_SIZE)
return NULL;
for (i = 0; i < height; i++) {
if (i == row) {
//insert new row
for (j = 0; j < grid->width; j++) {
LerpDrawVert( &grid->verts[(i-1) * grid->width + j], &grid->verts[i * grid->width + j], &ctrl[i][j] );
if (j == column)
VectorCopy(point, ctrl[i][j].xyz);
}
errorTable[1][i] = loderror;
continue;
}
errorTable[1][i] = grid->heightLodError[oldheight];
for (j = 0; j < grid->width; j++) {
ctrl[i][j] = grid->verts[oldheight * grid->width + j];
}
oldheight++;
}
for (j = 0; j < grid->width; j++) {
errorTable[0][j] = grid->widthLodError[j];
}
// put all the aproximating points on the curve
//PutPointsOnCurve( ctrl, width, height );
// calculate normals
MakeMeshNormals( width, height, ctrl );
VectorCopy(grid->lodOrigin, lodOrigin);
lodRadius = grid->lodRadius;
// free the old grid
R_FreeSurfaceGridMesh(grid);
// create a new grid
grid = R_CreateSurfaceGridMesh( width, height, ctrl, errorTable );
grid->lodRadius = lodRadius;
VectorCopy(lodOrigin, grid->lodOrigin);
return grid;
}