git.hungrycats.org Git - xscreensaver/blob - hacks/bumps.c

   1 /* -*- mode: C; tab-width: 4 -*-
   2  * Bumps, Copyright (c) 2002 Shane Smit <CodeWeaver@DigitalLoom.org>
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that
   7  * copyright notice and this permission notice appear in supporting
   8  * documentation.  No representations are made about the suitability of this
   9  * software for any purpose.  It is provided "as is" without express or
  10  * implied warranty.
  11  *
  12  * Module: "bumps.c"
  13  * Tab Size: 4
  14  *
  15  * Description:
  16  *  This is typical bump-mapping.  The actual bump map is generated by a screen
  17  *  grab.  The light source is represented by a spotlight of random color. This
  18  *  spotlight randomly traverses the bump map in a sinus pattern.
  19  *
  20  *  Essentially, it 3D-izes your desktop, based on color intensity.
  21  *
  22  * Modification History:
  23  *  [10/01/99] - Shane Smit: Creation
  24  *  [10/08/99] - Shane Smit: Port to C. (Ick)
  25  *  [03/08/02] - Shane Smit: New movement code.
  26  *  [09/12/02] - Shane Smit: MIT-SHM XImages.
  27  *                                                       Thanks to Kennett Galbraith <http://www.Alpha-II.com/>
  28  *                                                       for code optimization.
  29  */
  30
  31 #include "bumps.h"
  32
  33 /* This function pointer will point to the appropriate PutPixel*() function below. */
  34 void (*MyPutPixel)( int8_ *, uint32_ );
  35
  36 void PutPixel32( int8_ *pData, uint32_ pixel )
  37 {
  38         *(uint32_ *)pData = pixel;
  39 }
  40
  41 void PutPixel24( int8_ *pData, uint32_ pixel )
  42 {
  43         pData[ 2 ] = ( pixel & 0x00FF0000 ) >> 16;
  44         pData[ 1 ] = ( pixel & 0x0000FF00 ) >> 8;
  45         pData[ 0 ] = ( pixel & 0x000000FF );
  46 }
  47
  48 void PutPixel16( int8_ *pData, uint32_ pixel )
  49 {
  50         *(uint16_ *)pData = (uint16_)pixel;
  51 }
  52
  53 void PutPixel8( int8_ *pData, uint32_ pixel )
  54 {
  55         *(uint8_ *)pData = (uint8_)pixel;
  56 }
  57
  58 /* Creates the light map, which is a circular image... going from black around the edges
  59  * to white in the center. */
  60 void CreateSpotLight( SSpotLight *pSpotLight, uint16_ iDiameter, uint16_ nColorCount )
  61 {
  62         double nDist;
  63         int16_ iDistX, iDistY;
  64         uint8_ *pLOffset;
  65
  66         pSpotLight->nFalloffDiameter = iDiameter;
  67         pSpotLight->nFalloffRadius = pSpotLight->nFalloffDiameter / 2;
  68         pSpotLight->nLightDiameter = iDiameter / 2;
  69         pSpotLight->nLightRadius = pSpotLight->nLightDiameter / 2;
  70 #ifdef VERBOSE
  71         printf( "%s: Falloff Diameter: %d\n", progclass, pSpotLight->nFalloffDiameter );
  72         printf( "%s: Spot Light Diameter: %d\n", progclass, pSpotLight->nLightDiameter );
  73 #endif
  74
  75         pSpotLight->aLightMap = malloc( pSpotLight->nLightDiameter * pSpotLight->nLightDiameter * sizeof(uint8_) );
  76
  77         pLOffset = pSpotLight->aLightMap;
  78         for( iDistY=-pSpotLight->nLightRadius; iDistY<pSpotLight->nLightRadius; ++iDistY )
  79         {
  80                 for( iDistX=-pSpotLight->nLightRadius; iDistX<pSpotLight->nLightRadius; ++iDistX )
  81                 {
  82                         nDist = sqrt( pow( iDistX+0.5F, 2 ) + pow( iDistY+0.5F, 2 ) );
  83                         if( nDist / pSpotLight->nLightRadius <= 1.0f )
  84                                 *pLOffset = (uint8_)(nColorCount - ( ( nDist / pSpotLight->nLightRadius ) * ( nColorCount - 1 ) ));
  85                         else
  86                                 *pLOffset = 0;
  87
  88                         ++pLOffset;
  89                 }
  90         }
  91
  92         /* Initialize movement variables.       */
  93         pSpotLight->nAccelX = 0;
  94         pSpotLight->nAccelY = 0;
  95         pSpotLight->nVelocityX = ( RANDOM() % 2 ) ? pSpotLight->nVelocityMax : -pSpotLight->nVelocityMax;
  96         pSpotLight->nVelocityY = ( RANDOM() % 2 ) ? pSpotLight->nVelocityMax : -pSpotLight->nVelocityMax;
  97 }
  98
  99
 100 /* Calculates the position of the spot light on the screen. */
 101 void CalcLightPos( SBumps *pBumps )
 102 {
 103         SSpotLight *pSpotLight = &pBumps->SpotLight;
 104         float nGravity;
 105
 106         /* X */
 107         if( pSpotLight->nXPos < pSpotLight->nFalloffRadius )                                                    nGravity = 1.0f;
 108         else if( pSpotLight->nXPos > pBumps->iWinWidth - pSpotLight->nFalloffRadius )   nGravity = -1.0f;
 109         else                                                                                                                                                    nGravity = ( ( RANDOM() % 201 ) / 100.0f ) - 1.0f;
 110
 111         pSpotLight->nAccelX += nGravity * ( pSpotLight->nAccelMax / 5.0f );
 112         if( pSpotLight->nAccelX < -pSpotLight->nAccelMax )              pSpotLight->nAccelX = -pSpotLight->nAccelMax;
 113         else if( pSpotLight->nAccelX > pSpotLight->nAccelMax )  pSpotLight->nAccelX = pSpotLight->nAccelMax;
 114
 115         pSpotLight->nVelocityX += pSpotLight->nAccelX;
 116         if( pSpotLight->nVelocityX < -pSpotLight->nVelocityMax )                pSpotLight->nVelocityX = -pSpotLight->nVelocityMax;
 117         else if( pSpotLight->nVelocityX > pSpotLight->nVelocityMax )    pSpotLight->nVelocityX = pSpotLight->nVelocityMax;
 118
 119         pSpotLight->nXPos += pSpotLight->nVelocityX;
 120
 121         /* Y */
 122         if( pSpotLight->nYPos < pSpotLight->nFalloffRadius )                                                            nGravity = 1.0f;
 123         else if( pSpotLight->nYPos > pBumps->iWinHeight - pSpotLight->nFalloffRadius )  nGravity = -1.0f;
 124         else                                                                                                                                                    nGravity = ( ( RANDOM() % 201 ) / 100.0f ) - 1.0f;
 125
 126         pSpotLight->nAccelY += nGravity * ( pSpotLight->nAccelMax / 5.0f );
 127         if( pSpotLight->nAccelY < -pSpotLight->nAccelMax )              pSpotLight->nAccelY = -pSpotLight->nAccelMax;
 128         else if( pSpotLight->nAccelY > pSpotLight->nAccelMax )  pSpotLight->nAccelY = pSpotLight->nAccelMax;
 129
 130         pSpotLight->nVelocityY += pSpotLight->nAccelY;
 131         if( pSpotLight->nVelocityY < -pSpotLight->nVelocityMax )                pSpotLight->nVelocityY = -pSpotLight->nVelocityMax;
 132         else if( pSpotLight->nVelocityY > pSpotLight->nVelocityMax )    pSpotLight->nVelocityY = pSpotLight->nVelocityMax;
 133
 134         pSpotLight->nYPos += pSpotLight->nVelocityY;
 135 }
 136
 137
 138 /* Main initialization function. */
 139 void CreateBumps( SBumps *pBumps, Display *pNewDisplay, Window NewWin )
 140 {
 141         XWindowAttributes XWinAttribs;
 142         XGCValues GCValues;
 143         int32_ nGCFlags;
 144         uint16_ iDiameter;
 145
 146         /* Make size and velocity a function of window size, so it appears the same at 100x60 as it does in 3200x1200. */
 147         XGetWindowAttributes( pNewDisplay, NewWin, &XWinAttribs );
 148         pBumps->iWinWidth = XWinAttribs.width;
 149         pBumps->iWinHeight = XWinAttribs.height;
 150         pBumps->SpotLight.nXPos = XWinAttribs.width / 2.0f;
 151         pBumps->SpotLight.nYPos = XWinAttribs.height / 2.0f;
 152         pBumps->SpotLight.nVelocityMax = ( ( XWinAttribs.width < XWinAttribs.height ) ? XWinAttribs.width : XWinAttribs.height ) / 140.0f;
 153         pBumps->SpotLight.nAccelMax = pBumps->SpotLight.nVelocityMax / 10.0f;
 154         pBumps->pDisplay = pNewDisplay;
 155         pBumps->Win = NewWin;
 156         pBumps->pXImage = NULL;
 157
 158         iDiameter = ( ( pBumps->iWinWidth < pBumps->iWinHeight ) ? pBumps->iWinWidth : pBumps->iWinHeight ) / 2;
 159
 160 #ifdef HAVE_XSHM_EXTENSION
 161         pBumps->bUseShm = get_boolean_resource( "useSHM", "Boolean" );
 162
 163         if( pBumps->bUseShm )
 164         {
 165                 pBumps->pXImage = create_xshm_image( pBumps->pDisplay, XWinAttribs.visual, XWinAttribs.depth,
 166                                                                                          ZPixmap, NULL, &pBumps->XShmInfo, iDiameter, iDiameter );
 167                 if( !pBumps->pXImage )
 168                 {
 169                         fprintf( stderr, "%s: Unable to create XShmImage.\n", progname );
 170                         pBumps->bUseShm = False;
 171                 }
 172         }
 173 #endif /* HAVE_XSHM_EXTENSION */
 174         if( !pBumps->pXImage )
 175         {
 176                 pBumps->pXImage = XCreateImage( pBumps->pDisplay, XWinAttribs.visual, XWinAttribs.depth,
 177                                                                         ZPixmap, 0, NULL, iDiameter, iDiameter, BitmapPad( pBumps->pDisplay ), 0 );
 178                 pBumps->pXImage->data = malloc( pBumps->pXImage->bytes_per_line * pBumps->pXImage->height * sizeof(int8_) );
 179         }
 180
 181         /* For speed, access the XImage data directly using my own PutPixel routine. */
 182         switch( pBumps->pXImage->bits_per_pixel )
 183         {
 184                 case 32:
 185                         pBumps->bytesPerPixel = 4;
 186                         MyPutPixel = PutPixel32;
 187                         break;
 188
 189                 case 24:
 190                         pBumps->bytesPerPixel = 3;
 191                         MyPutPixel = PutPixel24;
 192                         break;
 193
 194                 case 16:
 195                         pBumps->bytesPerPixel = 2;
 196                         MyPutPixel = PutPixel16;
 197                         break;
 198
 199                 case 8:
 200                         pBumps->bytesPerPixel = 1;
 201                         MyPutPixel = PutPixel8;
 202                         break;
 203
 204                 default:
 205                         fprintf( stderr, "%s: Unknown XImage depth.", progname );
 206 #ifdef HAVE_XSHM_EXTENSION
 207                         if( pBumps->bUseShm )
 208                                 destroy_xshm_image( pBumps->pDisplay, pBumps->pXImage, &pBumps->XShmInfo );
 209                         else
 210 #endif /* HAVE_XSHM_EXTENSION */
 211                                 XDestroyImage( pBumps->pXImage );
 212                         exit( 1 );
 213         }
 214
 215         GCValues.function = GXcopy;
 216         GCValues.subwindow_mode = IncludeInferiors;
 217         nGCFlags = GCForeground | GCFunction;
 218         if( use_subwindow_mode_p( XWinAttribs.screen, pBumps->Win ) ) /* See grabscreen.c */
 219                 nGCFlags |= GCSubwindowMode;
 220         pBumps->GraphicsContext = XCreateGC( pBumps->pDisplay, pBumps->Win, nGCFlags, &GCValues );
 221
 222         SetPalette( pBumps, &XWinAttribs );
 223         CreateSpotLight( &pBumps->SpotLight, iDiameter, pBumps->nColorCount );
 224         InitBumpMap( pBumps, &XWinAttribs );
 225
 226         XSetWindowBackground( pBumps->pDisplay, pBumps->Win, pBumps->aColors[ 0 ] );
 227         XClearWindow (pBumps->pDisplay, pBumps->Win);
 228 }
 229
 230
 231 /* Creates a specialized phong shade palette. */
 232 void SetPalette( SBumps *pBumps, XWindowAttributes *pXWinAttribs )
 233 {
 234         XColor BaseColor;
 235         XColor Color;
 236         char *sColor;                   /* Spotlight Color */
 237         int16_ iColor;
 238
 239         sColor = get_string_resource( "color", "Color" );
 240
 241         BaseColor.red = RANDOM() % 0xFFFF;
 242         BaseColor.green = RANDOM() % 0xFFFF;
 243         BaseColor.blue = RANDOM() % 0xFFFF;
 244
 245         /* Make one color full intesity to avoid dark spotlights.       */
 246         switch( RANDOM() % 3 )
 247         {
 248                 case 0: BaseColor.red   = 0xFFFF;       break;
 249                 case 1: BaseColor.green = 0xFFFF;       break;
 250                 case 2: BaseColor.blue  = 0xFFFF;       break;
 251         }
 252
 253         if( strcasecmp( sColor, "random" ) && !XParseColor( pBumps->pDisplay, pXWinAttribs->colormap, sColor, &BaseColor ) )
 254                 fprintf( stderr, "%s: color %s not found in database. Choosing random...\n", progname, sColor );
 255
 256 #ifdef VERBOSE
 257         printf( "%s: Spotlight color is <%d,%d,%d> RGB.\n", progclass, BaseColor.red, BaseColor.green, BaseColor.blue );
 258 #endif  /*  VERBOSE */
 259
 260         pBumps->nColorCount = get_integer_resource( "colorcount", "Integer" );
 261         if( pBumps->nColorCount < 2 )   pBumps->nColorCount = 2;
 262         if( pBumps->nColorCount > 128 ) pBumps->nColorCount = 128;
 263
 264         pBumps->aColors = malloc( pBumps->nColorCount * sizeof(uint32_ ) );
 265
 266         /* Creates a phong shade:                 / BaseColor  \                               Index/ColorCount
 267          *                                                      PhongShade = | ------------ | Index + ( 65535 - BaseColor )^
 268          *                                                                                \ ColorCount /                                                                                                */
 269         pBumps->nColorCount--;
 270         for( iColor=0; iColor<=pBumps->nColorCount; iColor++ )
 271         {
 272                 Color.red   = (uint16_)( ( ( BaseColor.red   / (double)pBumps->nColorCount ) * iColor ) + pow( 0xFFFF - BaseColor.red,   iColor/(double)pBumps->nColorCount ) );
 273                 Color.green = (uint16_)( ( ( BaseColor.green / (double)pBumps->nColorCount ) * iColor ) + pow( 0xFFFF - BaseColor.green, iColor/(double)pBumps->nColorCount ) );
 274                 Color.blue  = (uint16_)( ( ( BaseColor.blue  / (double)pBumps->nColorCount ) * iColor ) + pow( 0xFFFF - BaseColor.blue,  iColor/(double)pBumps->nColorCount ) );
 275
 276                 if( !XAllocColor( pBumps->pDisplay, pXWinAttribs->colormap, &Color ) )
 277                 {
 278                         XFreeColors( pBumps->pDisplay, pXWinAttribs->colormap, pBumps->aColors, iColor, 0 );
 279                         free( pBumps->aColors );
 280                         pBumps->aColors = malloc( pBumps->nColorCount * sizeof(uint32_) );
 281                         pBumps->nColorCount--;
 282                         iColor = -1;
 283                 }
 284                 else
 285                         pBumps->aColors[ iColor ] = Color.pixel;
 286         }
 287         pBumps->nColorCount++;
 288
 289 #ifdef VERBOSE
 290         printf( "%s: Allocated %d colors.\n", progclass, pBumps->nColorCount );
 291 #endif  /*  VERBOSE */
 292
 293         XSetWindowBackground( pBumps->pDisplay, pBumps->Win, pBumps->aColors[ 0 ] );
 294 }
 295
 296
 297 /* Grabs the current contents of the window to use an intensity-based bump map. */
 298 void InitBumpMap( SBumps *pBumps, XWindowAttributes *pXWinAttribs )
 299 {
 300         XImage *pScreenImage;
 301         XColor *aColors, *pColor;
 302         uint8_ nSoften;
 303         uint16_ iWidth, iHeight;
 304         uint32_ nAverager;
 305         uint16_ *pBump;
 306         uint16_ maxHeight;
 307         double softenMultiplier = 1.0f;
 308         BOOL bInvert = (BOOL)get_boolean_resource( "invert", "Boolean" );
 309     Pixmap p;
 310
 311         aColors = (XColor*)malloc( pBumps->iWinWidth * sizeof(XColor) );
 312
 313     p = XCreatePixmap(pBumps->pDisplay, pBumps->Win,
 314                       pXWinAttribs->width, pXWinAttribs->height,
 315                       pXWinAttribs->depth);
 316     load_random_image (pXWinAttribs->screen, pBumps->Win, p);
 317
 318         pScreenImage = XGetImage( pBumps->pDisplay, p, 0, 0, pBumps->iWinWidth, pBumps->iWinHeight, ~0L, ZPixmap );
 319     XFreePixmap (pBumps->pDisplay, p);
 320
 321         /* jwz: get the grabbed bits off the screen fast */
 322         XClearWindow (pBumps->pDisplay, pBumps->Win);
 323         XSync (pBumps->pDisplay, 0);
 324
 325         pBumps->aBumpMap = malloc( pBumps->iWinWidth * pBumps->iWinHeight * sizeof(uint16_) );
 326
 327         nSoften = get_integer_resource( "soften", "Integer" );
 328         while( nSoften-- )
 329                 softenMultiplier *= 1.0f + ( 1.0f / 3.0f );     /* Softening takes the max height down, so scale up to compensate. */
 330         maxHeight = pBumps->SpotLight.nLightRadius * softenMultiplier;
 331         nAverager = ( 3 * 0xFFFF ) / maxHeight;
 332
 333         pBump = pBumps->aBumpMap;
 334         if( bInvert )   /* Funny, it's actually the 'else' that inverts the bump map... */
 335         {
 336                 for( iHeight=0; iHeight<pBumps->iWinHeight; iHeight++ )
 337                 {
 338                         pColor = aColors;
 339                         for( iWidth=0; iWidth<pBumps->iWinWidth; iWidth++ )
 340                                 (pColor++)->pixel = XGetPixel( pScreenImage, iWidth, iHeight );
 341
 342                         XQueryColors( pBumps->pDisplay, pXWinAttribs->colormap, aColors, pBumps->iWinWidth );
 343
 344                         pColor = aColors;
 345                         for( iWidth=pBumps->iWinWidth; iWidth; --iWidth, ++pColor, ++pBump )
 346                                 *pBump = ( ( pColor->red + pColor->green + pColor->blue ) / nAverager );
 347                 }
 348         }
 349         else
 350         {
 351                 for( iHeight=0; iHeight<pBumps->iWinHeight; iHeight++ )
 352                 {
 353                         pColor = aColors;
 354                         for( iWidth=0; iWidth<pBumps->iWinWidth; iWidth++ )
 355                                 (pColor++)->pixel = XGetPixel( pScreenImage, iWidth, iHeight );
 356
 357                         XQueryColors( pBumps->pDisplay, pXWinAttribs->colormap, aColors, pBumps->iWinWidth );
 358
 359                         pColor = aColors;
 360                         for( iWidth=pBumps->iWinWidth; iWidth; --iWidth, ++pColor, ++pBump )
 361                                 *pBump = ( maxHeight - ( ( pColor->red + pColor->green + pColor->blue ) / nAverager ) );
 362                 }
 363         }
 364
 365         XDestroyImage( pScreenImage );
 366
 367         nSoften = get_integer_resource( "soften", "Integer" );
 368 #ifdef VERBOSE
 369         if( nSoften )   printf( "%s: Softening Bump Map %d time(s)...\n", progclass, nSoften );
 370 #endif
 371         while( nSoften-- )
 372                 SoftenBumpMap( pBumps );
 373
 374         free( aColors );
 375 }
 376
 377 /* Soften the bump map.  This is to avoid pixellated-looking ridges.
 378  * |-----|-----|-----|
 379  * |  0% |12.5%|  0% |  The adjacent pixels are averaged together
 380  * |-----|-----|-----|  first.  Then than value is averaged with
 381  * |12.5%| 50% |12.5%|  the pixel is question. This essentially weights
 382  * |-----|-----|-----|  each pixel as shown on the left.
 383  * |  0% |12.5%|  0% |
 384  * |-----|-----|-----|
 385  */
 386 void SoftenBumpMap( SBumps *pBumps )
 387 {
 388         uint16_ *pOffset, *pTOffset;
 389         uint32_ nHeight;
 390         uint32_ iWidth, iHeight;
 391         uint16_ *aTempBuffer = malloc( pBumps->iWinWidth * pBumps->iWinHeight * sizeof(uint16_) );
 392
 393         pOffset = pBumps->aBumpMap;
 394         pTOffset = aTempBuffer;
 395         for( iHeight=pBumps->iWinHeight; iHeight; --iHeight )
 396         {
 397                 for( iWidth=pBumps->iWinWidth; iWidth; --iWidth, ++pOffset, ++pTOffset )
 398                 {
 399                         if( iHeight==pBumps->iWinHeight || iHeight==1 ||
 400                                 iWidth==pBumps->iWinWidth || iWidth==1 )
 401                         {
 402                                 *pTOffset = 0;
 403                                 continue;
 404                         }
 405
 406                         nHeight = pOffset[ -pBumps->iWinWidth ];
 407                         nHeight += pOffset[ 1 ];
 408                         nHeight += pOffset[ pBumps->iWinWidth ];
 409                         nHeight += pOffset[ -1 ];
 410                         nHeight >>= 2;
 411                         nHeight += pOffset[ 0 ];
 412                         nHeight >>= 1;
 413                         *pTOffset = nHeight;
 414                 }
 415         }
 416
 417         memcpy( pBumps->aBumpMap, aTempBuffer, pBumps->iWinWidth * pBumps->iWinHeight * sizeof(uint16_) );
 418         free( aTempBuffer );
 419 }
 420
 421
 422 /* This is where we slap down some pixels... */
 423 void Execute( SBumps *pBumps )
 424 {
 425         int32_ nLightXPos, nLightYPos;
 426         int32_ iScreenX, iScreenY;
 427         int32_ iLightX, iLightY;
 428         uint16_ *pBOffset;
 429         int8_ *pDOffset;
 430         int32_ nX, nY;
 431         uint16_ nColor;
 432         int32_ nLightOffsetFar = pBumps->SpotLight.nFalloffDiameter - pBumps->SpotLight.nLightRadius;
 433
 434         CalcLightPos( pBumps );
 435
 436         /* Offset to upper left hand corner. */
 437         nLightXPos = pBumps->SpotLight.nXPos - pBumps->SpotLight.nFalloffRadius;
 438         nLightYPos = pBumps->SpotLight.nYPos - pBumps->SpotLight.nFalloffRadius;
 439
 440         for( iScreenY=nLightYPos, iLightY=-pBumps->SpotLight.nLightRadius; iLightY<nLightOffsetFar; ++iScreenY, ++iLightY )
 441         {
 442                 if( iScreenY < 0 )                                                      continue;
 443                 else if( iScreenY >= pBumps->iWinHeight )       break;
 444
 445                 pDOffset = &pBumps->pXImage->data[ (iLightY+pBumps->SpotLight.nLightRadius) * pBumps->pXImage->bytes_per_line ];
 446                 pBOffset = pBumps->aBumpMap + ( iScreenY * pBumps->iWinWidth ) + nLightXPos;
 447                 for( iScreenX=nLightXPos, iLightX=-pBumps->SpotLight.nLightRadius; iLightX<nLightOffsetFar; ++iScreenX, ++iLightX, ++pBOffset, pDOffset+=pBumps->bytesPerPixel )
 448                 {
 449                         if( iScreenX < 0 )                                                      continue;
 450                         else if( iScreenX >= pBumps->iWinWidth )        break;
 451                         else if( iScreenY == 0 || iScreenY >= pBumps->iWinHeight-2 ||
 452                                          iScreenX == 0 || iScreenX >= pBumps->iWinWidth-2 )
 453                         {
 454                                 MyPutPixel( pDOffset, pBumps->aColors[ 0 ] );
 455                                 continue;
 456                         }
 457
 458                         /* That's right folks, all the magic of bump mapping occurs in these two lines.  (kinda disappointing, isn't it?) */
 459                         nX = ( pBOffset[ 1 ] - pBOffset[ 0 ] ) + iLightX;
 460                         nY = ( pBOffset[ pBumps->iWinWidth ] - pBOffset[ 0 ] ) + iLightY;
 461
 462                         if( nX<0 || nX>=pBumps->SpotLight.nLightDiameter
 463                          || nY<0 || nY>=pBumps->SpotLight.nLightDiameter )
 464                         {
 465                                 MyPutPixel( pDOffset, pBumps->aColors[ 0 ] );
 466                                 continue;
 467                         }
 468
 469                         nColor = pBumps->SpotLight.aLightMap[ ( nY * pBumps->SpotLight.nLightDiameter ) + nX ];
 470                         MyPutPixel( pDOffset, pBumps->aColors[ nColor ] );
 471                 }
 472         }
 473
 474         /* Allow the spotlight to go *slightly* off the screen by clipping the XImage. */
 475         iLightX = iLightY = 0;  /* Use these for XImages X and Y now.   */
 476         nX = nY = pBumps->SpotLight.nFalloffDiameter;   /* Use these for XImage width and height now.   */
 477         if( nLightXPos < 0 )
 478         {
 479                 iLightX = -nLightXPos;
 480                 nX -= iLightX;
 481                 nLightXPos = 0;
 482         }
 483         else if( nLightXPos + nX >= pBumps->iWinWidth )
 484         {
 485                 nX -= ( nLightXPos + nX ) - pBumps->iWinWidth;
 486         }
 487
 488         if( nLightYPos < 0 )
 489         {
 490                 iLightY = -nLightYPos;
 491                 nY -= iLightY;
 492                 nLightYPos = 0;
 493         }
 494         else if( nLightYPos + nY >= pBumps->iWinHeight )
 495         {
 496                 nY -= ( nLightYPos + nY ) - pBumps->iWinHeight;
 497         }
 498
 499 #ifdef HAVE_XSHM_EXTENSION
 500         if( pBumps->bUseShm )
 501                 XShmPutImage( pBumps->pDisplay, pBumps->Win, pBumps->GraphicsContext, pBumps->pXImage, iLightX, iLightY, nLightXPos, nLightYPos,
 502                                           nX, nY, False);
 503         else
 504 #endif /* HAVE_XSHM_EXTENSION */
 505                 XPutImage( pBumps->pDisplay, pBumps->Win, pBumps->GraphicsContext, pBumps->pXImage, iLightX, iLightY, nLightXPos, nLightYPos,
 506                                    nX, nY );
 507
 508         XSync( pBumps->pDisplay, False );
 509 }
 510
 511
 512 /* Clean up */
 513 void DestroyBumps( SBumps *pBumps )
 514 {
 515         DestroySpotLight( &pBumps->SpotLight );
 516         free( pBumps->aColors );
 517         free( pBumps->aBumpMap );
 518 #ifdef HAVE_XSHM_EXTENSION
 519         if( pBumps->bUseShm )
 520                 destroy_xshm_image( pBumps->pDisplay, pBumps->pXImage, &pBumps->XShmInfo );
 521         else
 522 #endif /* HAVE_XSHM_EXTENSION */
 523                 XDestroyImage( pBumps->pXImage );
 524 }
 525
 526
 527 /* All messages to the screensaver are processed here. */
 528 void screenhack( Display *pDisplay, Window Win )
 529 {
 530         SBumps Bumps;
 531         uint32_ iDelay;
 532 #ifdef VERBOSE
 533         time_t Time = time( NULL );
 534         uint16_ iFrame = 0;
 535 #endif  /*  VERBOSE */
 536
 537         CreateBumps( &Bumps, pDisplay, Win );
 538         iDelay = get_integer_resource( "delay", "Integer" );
 539
 540         while( 1 )
 541         {
 542                 screenhack_handle_events( pDisplay );
 543                 Execute( &Bumps );
 544                 usleep( iDelay );
 545
 546 #ifdef VERBOSE
 547                 iFrame++;
 548                 if( Time - time( NULL ) )
 549                 {
 550                         printf( "FPS: %d\n", iFrame );
 551                         Time = time( NULL );
 552                         iFrame = 0;
 553                 }
 554 #endif  /*  VERBOSE */
 555         }
 556
 557         DestroyBumps( &Bumps );
 558 }
 559
 560
 561 /* vim: ts=4
 562  */