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Diffstat (limited to 'src/renderer/tr_flares.c')
| -rw-r--r-- | src/renderer/tr_flares.c | 530 |
1 files changed, 530 insertions, 0 deletions
diff --git a/src/renderer/tr_flares.c b/src/renderer/tr_flares.c new file mode 100644 index 0000000..f8fb222 --- /dev/null +++ b/src/renderer/tr_flares.c @@ -0,0 +1,530 @@ +/* +=========================================================================== +Copyright (C) 1999-2005 Id Software, Inc. +Copyright (C) 2000-2006 Tim Angus + +This file is part of Tremulous. + +Tremulous 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. + +Tremulous 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 Tremulous; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +=========================================================================== +*/ +// tr_flares.c + +#include "tr_local.h" + +/* +============================================================================= + +LIGHT FLARES + +A light flare is an effect that takes place inside the eye when bright light +sources are visible. The size of the flare reletive to the screen is nearly +constant, irrespective of distance, but the intensity should be proportional to the +projected area of the light source. + +A surface that has been flagged as having a light flare will calculate the depth +buffer value that it's midpoint should have when the surface is added. + +After all opaque surfaces have been rendered, the depth buffer is read back for +each flare in view. If the point has not been obscured by a closer surface, the +flare should be drawn. + +Surfaces that have a repeated texture should never be flagged as flaring, because +there will only be a single flare added at the midpoint of the polygon. + +To prevent abrupt popping, the intensity of the flare is interpolated up and +down as it changes visibility. This involves scene to scene state, unlike almost +all other aspects of the renderer, and is complicated by the fact that a single +frame may have multiple scenes. + +RB_RenderFlares() will be called once per view (twice in a mirrored scene, potentially +up to five or more times in a frame with 3D status bar icons). + +============================================================================= +*/ + + +// flare states maintain visibility over multiple frames for fading +// layers: view, mirror, menu +typedef struct flare_s { + struct flare_s *next; // for active chain + + int addedFrame; + + qboolean inPortal; // true if in a portal view of the scene + int frameSceneNum; + void *surface; + int fogNum; + + int fadeTime; + + qboolean visible; // state of last test + float drawIntensity; // may be non 0 even if !visible due to fading + + int windowX, windowY; + float eyeZ; + + vec3_t origin; + vec3_t color; +} flare_t; + +#define MAX_FLARES 128 + +flare_t r_flareStructs[MAX_FLARES]; +flare_t *r_activeFlares, *r_inactiveFlares; + +int flareCoeff; + +/* +================== +R_ClearFlares +================== +*/ +void R_ClearFlares( void ) { + int i; + + Com_Memset( r_flareStructs, 0, sizeof( r_flareStructs ) ); + r_activeFlares = NULL; + r_inactiveFlares = NULL; + + for ( i = 0 ; i < MAX_FLARES ; i++ ) { + r_flareStructs[i].next = r_inactiveFlares; + r_inactiveFlares = &r_flareStructs[i]; + } +} + + +/* +================== +RB_AddFlare + +This is called at surface tesselation time +================== +*/ +void RB_AddFlare( void *surface, int fogNum, vec3_t point, vec3_t color, vec3_t normal ) { + int i; + flare_t *f, *oldest; + vec3_t local; + float d = 1; + vec4_t eye, clip, normalized, window; + + backEnd.pc.c_flareAdds++; + + if(normal && (normal[0] || normal[1] || normal[2])) + { + VectorSubtract( backEnd.viewParms.or.origin, point, local ); + VectorNormalizeFast(local); + d = DotProduct(local, normal); + + // If the viewer is behind the flare don't add it. + if(d < 0) + return; + } + + // if the point is off the screen, don't bother adding it + // calculate screen coordinates and depth + R_TransformModelToClip( point, backEnd.or.modelMatrix, + backEnd.viewParms.projectionMatrix, eye, clip ); + + // check to see if the point is completely off screen + for ( i = 0 ; i < 3 ; i++ ) { + if ( clip[i] >= clip[3] || clip[i] <= -clip[3] ) { + return; + } + } + + R_TransformClipToWindow( clip, &backEnd.viewParms, normalized, window ); + + if ( window[0] < 0 || window[0] >= backEnd.viewParms.viewportWidth + || window[1] < 0 || window[1] >= backEnd.viewParms.viewportHeight ) { + return; // shouldn't happen, since we check the clip[] above, except for FP rounding + } + + // see if a flare with a matching surface, scene, and view exists + oldest = r_flareStructs; + for ( f = r_activeFlares ; f ; f = f->next ) { + if ( f->surface == surface && f->frameSceneNum == backEnd.viewParms.frameSceneNum + && f->inPortal == backEnd.viewParms.isPortal ) { + break; + } + } + + // allocate a new one + if (!f ) { + if ( !r_inactiveFlares ) { + // the list is completely full + return; + } + f = r_inactiveFlares; + r_inactiveFlares = r_inactiveFlares->next; + f->next = r_activeFlares; + r_activeFlares = f; + + f->surface = surface; + f->frameSceneNum = backEnd.viewParms.frameSceneNum; + f->inPortal = backEnd.viewParms.isPortal; + f->addedFrame = -1; + } + + if ( f->addedFrame != backEnd.viewParms.frameCount - 1 ) { + f->visible = qfalse; + f->fadeTime = backEnd.refdef.time - 2000; + } + + f->addedFrame = backEnd.viewParms.frameCount; + f->fogNum = fogNum; + + VectorCopy(point, f->origin); + VectorCopy( color, f->color ); + + // fade the intensity of the flare down as the + // light surface turns away from the viewer + VectorScale( f->color, d, f->color ); + + // save info needed to test + f->windowX = backEnd.viewParms.viewportX + window[0]; + f->windowY = backEnd.viewParms.viewportY + window[1]; + + f->eyeZ = eye[2]; +} + +/* +================== +RB_AddDlightFlares +================== +*/ +void RB_AddDlightFlares( void ) { + dlight_t *l; + int i, j, k; + fog_t *fog = NULL; + + if ( !r_flares->integer ) { + return; + } + + l = backEnd.refdef.dlights; + + if(tr.world) + fog = tr.world->fogs; + + for (i=0 ; i<backEnd.refdef.num_dlights ; i++, l++) { + + if(fog) + { + // find which fog volume the light is in + for ( j = 1 ; j < tr.world->numfogs ; j++ ) { + fog = &tr.world->fogs[j]; + for ( k = 0 ; k < 3 ; k++ ) { + if ( l->origin[k] < fog->bounds[0][k] || l->origin[k] > fog->bounds[1][k] ) { + break; + } + } + if ( k == 3 ) { + break; + } + } + if ( j == tr.world->numfogs ) { + j = 0; + } + } + else + j = 0; + + RB_AddFlare( (void *)l, j, l->origin, l->color, NULL ); + } +} + +/* +=============================================================================== + +FLARE BACK END + +=============================================================================== +*/ + +/* +================== +RB_TestFlare +================== +*/ +void RB_TestFlare( flare_t *f ) { + float depth; + qboolean visible; + float fade; + float screenZ; + + backEnd.pc.c_flareTests++; + + // doing a readpixels is as good as doing a glFinish(), so + // don't bother with another sync + glState.finishCalled = qfalse; + + // read back the z buffer contents + qglReadPixels( f->windowX, f->windowY, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &depth ); + + screenZ = backEnd.viewParms.projectionMatrix[14] / + ( ( 2*depth - 1 ) * backEnd.viewParms.projectionMatrix[11] - backEnd.viewParms.projectionMatrix[10] ); + + visible = ( -f->eyeZ - -screenZ ) < 24; + + if ( visible ) { + if ( !f->visible ) { + f->visible = qtrue; + f->fadeTime = backEnd.refdef.time - 1; + } + fade = ( ( backEnd.refdef.time - f->fadeTime ) /1000.0f ) * r_flareFade->value; + } else { + if ( f->visible ) { + f->visible = qfalse; + f->fadeTime = backEnd.refdef.time - 1; + } + fade = 1.0f - ( ( backEnd.refdef.time - f->fadeTime ) / 1000.0f ) * r_flareFade->value; + } + + if ( fade < 0 ) { + fade = 0; + } + if ( fade > 1 ) { + fade = 1; + } + + f->drawIntensity = fade; +} + + +/* +================== +RB_RenderFlare +================== +*/ +void RB_RenderFlare( flare_t *f ) { + float size; + vec3_t color; + int iColor[3]; + float distance, intensity, factor; + byte fogFactors[3] = {255, 255, 255}; + + backEnd.pc.c_flareRenders++; + + // We don't want too big values anyways when dividing by distance. + if(f->eyeZ > -1.0f) + distance = 1.0f; + else + distance = -f->eyeZ; + + // calculate the flare size.. + size = backEnd.viewParms.viewportWidth * ( r_flareSize->value/640.0f + 8 / distance ); + +/* + * This is an alternative to intensity scaling. It changes the size of the flare on screen instead + * with growing distance. See in the description at the top why this is not the way to go. + // size will change ~ 1/r. + size = backEnd.viewParms.viewportWidth * (r_flareSize->value / (distance * -2.0f)); +*/ + +/* + * As flare sizes stay nearly constant with increasing distance we must decrease the intensity + * to achieve a reasonable visual result. The intensity is ~ (size^2 / distance^2) which can be + * got by considering the ratio of + * (flaresurface on screen) : (Surface of sphere defined by flare origin and distance from flare) + * An important requirement is: + * intensity <= 1 for all distances. + * + * The formula used here to compute the intensity is as follows: + * intensity = flareCoeff * size^2 / (distance + size*sqrt(flareCoeff))^2 + * As you can see, the intensity will have a max. of 1 when the distance is 0. + * The coefficient flareCoeff will determine the falloff speed with increasing distance. + */ + + factor = distance + size * sqrt(flareCoeff); + + intensity = flareCoeff * size * size / (factor * factor); + + VectorScale(f->color, f->drawIntensity * intensity, color); + +// Calculations for fogging + if(tr.world && f->fogNum < tr.world->numfogs) + { + tess.numVertexes = 1; + VectorCopy(f->origin, tess.xyz[0]); + tess.fogNum = f->fogNum; + + RB_CalcModulateColorsByFog(fogFactors); + + // We don't need to render the flare if colors are 0 anyways. + if(!(fogFactors[0] || fogFactors[1] || fogFactors[2])) + return; + } + + iColor[0] = color[0] * fogFactors[0]; + iColor[1] = color[1] * fogFactors[1]; + iColor[2] = color[2] * fogFactors[2]; + + RB_BeginSurface( tr.flareShader, f->fogNum ); + + // FIXME: use quadstamp? + tess.xyz[tess.numVertexes][0] = f->windowX - size; + tess.xyz[tess.numVertexes][1] = f->windowY - size; + tess.texCoords[tess.numVertexes][0][0] = 0; + tess.texCoords[tess.numVertexes][0][1] = 0; + tess.vertexColors[tess.numVertexes][0] = iColor[0]; + tess.vertexColors[tess.numVertexes][1] = iColor[1]; + tess.vertexColors[tess.numVertexes][2] = iColor[2]; + tess.vertexColors[tess.numVertexes][3] = 255; + tess.numVertexes++; + + tess.xyz[tess.numVertexes][0] = f->windowX - size; + tess.xyz[tess.numVertexes][1] = f->windowY + size; + tess.texCoords[tess.numVertexes][0][0] = 0; + tess.texCoords[tess.numVertexes][0][1] = 1; + tess.vertexColors[tess.numVertexes][0] = iColor[0]; + tess.vertexColors[tess.numVertexes][1] = iColor[1]; + tess.vertexColors[tess.numVertexes][2] = iColor[2]; + tess.vertexColors[tess.numVertexes][3] = 255; + tess.numVertexes++; + + tess.xyz[tess.numVertexes][0] = f->windowX + size; + tess.xyz[tess.numVertexes][1] = f->windowY + size; + tess.texCoords[tess.numVertexes][0][0] = 1; + tess.texCoords[tess.numVertexes][0][1] = 1; + tess.vertexColors[tess.numVertexes][0] = iColor[0]; + tess.vertexColors[tess.numVertexes][1] = iColor[1]; + tess.vertexColors[tess.numVertexes][2] = iColor[2]; + tess.vertexColors[tess.numVertexes][3] = 255; + tess.numVertexes++; + + tess.xyz[tess.numVertexes][0] = f->windowX + size; + tess.xyz[tess.numVertexes][1] = f->windowY - size; + tess.texCoords[tess.numVertexes][0][0] = 1; + tess.texCoords[tess.numVertexes][0][1] = 0; + tess.vertexColors[tess.numVertexes][0] = iColor[0]; + tess.vertexColors[tess.numVertexes][1] = iColor[1]; + tess.vertexColors[tess.numVertexes][2] = iColor[2]; + tess.vertexColors[tess.numVertexes][3] = 255; + tess.numVertexes++; + + tess.indexes[tess.numIndexes++] = 0; + tess.indexes[tess.numIndexes++] = 1; + tess.indexes[tess.numIndexes++] = 2; + tess.indexes[tess.numIndexes++] = 0; + tess.indexes[tess.numIndexes++] = 2; + tess.indexes[tess.numIndexes++] = 3; + + RB_EndSurface(); +} + +/* +================== +RB_RenderFlares + +Because flares are simulating an occular effect, they should be drawn after +everything (all views) in the entire frame has been drawn. + +Because of the way portals use the depth buffer to mark off areas, the +needed information would be lost after each view, so we are forced to draw +flares after each view. + +The resulting artifact is that flares in mirrors or portals don't dim properly +when occluded by something in the main view, and portal flares that should +extend past the portal edge will be overwritten. +================== +*/ +void RB_RenderFlares (void) { + flare_t *f; + flare_t **prev; + qboolean draw; + + if ( !r_flares->integer ) { + return; + } + + if(r_flareCoeff->modified) + { + if(r_flareCoeff->value == 0.0f) + flareCoeff = atof(FLARE_STDCOEFF); + else + flareCoeff = r_flareCoeff->value; + + r_flareCoeff->modified = qfalse; + } + + // Reset currentEntity to world so that any previously referenced entities + // don't have influence on the rendering of these flares (i.e. RF_ renderer flags). + backEnd.currentEntity = &tr.worldEntity; + backEnd.or = backEnd.viewParms.world; + +// RB_AddDlightFlares(); + + // perform z buffer readback on each flare in this view + draw = qfalse; + prev = &r_activeFlares; + while ( ( f = *prev ) != NULL ) { + // throw out any flares that weren't added last frame + if ( f->addedFrame < backEnd.viewParms.frameCount - 1 ) { + *prev = f->next; + f->next = r_inactiveFlares; + r_inactiveFlares = f; + continue; + } + + // don't draw any here that aren't from this scene / portal + f->drawIntensity = 0; + if ( f->frameSceneNum == backEnd.viewParms.frameSceneNum + && f->inPortal == backEnd.viewParms.isPortal ) { + RB_TestFlare( f ); + if ( f->drawIntensity ) { + draw = qtrue; + } else { + // this flare has completely faded out, so remove it from the chain + *prev = f->next; + f->next = r_inactiveFlares; + r_inactiveFlares = f; + continue; + } + } + + prev = &f->next; + } + + if ( !draw ) { + return; // none visible + } + + if ( backEnd.viewParms.isPortal ) { + qglDisable (GL_CLIP_PLANE0); + } + + qglPushMatrix(); + qglLoadIdentity(); + qglMatrixMode( GL_PROJECTION ); + qglPushMatrix(); + qglLoadIdentity(); + qglOrtho( backEnd.viewParms.viewportX, backEnd.viewParms.viewportX + backEnd.viewParms.viewportWidth, + backEnd.viewParms.viewportY, backEnd.viewParms.viewportY + backEnd.viewParms.viewportHeight, + -99999, 99999 ); + + for ( f = r_activeFlares ; f ; f = f->next ) { + if ( f->frameSceneNum == backEnd.viewParms.frameSceneNum + && f->inPortal == backEnd.viewParms.isPortal + && f->drawIntensity ) { + RB_RenderFlare( f ); + } + } + + qglPopMatrix(); + qglMatrixMode( GL_MODELVIEW ); + qglPopMatrix(); +} + |