2 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
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8 FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
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10 AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
11 COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED.
16 * Editor lighting functions.
38 // -----------------------------------------------------------------------------
39 // Return light intensity at an instance of a vertex on a side in a segment.
40 fix get_light_intensity(segment *segp, int sidenum, int vert)
42 Assert(sidenum <= MAX_SIDES_PER_SEGMENT);
45 return segp->sides[sidenum].uvls[vert].l;
48 // -----------------------------------------------------------------------------
49 // Set light intensity at a vertex, saturating in .5 to 15.5
50 void set_light_intensity(segment *segp, int sidenum, int vert, fix intensity)
52 Assert(sidenum <= MAX_SIDES_PER_SEGMENT);
55 if (intensity < MIN_LIGHTING_VALUE)
56 intensity = MIN_LIGHTING_VALUE;
58 if (intensity > MAX_LIGHTING_VALUE)
59 intensity = MAX_LIGHTING_VALUE;
61 segp->sides[sidenum].uvls[vert].l = intensity;
63 Update_flags |= UF_WORLD_CHANGED;
67 // -----------------------------------------------------------------------------
68 // Add light intensity to a vertex, saturating in .5 to 15.5
69 void add_light_intensity(segment *segp, int sidenum, int vert, fix intensity)
73 set_light_intensity(segp, sidenum, vert, segp->sides[sidenum].uvls[vert].l + intensity);
77 // -----------------------------------------------------------------------------
78 // Recursively apply light to segments.
79 // If current side is a wall, apply light there.
80 // If not a wall, apply light to child through that wall.
82 // It is possible to enter a segment twice by taking different paths. It is easy
83 // to prevent this by maintaining a list of visited segments, but it is important
84 // to reach segments with the greatest light intensity. This can be done by doing
85 // a breadth-first-search, or by storing the applied intensity with a visited segment,
86 // and if the current intensity is brighter, then apply the difference between it and
87 // the previous intensity.
88 // Note that it is also possible to visit the original light-casting segment, for example
89 // going from segment 0 to 2, then from 2 to 0. This is peculiar and probably not
90 // desired, but not entirely invalid. 2 reflects some light back to 0.
91 void apply_light_intensity(segment *segp, int sidenum, fix intensity, int depth)
98 wid_result = WALL_IS_DOORWAY(segp, sidenum);
99 if ((wid_result != WID_FLY_FLAG) && (wid_result != WID_NO_WALL)) {
101 for (v=0; v<4; v++) // add light to this wall
102 add_light_intensity(segp, sidenum, v, intensity);
103 return; // we return because there is a wall here, and light does not shine through walls
106 // No wall here, so apply light recursively
109 for (s=0; s<MAX_SIDES_PER_SEGMENT; s++)
110 apply_light_intensity(&Segments[segp->children[sidenum]], s, intensity/3, depth+1);
115 // -----------------------------------------------------------------------------
116 // Top level recursive function for applying light.
117 // Calls apply_light_intensity.
118 // Uses light value on segp:sidenum (tmap_num2 defines light value) and applies
119 // the associated intensity to segp. It calls apply_light_intensity to apply intensity/3
120 // to all neighbors. apply_light_intensity recursively calls itself to apply light to
121 // subsequent neighbors (and forming loops, see above).
122 void propagate_light_intensity(segment *segp, int sidenum)
129 texmap = segp->sides[sidenum].tmap_num;
130 intensity += TmapInfo[texmap].lighting;
131 texmap = (segp->sides[sidenum].tmap_num2) & 0x3fff;
132 intensity += TmapInfo[texmap].lighting;
136 add_light_intensity(segp, sidenum, v, intensity);
138 // Now, for all sides which are not the same as sidenum (the side casting the light),
139 // add a light value to them (if they have no children, ie, they have a wall there).
140 for (s=0; s<MAX_SIDES_PER_SEGMENT; s++)
142 apply_light_intensity(segp, s, intensity/2, 1);
148 // -----------------------------------------------------------------------------
149 // Highest level function, bound to a key. Apply ambient light to all segments based
150 // on user-defined light sources.
151 int LightAmbientLighting()
155 for (seg=0; seg<=Highest_segment_index; seg++)
156 for (side=0;side<MAX_SIDES_PER_SEGMENT;side++)
157 propagate_light_intensity(&Segments[seg], side);
162 // -----------------------------------------------------------------------------
163 int LightSelectNextVertex(void)
169 Update_flags |= UF_WORLD_CHANGED;
174 // -----------------------------------------------------------------------------
175 int LightSelectNextEdge(void)
181 Update_flags |= UF_WORLD_CHANGED;
186 // -----------------------------------------------------------------------------
187 // Copy intensity from current vertex to all other vertices on side.
188 int LightCopyIntensity(void)
192 intensity = get_light_intensity(Cursegp, Curside, Curvert);
196 set_light_intensity(Cursegp, Curside, v, intensity);
201 // -----------------------------------------------------------------------------
202 // Copy intensity from current vertex to all other vertices on side.
203 int LightCopyIntensitySegment(void)
207 intensity = get_light_intensity(Cursegp, Curside, Curvert);
209 for (s=0; s<MAX_SIDES_PER_SEGMENT; s++)
211 if ((s != Curside) || (v != Curvert))
212 set_light_intensity(Cursegp, s, v, intensity);
217 // -----------------------------------------------------------------------------
218 int LightDecreaseLightVertex(void)
220 set_light_intensity(Cursegp, Curside, Curvert, get_light_intensity(Cursegp, Curside, Curvert)-F1_0/NUM_LIGHTING_LEVELS);
225 // -----------------------------------------------------------------------------
226 int LightIncreaseLightVertex(void)
228 set_light_intensity(Cursegp, Curside, Curvert, get_light_intensity(Cursegp, Curside, Curvert)+F1_0/NUM_LIGHTING_LEVELS);
233 // -----------------------------------------------------------------------------
234 int LightDecreaseLightSide(void)
239 set_light_intensity(Cursegp, Curside, v, get_light_intensity(Cursegp, Curside, v)-F1_0/NUM_LIGHTING_LEVELS);
244 // -----------------------------------------------------------------------------
245 int LightIncreaseLightSide(void)
250 set_light_intensity(Cursegp, Curside, v, get_light_intensity(Cursegp, Curside, v)+F1_0/NUM_LIGHTING_LEVELS);
255 // -----------------------------------------------------------------------------
256 int LightDecreaseLightSegment(void)
260 for (s=0; s<MAX_SIDES_PER_SEGMENT; s++)
262 set_light_intensity(Cursegp, s, v, get_light_intensity(Cursegp, s, v)-F1_0/NUM_LIGHTING_LEVELS);
267 // -----------------------------------------------------------------------------
268 int LightIncreaseLightSegment(void)
272 for (s=0; s<MAX_SIDES_PER_SEGMENT; s++)
274 set_light_intensity(Cursegp, s, v, get_light_intensity(Cursegp, s, v)+F1_0/NUM_LIGHTING_LEVELS);
279 // -----------------------------------------------------------------------------
280 int LightSetDefault(void)
285 set_light_intensity(Cursegp, Curside, v, DEFAULT_LIGHTING);
291 // -----------------------------------------------------------------------------
292 int LightSetMaximum(void)
297 set_light_intensity(Cursegp, Curside, v, (NUM_LIGHTING_LEVELS-1)*F1_0/NUM_LIGHTING_LEVELS);
303 // -----------------------------------------------------------------------------
304 int LightSetDefaultAll(void)
307 assign_default_lighting_all();
309 Update_flags |= UF_WORLD_CHANGED;