2 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
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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.
47 // -----------------------------------------------------------------------------
48 // Return light intensity at an instance of a vertex on a side in a segment.
49 fix get_light_intensity(segment *segp, int sidenum, int vert)
51 Assert(sidenum <= MAX_SIDES_PER_SEGMENT);
54 return segp->sides[sidenum].uvls[vert].l;
57 // -----------------------------------------------------------------------------
58 // Set light intensity at a vertex, saturating in .5 to 15.5
59 void set_light_intensity(segment *segp, int sidenum, int vert, fix intensity)
61 Assert(sidenum <= MAX_SIDES_PER_SEGMENT);
64 if (intensity < MIN_LIGHTING_VALUE)
65 intensity = MIN_LIGHTING_VALUE;
67 if (intensity > MAX_LIGHTING_VALUE)
68 intensity = MAX_LIGHTING_VALUE;
70 segp->sides[sidenum].uvls[vert].l = intensity;
72 Update_flags |= UF_WORLD_CHANGED;
76 // -----------------------------------------------------------------------------
77 // Add light intensity to a vertex, saturating in .5 to 15.5
78 void add_light_intensity(segment *segp, int sidenum, int vert, fix intensity)
82 set_light_intensity(segp, sidenum, vert, segp->sides[sidenum].uvls[vert].l + intensity);
86 // -----------------------------------------------------------------------------
87 // Recursively apply light to segments.
88 // If current side is a wall, apply light there.
89 // If not a wall, apply light to child through that wall.
91 // It is possible to enter a segment twice by taking different paths. It is easy
92 // to prevent this by maintaining a list of visited segments, but it is important
93 // to reach segments with the greatest light intensity. This can be done by doing
94 // a breadth-first-search, or by storing the applied intensity with a visited segment,
95 // and if the current intensity is brighter, then apply the difference between it and
96 // the previous intensity.
97 // Note that it is also possible to visit the original light-casting segment, for example
98 // going from segment 0 to 2, then from 2 to 0. This is peculiar and probably not
99 // desired, but not entirely invalid. 2 reflects some light back to 0.
100 void apply_light_intensity(segment *segp, int sidenum, fix intensity, int depth)
107 wid_result = WALL_IS_DOORWAY(segp, sidenum);
108 if ((wid_result != WID_FLY_FLAG) && (wid_result != WID_NO_WALL)) {
110 for (v=0; v<4; v++) // add light to this wall
111 add_light_intensity(segp, sidenum, v, intensity);
112 return; // we return because there is a wall here, and light does not shine through walls
115 // No wall here, so apply light recursively
118 for (s=0; s<MAX_SIDES_PER_SEGMENT; s++)
119 apply_light_intensity(&Segments[segp->children[sidenum]], s, intensity/3, depth+1);
124 // -----------------------------------------------------------------------------
125 // Top level recursive function for applying light.
126 // Calls apply_light_intensity.
127 // Uses light value on segp:sidenum (tmap_num2 defines light value) and applies
128 // the associated intensity to segp. It calls apply_light_intensity to apply intensity/3
129 // to all neighbors. apply_light_intensity recursively calls itself to apply light to
130 // subsequent neighbors (and forming loops, see above).
131 void propagate_light_intensity(segment *segp, int sidenum)
138 texmap = segp->sides[sidenum].tmap_num;
139 intensity += TmapInfo[texmap].lighting;
140 texmap = (segp->sides[sidenum].tmap_num2) & 0x3fff;
141 intensity += TmapInfo[texmap].lighting;
145 add_light_intensity(segp, sidenum, v, intensity);
147 // Now, for all sides which are not the same as sidenum (the side casting the light),
148 // add a light value to them (if they have no children, ie, they have a wall there).
149 for (s=0; s<MAX_SIDES_PER_SEGMENT; s++)
151 apply_light_intensity(segp, s, intensity/2, 1);
157 // -----------------------------------------------------------------------------
158 // Highest level function, bound to a key. Apply ambient light to all segments based
159 // on user-defined light sources.
160 int LightAmbientLighting()
164 for (seg=0; seg<=Highest_segment_index; seg++)
165 for (side=0;side<MAX_SIDES_PER_SEGMENT;side++)
166 propagate_light_intensity(&Segments[seg], side);
171 // -----------------------------------------------------------------------------
172 int LightSelectNextVertex(void)
178 Update_flags |= UF_WORLD_CHANGED;
183 // -----------------------------------------------------------------------------
184 int LightSelectNextEdge(void)
190 Update_flags |= UF_WORLD_CHANGED;
195 // -----------------------------------------------------------------------------
196 // Copy intensity from current vertex to all other vertices on side.
197 int LightCopyIntensity(void)
201 intensity = get_light_intensity(Cursegp, Curside, Curvert);
205 set_light_intensity(Cursegp, Curside, v, intensity);
210 // -----------------------------------------------------------------------------
211 // Copy intensity from current vertex to all other vertices on side.
212 int LightCopyIntensitySegment(void)
216 intensity = get_light_intensity(Cursegp, Curside, Curvert);
218 for (s=0; s<MAX_SIDES_PER_SEGMENT; s++)
220 if ((s != Curside) || (v != Curvert))
221 set_light_intensity(Cursegp, s, v, intensity);
226 // -----------------------------------------------------------------------------
227 int LightDecreaseLightVertex(void)
229 set_light_intensity(Cursegp, Curside, Curvert, get_light_intensity(Cursegp, Curside, Curvert)-F1_0/NUM_LIGHTING_LEVELS);
234 // -----------------------------------------------------------------------------
235 int LightIncreaseLightVertex(void)
237 set_light_intensity(Cursegp, Curside, Curvert, get_light_intensity(Cursegp, Curside, Curvert)+F1_0/NUM_LIGHTING_LEVELS);
242 // -----------------------------------------------------------------------------
243 int LightDecreaseLightSide(void)
248 set_light_intensity(Cursegp, Curside, v, get_light_intensity(Cursegp, Curside, v)-F1_0/NUM_LIGHTING_LEVELS);
253 // -----------------------------------------------------------------------------
254 int LightIncreaseLightSide(void)
259 set_light_intensity(Cursegp, Curside, v, get_light_intensity(Cursegp, Curside, v)+F1_0/NUM_LIGHTING_LEVELS);
264 // -----------------------------------------------------------------------------
265 int LightDecreaseLightSegment(void)
269 for (s=0; s<MAX_SIDES_PER_SEGMENT; s++)
271 set_light_intensity(Cursegp, s, v, get_light_intensity(Cursegp, s, v)-F1_0/NUM_LIGHTING_LEVELS);
276 // -----------------------------------------------------------------------------
277 int LightIncreaseLightSegment(void)
281 for (s=0; s<MAX_SIDES_PER_SEGMENT; s++)
283 set_light_intensity(Cursegp, s, v, get_light_intensity(Cursegp, s, v)+F1_0/NUM_LIGHTING_LEVELS);
288 // -----------------------------------------------------------------------------
289 int LightSetDefault(void)
294 set_light_intensity(Cursegp, Curside, v, DEFAULT_LIGHTING);
300 // -----------------------------------------------------------------------------
301 int LightSetMaximum(void)
306 set_light_intensity(Cursegp, Curside, v, (NUM_LIGHTING_LEVELS-1)*F1_0/NUM_LIGHTING_LEVELS);
312 // -----------------------------------------------------------------------------
313 int LightSetDefaultAll(void)
316 assign_default_lighting_all();
318 Update_flags |= UF_WORLD_CHANGED;