ref: e11e7cb42d1762154194fc58eb200dd0fe1c47bd
parent: 99f04725a106190feb2f923ebbc555bfefc277ef
author: Fabien Sanglard <[email protected]>
date: Wed Dec 12 23:47:24 EST 2012
Added comment for Visible Surface Determination
--- a/Engine/src/a.c
+++ b/Engine/src/a.c
@@ -201,7 +201,7 @@
if (i3 == 0)
{if (!RENDER_DRAW_TOP_AND_BOTTOM_COLUMN)
- return;
+ return 0;
i1 += i4;
//FCS
@@ -226,7 +226,7 @@
unsigned char *dest = (unsigned char *)i6;
if (!RENDER_DRAW_WALL_BORDERS)
- return;
+ return vplce;
i3++;
while (i3)
--- a/Engine/src/build.h
+++ b/Engine/src/build.h
@@ -311,14 +311,16 @@
//FCS: In order to see how the engine renders different part of the screen you can set the following macros
//VISUALIZE RENDERER
-#define RENDER_DRAW_WALL_BORDERS 0
-#define RENDER_DRAW_WALL_INSIDE 0
-#define RENDER_DRAW_CEILING_AND_FLOOR 0
+#define RENDER_DRAW_WALL_BORDERS 1
+#define RENDER_DRAW_WALL_INSIDE 1
+#define RENDER_DRAW_CEILING_AND_FLOOR 1
#define RENDER_DRAW_TOP_AND_BOTTOM_COLUMN 1
-#define RENDER_SLOPPED_CEILING_AND_FLOOR 0
+#define RENDER_SLOPPED_CEILING_AND_FLOOR 1
-#if RENDER_DRAW_WALL_BORDERS || RENDER_DRAW_WALL_INSIDE || RENDER_DRAW_CEILING_AND_FLOOR || RENDER_DRAW_TOP_AND_BOTTOM_COLUMN || RENDER_SLOPPED_CEILING_AND_FLOOR
-#define CLEAR_FRAMEBUFFER 1
+#if RENDER_DRAW_WALL_BORDERS && RENDER_DRAW_WALL_INSIDE && RENDER_DRAW_CEILING_AND_FLOOR && RENDER_DRAW_TOP_AND_BOTTOM_COLUMN && RENDER_SLOPPED_CEILING_AND_FLOOR
+ #define CLEAR_FRAMEBUFFER 0
+#else
+ #define CLEAR_FRAMEBUFFER 1
#endif
//END VISUALIZE RENDERER
--- a/Engine/src/engine.c
+++ b/Engine/src/engine.c
@@ -228,7 +228,10 @@
long globalx1, globaly1, globalx2, globaly2, globalx3, globaly3, globalzx;
long globalx, globaly, globalz;
+//Those two variables are using during portal flooding:
+// sectorBorder is the stack and sectorbordercnt is the stack counter.
static short sectorborder[256], sectorbordercnt;
+
static char tablesloaded = 0;
long pageoffset, ydim16, qsetmode = 0;
long startposx, startposy, startposz;
@@ -339,7 +342,10 @@
return((D<<24)|((D<<8)&0x00FF0000)|((D>>8)&0x0000FF00)|(D>>24));
}
-
+/*
+ FCS: Scan through sectors using portals (a portal is wall with a nextwall attribute != -1).
+ Flood is prevented if a portal does not face the POV.
+ */
static void scansector (short sectnum)
{walltype *wal, *wal2;
@@ -357,6 +363,7 @@
{sectnum = sectorborder[--sectorbordercnt];
+ //Add every script in the current sector as potentially visible.
for(z=headspritesect[sectnum];z>=0;z=nextspritesect[z])
{spr = &sprite[z];
@@ -373,6 +380,7 @@
}
}
+ //Mark the current sector as "visited"
gotsector[sectnum>>3] |= pow2char[sectnum&7];
bunchfrst = numbunches;
@@ -386,35 +394,53 @@
nextsectnum = wal->nextsector;
wal2 = &wall[wal->point2];
+
+ // In camera space the center is the player.
+ // Make the camrea the center of the world: Wall coordinates
x1 = wal->x-globalposx; y1 = wal->y-globalposy;
x2 = wal2->x-globalposx; y2 = wal2->y-globalposy;
+ // If this is a portal...
if ((nextsectnum >= 0) && ((wal->cstat&32) == 0))
+ //If this portal has not been visited.
if ((gotsector[nextsectnum>>3]&pow2char[nextsectnum&7]) == 0)
{templong = x1*y2-x2*y1;
+
+ // Using cross product, determine if the portal is facing us or not.
+ // If it is: Add it to the stack and bump the stack counter.
if (((unsigned)templong+262144) < 524288)
if (mulscale5(templong,templong) <= (x2-x1)*(x2-x1)+(y2-y1)*(y2-y1))
sectorborder[sectorbordercnt++] = nextsectnum;
}
+ // Rotate the wall endpoint position according to the player orientation.
+ // This is a regular rotation matrix using [29.3] fixed point.
if ((z == startwall) || (wall[z-1].point2 != z))
{+ //If this is the first endpoint of the bunch, rotate
xp1 = dmulscale6(y1,cosglobalang,-x1,singlobalang);
yp1 = dmulscale6(x1,cosviewingrangeglobalang,y1,sinviewingrangeglobalang);
}
else
{+ //If this is NOT the first endpoint, Save the coordinate for next loop.
xp1 = xp2;
yp1 = yp2;
}
- xp2 = dmulscale6(y2,cosglobalang,-x2,singlobalang);
- yp2 = dmulscale6(x2,cosviewingrangeglobalang,y2,sinviewingrangeglobalang);
+ xp2 = dmulscale6(y2,cosglobalang,-x2,singlobalang);
+ yp2 = dmulscale6(x2,cosviewingrangeglobalang,y2,sinviewingrangeglobalang);
+
+
+
+ // No idea what this is.
if ((yp1 < 256) && (yp2 < 256)) goto skipitaddwall;
- /* If wall's NOT facing you */
+ /* If wall's NOT facing you */
if (dmulscale32(xp1,yp2,-xp2,yp1) >= 0) goto skipitaddwall;
+ // The wall is still not eligible for rendition: Let's do some more Frustrum culling !!
+
if (xp1 >= -yp1)
{if ((xp1 > yp1) || (yp1 == 0)) goto skipitaddwall;
@@ -463,15 +489,18 @@
p2[numscans-1] = scanfirst, scanfirst = numscans;
}
+ //FCS: TODO rename this p2[]. This name is an abomination
for(z=numscansbefore;z<numscans;z++)
if ((wall[thewall[z]].point2 != thewall[p2[z]]) || (xb2[z] >= xb1[p2[z]]))
bunchfirst[numbunches++] = p2[z], p2[z] = -1;
+ //For each bunch, cache the last wall of the bunch in bunchlast.
for(z=bunchfrst;z<numbunches;z++)
{for(zz=bunchfirst[z];p2[zz]>=0;zz=p2[zz]);
bunchlast[z] = zz;
}
+
} while (sectorbordercnt > 0);
}
@@ -2395,6 +2424,7 @@
if (j == 0) tempbuf[closest] = 1, closest = i, i = 0;
}
+ //Draw every solid walls in the bunch "closest"
drawalls(closest);
if (automapping)
@@ -3917,11 +3947,17 @@
i = sector[sectnum].wallnum;
do
{- y1 = wal->y-y; y2 = wall[wal->point2].y-y;
+ y1 = wal->y-y;
+ y2 = wall[wal->point2].y-y;
if ((y1^y2) < 0)
{- x1 = wal->x-x; x2 = wall[wal->point2].x-x;
- if ((x1^x2) >= 0) cnt ^= x1; else cnt ^= (x1*y2-x2*y1)^y2;
+ x1 = wal->x-x;
+ x2 = wall[wal->point2].x-x;
+
+ if ((x1^x2) >= 0)
+ cnt ^= x1;
+ else
+ cnt ^= (x1*y2-x2*y1)^y2;
}
wal++; i--;
} while (i);
@@ -6718,7 +6754,18 @@
return(bad);
}
-
+/*
+ FCS: x and y are the new position of the entity.
+ sectnum is an hint (the last known sector number of the entity)
+
+ Thanks to the "hint", the algorithm check:
+ 1. Is (x,y) inside sectors[sectnum].
+ 2. Flood in sectnum portal and check again if (x,y) is inside.
+ 3. Do a linear search on sectors[sectnum] from 0 to numSectors.
+
+ Note: Inside uses cross_product and return as soon as the point switch
+ from one side to the other.
+ */
void updatesector(long x, long y, short *sectnum)
{walltype *wal;
--- a/xcode/Duke3D.xcodeproj/project.pbxproj
+++ b/xcode/Duke3D.xcodeproj/project.pbxproj
@@ -99,7 +99,6 @@
2D7B621A1678885A00E35E54 /* pragmas.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; name = pragmas.c; path = ../../Engine/src/pragmas.c; sourceTree = "<group>"; }; 2D7B621B1678885A00E35E54 /* pragmas.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = pragmas.h; path = ../../Engine/src/pragmas.h; sourceTree = "<group>"; }; 2D7B621C1678885A00E35E54 /* sdl_driver.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; name = sdl_driver.c; path = ../../Engine/src/sdl_driver.c; sourceTree = "<group>"; };- 2D7B622E1678887600E35E54 /* win32_compat.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = win32_compat.h; path = ../../Engine/src/win32_compat.h; sourceTree = "<group>"; }; 2D7B622F1678895A00E35E54 /* macos_compat.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = macos_compat.h; path = ../../Engine/src/macos_compat.h; sourceTree = "<group>"; }; 2D7B623016788A9B00E35E54 /* SDL.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = SDL.framework; path = /Library/Frameworks/SDL.framework; sourceTree = "<absolute>"; }; 2D7B623216788AAB00E35E54 /* SDL_mixer.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = SDL_mixer.framework; path = /Library/Frameworks/SDL_mixer.framework; sourceTree = "<absolute>"; };@@ -227,7 +226,6 @@
2D7B621A1678885A00E35E54 /* pragmas.c */,
2D7B621B1678885A00E35E54 /* pragmas.h */,
2D7B621C1678885A00E35E54 /* sdl_driver.c */,
- 2D7B622E1678887600E35E54 /* win32_compat.h */,
2D7B622F1678895A00E35E54 /* macos_compat.h */,
2D7B630016791C0200E35E54 /* dummy_multi.c */,
);