probabilistic sample dispersion for minimap -samples

git-svn-id: svn://svn.icculus.org/netradiant/trunk@339 61c419a2-8eb2-4b30-bcec-8cead039b335

diff --git a/tools/quake3/q3map2/main.c b/tools/quake3/q3map2/main.c
index 4a646ffa9315e9d5054c6d173e2718dc42a886f0..09e73bd3c8c9e2accc04076e8618a52b46734b90 100644 (file)
--- a/tools/quake3/q3map2/main.c
+++ b/tools/quake3/q3map2/main.c
@@ -177,6 +177,16 @@ static float MiniMapSample(float x, float y)
        return samp;
 }
 
+void RandomVector2f(float v[2])
+{
+       do
+       {
+               v[0] = 2 * Random() - 1;
+               v[1] = 2 * Random() - 1;
+       }
+       while(v[0] * v[0] + v[1] * v[1] > 1);
+}
+
 static void MiniMapRandomlySupersampled(int y)
 {
        int x, i;
@@ -184,6 +194,7 @@ static void MiniMapRandomlySupersampled(int y)
        float ymin = minimap.mins[1] + minimap.size[1] * (y / (float) minimap.height);
        float dx   =                   minimap.size[0]      / (float) minimap.width;
        float dy   =                   minimap.size[1]      / (float) minimap.height;
+       float uv[2];
 
        for(x = 0; x < minimap.width; ++x)
        {
@@ -192,9 +203,10 @@ static void MiniMapRandomlySupersampled(int y)
 
                for(i = 0; i < minimap.samples; ++i)
                {
+                       RandomVector2f(uv);
                        float thisval = MiniMapSample(
-                               xmin + (2 * Random() - 0.5) * dx, /* exaggerated random pattern for better results */
-                               ymin + (2 * Random() - 0.5) * dy  /* exaggerated random pattern for better results */
+                               xmin + (uv[0] + 0.5) * dx, /* exaggerated random pattern for better results */
+                               ymin + (uv[1] + 0.5) * dy  /* exaggerated random pattern for better results */
                        );
                        val += thisval;
                }
@@ -385,6 +397,107 @@ void MiniMapSetupBrushes( void )
        Sys_FPrintf( SYS_VRB, "%9d solid brushes\n", numOpaqueBrushes );
 }
 
+qboolean MiniMapEvaluateSampleOffsets(int *bestj, int *bestk, float *bestval)
+{
+       float val, dx, dy;
+       int j, k;
+
+       *bestj = *bestk = -1;
+       *bestval = 3; /* max possible val is 2 */
+
+       for(j = 0; j < minimap.samples; ++j)
+               for(k = j + 1; k < minimap.samples; ++k)
+               {
+                       dx = minimap.sample_offsets[2*j+0] - minimap.sample_offsets[2*k+0];
+                       dy = minimap.sample_offsets[2*j+1] - minimap.sample_offsets[2*k+1];
+                       if(dx > +0.5) dx -= 1;
+                       if(dx < -0.5) dx += 1;
+                       if(dy > +0.5) dy -= 1;
+                       if(dy < -0.5) dy += 1;
+                       val = dx * dx + dy * dy;
+                       if(val < *bestval)
+                       {
+                               *bestj = j;
+                               *bestk = k;
+                               *bestval = val;
+                       }
+               }
+       
+       return *bestval < 3;
+}
+
+void MiniMapMakeSampleOffsets()
+{
+       int i, j, k, jj, kk;
+       float val, valj, valk, dx, dy, sx, sy, rx, ry;
+
+       Sys_Printf( "Generating good sample offsets (this may take a while)...\n" );
+
+       /* start with entirely random samples */
+       for(i = 0; i < minimap.samples; ++i)
+       {
+               minimap.sample_offsets[2*i+0] = Random();
+               minimap.sample_offsets[2*i+1] = Random();
+       }
+
+       for(i = 0; i < 1000; ++i)
+       {
+               if(MiniMapEvaluateSampleOffsets(&j, &k, &val))
+               {
+                       sx = minimap.sample_offsets[2*j+0];
+                       sy = minimap.sample_offsets[2*j+1];
+                       minimap.sample_offsets[2*j+0] = rx = Random();
+                       minimap.sample_offsets[2*j+1] = ry = Random();
+                       if(!MiniMapEvaluateSampleOffsets(&jj, &kk, &valj))
+                               valj = -1;
+                       minimap.sample_offsets[2*j+0] = sx;
+                       minimap.sample_offsets[2*j+1] = sy;
+
+                       sx = minimap.sample_offsets[2*k+0];
+                       sy = minimap.sample_offsets[2*k+1];
+                       minimap.sample_offsets[2*k+0] = rx;
+                       minimap.sample_offsets[2*k+1] = ry;
+                       if(!MiniMapEvaluateSampleOffsets(&jj, &kk, &valk))
+                               valk = -1;
+                       minimap.sample_offsets[2*k+0] = sx;
+                       minimap.sample_offsets[2*k+1] = sy;
+
+                       if(valj > valk)
+                       {
+                               if(valj > val)
+                               {
+                                       /* valj is the greatest */
+                                       minimap.sample_offsets[2*j+0] = rx;
+                                       minimap.sample_offsets[2*j+1] = ry;
+                                       i = -1;
+                                       Sys_Printf("%f\n", val);
+                               }
+                               else
+                               {
+                                       /* valj is the greater and it is useless - forget it */
+                               }
+                       }
+                       else
+                       {
+                               if(valk > val)
+                               {
+                                       /* valk is the greatest */
+                                       minimap.sample_offsets[2*k+0] = rx;
+                                       minimap.sample_offsets[2*k+1] = ry;
+                                       i = -1;
+                                       Sys_Printf("%f\n", val);
+                               }
+                               else
+                               {
+                                       /* valk is the greater and it is useless - forget it */
+                               }
+                       }
+               }
+               else
+                       break;
+       }
+}
+
 int MiniMapBSPMain( int argc, char **argv )
 {
        char minimapFilename[1024];
@@ -446,9 +559,7 @@ int MiniMapBSPMain( int argc, char **argv )
                        if(minimap.sample_offsets)
                                free(minimap.sample_offsets);
                        minimap.sample_offsets = malloc(2 * sizeof(*minimap.sample_offsets) * minimap.samples);
-                       /* TODO use a better pattern */
-                       for(x = 0; x < 2 * minimap.samples; ++x)
-                               minimap.sample_offsets[x] = Random();
+                       MiniMapMakeSampleOffsets();
                }
                else if( !strcmp( argv[ i ],  "-random" ) )
                {