reworked Image_HeightmapToNormalmap to use a somewhat blurrier but more consistent...

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@6827 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/image.c b/image.c
index fa2252d628eca0caed6c9ad00514fb799ecbfe59..27eaa5d70e8880e51e69a091374452064238732b 100644 (file)
--- a/image.c
+++ b/image.c
@@ -1495,64 +1495,42 @@ void Image_MipReduce(const unsigned char *in, unsigned char *out, int *width, in
 
 void Image_HeightmapToNormalmap(const unsigned char *inpixels, unsigned char *outpixels, int width, int height, int clamp, float bumpscale)
 {
-       int x, y;
-       const unsigned char *p0, *p1, *p2;
+       int x, y, x1, x2, y1, y2;
+       const unsigned char *b, *row[3];
+       int p[5];
        unsigned char *out;
        float iwidth, iheight, ibumpscale, n[3];
        iwidth = 1.0f / width;
        iheight = 1.0f / height;
-       ibumpscale = (255.0f * 3.0f) / bumpscale;
+       ibumpscale = (255.0f * 6.0f) / bumpscale;
        out = outpixels;
-       for (y = 0;y < height;y++)
+       for (y = 0, y1 = height-1;y < height;y1 = y, y++)
        {
-               for (x = 0;x < width;x++)
+               y2 = y + 1;if (y2 >= height) y2 = 0;
+               row[0] = inpixels + (y1 * width) * 4;
+               row[1] = inpixels + (y  * width) * 4;
+               row[2] = inpixels + (y2 * width) * 4;
+               for (x = 0, x1 = width-1;x < width;x1 = x, x++)
                {
-                       p0 = inpixels + (y * width + x) * 4;
-                       if (x == width - 1)
-                       {
-                               if (clamp)
-                                       p1 = inpixels + (y * width + x) * 4;
-                               else
-                                       p1 = inpixels + (y * width) * 4;
-                       }
-                       else
-                               p1 = inpixels + (y * width + x + 1) * 4;
-                       if (y == height - 1)
-                       {
-                               if (clamp)
-                                       p2 = inpixels + (y * width + x) * 4;
-                               else
-                                       p2 = inpixels + x * 4;
-                       }
-                       else
-                               p2 = inpixels + ((y + 1) * width + x) * 4;
-                       /*
-                       dv[0][0] = iwidth;
-                       dv[0][1] = 0;
-                       dv[0][2] = ((p0[0] + p0[1] + p0[2]) * ibumpscale) - ((p1[0] + p1[1] + p1[2]) * ibumpscale);
-                       dv[1][0] = 0;
-                       dv[1][1] = iheight;
-                       dv[1][2] = ((p2[0] + p2[1] + p2[2]) * ibumpscale) - ((p0[0] + p0[1] + p0[2]) * ibumpscale);
-                       n[0] = dv[0][1]*dv[1][2]-dv[0][2]*dv[1][1];
-                       n[1] = dv[0][2]*dv[1][0]-dv[0][0]*dv[1][2];
-                       n[2] = dv[0][0]*dv[1][1]-dv[0][1]*dv[1][0];
-                       */
-                       n[0] = ((p0[0] + p0[1] + p0[2]) - (p1[0] + p1[1] + p1[2]));
-                       n[1] = ((p2[0] + p2[1] + p2[2]) - (p0[0] + p0[1] + p0[2]));
-                       n[2] = ibumpscale;
-                       VectorNormalize(n);
-                       /*
-                       // this should work for the bottom right triangle if anyone wants
-                       // code for that for some reason
-                       n[0] = ((p3[0] + p3[1] + p3[2]) - (p1[0] + p1[1] + p1[2]));
-                       n[1] = ((p2[0] + p2[1] + p2[2]) - (p3[0] + p3[1] + p3[2]));
+                       x2 = x + 1;if (x2 >= width) x2 = 0;
+                       // left, right
+                       b = row[1] + x1 * 4;p[0] = (b[0] + b[1] + b[2]);
+                       b = row[1] + x2 * 4;p[1] = (b[0] + b[1] + b[2]);
+                       // above, below
+                       b = row[0] + x  * 4;p[2] = (b[0] + b[1] + b[2]);
+                       b = row[2] + x  * 4;p[3] = (b[0] + b[1] + b[2]);
+                       // center
+                       b = row[1] + x  * 4;p[4] = (b[0] + b[1] + b[2]);
+                       // calculate a normal from the slopes
+                       n[0] = p[0] - p[1];
+                       n[1] = p[3] - p[2];
                        n[2] = ibumpscale;
                        VectorNormalize(n);
-                       */
+                       // turn it into a dot3 rgb vector texture
                        out[0] = (int)(128.0f + n[0] * 127.0f);
                        out[1] = (int)(128.0f + n[1] * 127.0f);
                        out[2] = (int)(128.0f + n[2] * 127.0f);
-                       out[3] = (p0[0] + p0[1] + p0[2]) / 3;
+                       out[3] = (p[4]) / 3;
                        out += 4;
                }
        }