support for top to bottom TGA, thanks Elric.

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@2216 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/image.c b/image.c
index f36e975d75627102d3369bd847a72316a384a330..d388637b14d2edb818a16de76525dada6c6f6ee3 100644 (file)
--- a/image.c
+++ b/image.c
@@ -207,7 +207,7 @@ LoadTGA
 */
 qbyte *LoadTGA (qbyte *f, int matchwidth, int matchheight)
 {
-       int columns, rows, row, column;
+       int columns, rows, row, column, row_inc;
        qbyte *pixbuf, *image_rgba, *fin, *enddata;
 
        if (loadsize < 18+3)
@@ -258,12 +258,23 @@ qbyte *LoadTGA (qbyte *f, int matchwidth, int matchheight)
        if (targa_header.id_length != 0)
                fin += targa_header.id_length;  // skip TARGA image comment
 
+       // If bit 5 of attributes isn't set, the image has been stored from bottom to top
+       if ((targa_header.attributes & 0x20) == 0)
+       {
+               pixbuf = image_rgba + (rows - 1)*columns*4;
+               row_inc = -columns*4*2;
+       }
+       else
+       {
+               pixbuf = image_rgba;
+               row_inc = 0;
+       }
+
        if (targa_header.image_type == 2)
        {
                // Uncompressed, RGB images
-               for(row = rows - 1;row >= 0;row--)
+               for(row = 0;row < rows;row++)
                {
-                       pixbuf = image_rgba + row*columns*4;
                        for(column = 0;column < columns;column++)
                        {
                                switch (targa_header.pixel_size)
@@ -288,15 +299,15 @@ qbyte *LoadTGA (qbyte *f, int matchwidth, int matchheight)
                                        break;
                                }
                        }
+                       pixbuf += row_inc;
                }
        }
        else if (targa_header.image_type==10)
        {
                // Runlength encoded RGB images
                unsigned char red = 0, green = 0, blue = 0, alphabyte = 0, packetHeader, packetSize, j;
-               for(row = rows - 1;row >= 0;row--)
+               for(row = 0;row < rows;row++)
                {
-                       pixbuf = image_rgba + row * columns * 4;
                        for(column = 0;column < columns;)
                        {
                                if (fin >= enddata)
@@ -337,11 +348,11 @@ qbyte *LoadTGA (qbyte *f, int matchwidth, int matchheight)
                                                {
                                                        // run spans across rows
                                                        column = 0;
-                                                       if (row > 0)
-                                                               row--;
+                                                       if (row < rows - 1)
+                                                               row++;
                                                        else
                                                                goto breakOut;
-                                                       pixbuf = image_rgba + row * columns * 4;
+                                                       pixbuf += row_inc;
                                                }
                                        }
                                }
@@ -376,15 +387,16 @@ qbyte *LoadTGA (qbyte *f, int matchwidth, int matchheight)
                                                {
                                                        // pixel packet run spans across rows
                                                        column = 0;
-                                                       if (row > 0)
-                                                               row--;
+                                                       if (row < rows - 1)
+                                                               row++;
                                                        else
                                                                goto breakOut;
-                                                       pixbuf = image_rgba + row * columns * 4;
+                                                       pixbuf += row_inc;
                                                }
                                        }
                                }
                        }
+                       pixbuf += row_inc;
                        breakOut:;
                }
        }