save 24bit tga if alpha channel is entirely 255

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@7546 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/image.c b/image.c
index be151e7892bbc8d4e018e0753bcca08ecf935a11..bc58a7247e43c155f1b73b3e7485f076751a54a0 100644 (file)
--- a/image.c
+++ b/image.c
@@ -961,24 +961,54 @@ void Image_WriteTGARGBA (const char *filename, int width, int height, const unsi
        buffer[13] = (width >> 8) & 0xFF;
        buffer[14] = (height >> 0) & 0xFF;
        buffer[15] = (height >> 8) & 0xFF;
-       buffer[16] = 32;        // pixel size
-       buffer[17] = 8; // 8 bits of alpha
 
-       // swap rgba to bgra and flip upside down
-       out = buffer + 18;
-       for (y = height - 1;y >= 0;y--)
+       for (y = 3;y < width*height*4;y += 4)
+               if (data[y] < 255)
+                       break;
+
+       if (y < width*height*4)
        {
-               in = data + y * width * 4;
-               end = in + width * 4;
-               for (;in < end;in += 4)
+               // save the alpha channel
+               buffer[16] = 32;        // pixel size
+               buffer[17] = 8; // 8 bits of alpha
+
+               // swap rgba to bgra and flip upside down
+               out = buffer + 18;
+               for (y = height - 1;y >= 0;y--)
                {
-                       *out++ = in[2];
-                       *out++ = in[1];
-                       *out++ = in[0];
-                       *out++ = in[3];
+                       in = data + y * width * 4;
+                       end = in + width * 4;
+                       for (;in < end;in += 4)
+                       {
+                               *out++ = in[2];
+                               *out++ = in[1];
+                               *out++ = in[0];
+                               *out++ = in[3];
+                       }
+               }
+               FS_WriteFile (filename, buffer, width*height*4 + 18 );
+       }
+       else
+       {
+               // save only the color channels
+               buffer[16] = 24;        // pixel size
+               buffer[17] = 0; // 8 bits of alpha
+
+               // swap rgba to bgr and flip upside down
+               out = buffer + 18;
+               for (y = height - 1;y >= 0;y--)
+               {
+                       in = data + y * width * 4;
+                       end = in + width * 4;
+                       for (;in < end;in += 4)
+                       {
+                               *out++ = in[2];
+                               *out++ = in[1];
+                               *out++ = in[0];
+                       }
                }
+               FS_WriteFile (filename, buffer, width*height*3 + 18 );
        }
-       FS_WriteFile (filename, buffer, width*height*4 + 18 );
 
        Mem_Free(buffer);
 }