detect alphapixels

diff --git a/s2tc.cpp b/s2tc.cpp
index 6982bfb..af6e5b0 100644 (file)
--- a/s2tc.cpp
+++ b/s2tc.cpp
@@ -589,23 +589,28 @@ int main(int argc, char **argv)
        }
 
        {
-               bool alphapixels = true; // FIXME
+               bool alphapixels = false;
+               for(int y = 0; y < image_height; ++y)
+                       for(int x = 0; x < image_width; ++x)
+                               if(picdata[(y*image_width+x)*4+3] != 255)
+                               {
+                                       alphapixels = true;
+                                       break;
+                               }
 
-               uint32_t picsize = LittleLong(((image_width+3)/4) * ((image_height+3)/4) * blocksize);
-               uint32_t one = LittleLong(1);
                uint32_t zero = LittleLong(0);
-               uint32_t dds_format_flags = LittleLong(alphapixels ? 0x05 : 0x04);
-               uint32_t dds_caps1 = LittleLong(0x401008);
-               uint32_t dds_format_size = LittleLong(32);
+               uint32_t dds_picsize = LittleLong(((image_width+3)/4) * ((image_height+3)/4) * blocksize);
                uint32_t dds_mipcount = LittleLong(mipcount);
+               uint32_t dds_width = LittleLong(image_width);
+               uint32_t dds_height = LittleLong(image_height);
 
                //0
                fwrite("DDS ", 4, 1, outfh);
                fwrite("\x7c\x00\x00\x00", 4, 1, outfh);
                fwrite("\x07\x10\x0a\x00", 4, 1, outfh);
-               fwrite(&image_height, 4, 1, outfh);
-               fwrite(&image_width, 4, 1, outfh);
-               fwrite(&picsize, 4, 1, outfh);
+               fwrite(&dds_height, 4, 1, outfh);
+               fwrite(&dds_width, 4, 1, outfh);
+               fwrite(&dds_picsize, 4, 1, outfh);
                fwrite(&zero, 4, 1, outfh);
                fwrite(&dds_mipcount, 4, 1, outfh);
 
@@ -623,7 +628,7 @@ int main(int argc, char **argv)
                fwrite(&zero, 4, 1, outfh);
                fwrite(&zero, 4, 1, outfh);
                fwrite(&zero, 4, 1, outfh);
-               fwrite(&dds_format_size, 4, 1, outfh);
+               fwrite("\x20\x00\x00\x00", 4, 1, outfh);
                fwrite(alphapixels ? "\x05\x00\x00\x00" : "\x04\x00\x00\x00", 4, 1, outfh);
                fwrite(fourcc, 4, 1, outfh);
                fwrite(&zero, 4, 1, outfh);