Add DXT1 div table generator.

extra/dxt1divtable.c

@@ -0,0 +1,22 @@
+#include <stdint.h>
+#include <stdio.h>
+
+int main()
+{
+    for( int i=0; i<255*3; i++ )
+    {
+        // replace 4 with 2 for ARM NEON table
+        uint32_t range = ( 4 << 16 ) / ( 1+i );
+        if( range > 0xFFFF ) range = 0xFFFF;
+        if( i % 16 == 15 )
+        {
+            printf( "0x%04x,\n", range );
+        }
+        else
+        {
+            printf( "0x%04x, ", range );
+        }
+    }
+    printf( "\n" );
+    return 0;
+}