quixotic project blog

It has been a while since I last used Vertex Buffer Objects (VBO) with LWJGL. It seemed as if they had changed some of the method signatures since I used them last time. I couldn’t even get the simplest example running. After experimenting for a while I finally figured it out. Have a look at the signature of the VertexPointer method:

static void glVertexPointer(int size, int type,
  int stride, long pointer_buffer_offset);

With the last offset one can specify where the vertex information starts in the buffer given to the VBO management. Well, I could/should have guessed that this offset has to be in bytes since I am dealing with a buffer here but instead I used the number of floats.. So next time I see an operation dealing with buffers that takes a long argument I’ll try the byte-count from the beginning..

If you are using Meggy Jr with the Serial-to-USB Cable provided in the Evil Mad Scientist shop you might encounter the following error:

avrdude: stk500_getsync(): not in sync: resp=0×00
avrdude: stk500_disable(): protocol error, expect=0×14, resp=0×51

The error manifest while uploading a new sketch to Meggy. If you pull out the USB cable and plug it in again you can upload a sketch successful. But on the next time you try you’ll get the error again. Luckily there is a pretty simple solution. I found it while digging through the Evil Mad Scientist Forums. It involves setting the “Set RTS on close” flag of the COM Port. You can do this in the Device Manager. Find the COM Port that was installed when you first plugged in the USB-to-Serial cable. For me it’s COM3. In the connection settings click on details and mark the flag selected. That’s it. I tried this on Windows XP with Service Pack 3, but it should work similiarily on other Windows versions.

RTS Flag