An open source, cross-platform, OpenGL tutor.

Step Mode

Glitch provides an alternative program mode called step(per) mode. This mode behaves similar to a debugger, enabling the you to step through commands and see how they affect both the scene output and also the model view and projection matrices.

Step mode can be enabled by checking the "Step through display" option box, which is located under the "Program Mode" tab.

Below is a screenshot of Glitch, with a mark indicating where the step mode controls are located.

Below is another screenshot of Glitch, here with the step mode enabled. Click on one of the circled numbers to find out more about a given part of the main window.

1. Step through display

Use this check box to enable / disable the step mode for the display section. The associated controls will be enabled / disabled as appropriate with the checking of this box.


2. Reset

Reset the stepper back to position 0, which is just before the first display command (but after the initialization commands).


3. Previous

Step back to the previous step position, unless you are already at position 0.


4. Next

Step forwards to the next step position / display command, unless you are at the last one.


5. Stepper Progress

This indicates the current progress of the stepper, where the first number is the position and the second is the total number of display commands.


6. Current Transformation Matrix

This indicates the current matrix mode at the current step position, which in Glitch can be either Model View or Projection. To view the contents of the CTM, choose to Show the matrix that is listed here and then look at the Matrix Values.


7. Show Matrix

This allows you to choose which Matrix Values to show, be it from the Model View matrix or the Projection matrix.


8. Matrix Values

This box displays the current 4x4 matrix values from either the Model View or Projection matrices, as selected by Show Matrix for the current step position.


9. Stepper Position Highlight

The current stepper position will be highlighted in the Display table. The obvious exception is position 0, where we haven't stepped into the display commands yet.