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[dbjohn]

I found that the first 2 tutorials were very good. To be honest I thought the third tutorial got too advanced too quickly. Specifically some points I only half understood. It is possible that fairly experienced programmers found it okay as they had a familarity with the concepts. But some of the topics touched require a slower treatment in order for it to be grasped by the beginner. So I was wondering if anyone could recommend an online tutorial or text reference that would cover assembly language graphics or the creator of the video tutorials could share a specific source or reference that covers that area. I can find some tutorials on assembly language on the net but none that cover graphics.

[Neo]

Unfortunately, graphics fundamentals seem to be overlooked just about everywhere.  I haven't seen much since the late 90's on drawing in image buffers, and it's pretty useful for generating plots and such, which is one of the reasons I wanted to cover it.

Which points did you find confusing?  e.g. was it the image representation, the function calling, or the condition flags?

[dbjohn]

In the first few minutes the image representation didn't click for me e.g. index(x,y) = y*width+x. What is width, the width of the image we want to put in, the width of the pixels, the width of the fixed number of pixels...? Again I reiterate either the video goes at a slower pace or at least give a reference to online text that makes these details obvious.

[Neo]

Okay.  To explain that particular point, the image is just a 2D array of integers.  If a 2D array is stored in a contiguous block of memory in "row-major" order, the corresponding 1D index of the 2D index [row][col] is [row*numCols+col]:

0	1	2	3	...	numCols-1
numCols+0	numCols+1	numCols+2	numCols+3	...	numCols+(numCols-1)
2*numCols+0	2*numCols+1	2*numCols+2	2*numCols+3	...	2*numCols+(numCols-1)
3*numCols+0	3*numCols+1	3*numCols+2	3*numCols+3	...	3*numCols+(numCols-1)
...	...	...	...	...	...
(numRows-1)*numCols+0	(numRows-1)*numCols+1	(numRows-1)*numCols+2	(numRows-1)*numCols+3	...	(numRows-1)*numCols+(numCols-1)

In the case of an image, x=col, y=row, width=numCols, height=numRows.  Would that clear things up?

[dbjohn]

Yes that helps. That is what I thought he was trying to say. So index(x,y) is the starting index of the image.

[Neo]

When I eventually get around to remaking the videos (probably after Inventor IDE Alpha 6 is finally out), I'll try to remember to clarify it.  Thanks for the input!