Project:USB Disco Dance Floor/v1/firmware: Difference between revisions
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Project:USB Disco Dance Floor/v1/firmware (view source)
Revision as of 08:50, 7 April 2011
, 7 April 2011Added details about ordering
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A scroll spec consists of two two-bit values and two one-bit values packed into a single byte, with the bit pattern: <tt>xxyy0w0h</tt>. The number of pixels to scroll along the X and Y axes is specified by <tt>xx</tt> and <tt>yy</tt>, and the direction is negative along the X/Y axis if <tt>w</tt> or <tt>h</tt> are set, respectively. | A scroll spec consists of two two-bit values and two one-bit values packed into a single byte, with the bit pattern: <tt>xxyy0w0h</tt>. The number of pixels to scroll along the X and Y axes is specified by <tt>xx</tt> and <tt>yy</tt>, and the direction is negative along the X/Y axis if <tt>w</tt> or <tt>h</tt> are set, respectively. | ||
=== Ordering === | |||
When commands refer to regions of the floor and some ordering of the data is needed it will be sorted in a fixed format, with the X co-ordinate increasing until it would fall outside the region. The X co-ordinate is then reset and the Y co-ordinate increased by 1, until the region is defined. | |||
For example, the region: (1, 0) to (2, 2) would be ordered as follows: (1, 0), (2, 0), (1, 1), (2, 1), (1, 2), (2, 2). The code for this algorithm might look something like: | |||
for j in range(y, h+1): | |||
for i in range(x, w+1): | |||
output(pixel[x][y]) | |||
and going back the other way: | |||
<!-- TODO: check this code --> | |||
pos=0 | |||
while (col = read()): | |||
i = x + (pos % (w-x)) | |||
j = y + (pos / (h-y)) | |||
pixel[x][y] = col | |||
== Commands == | == Commands == | ||
