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Frank76
04-29-2006, 02:18 PM
Hi, I found a 32x32 bitmap matrix on an array on the opengl-redbook. I'm trying to make sense of it. The array is from the sample polys.c
There is a diagram that shows the map, and I think I understood that x03 would do the following would turn 1 and 2 0000 0011 but I'm trying to follow the matrix to see, if I were going to draw on that paper, how would I interpret that.

* *
1 2 4 8 16 32 .... 128

this is the array. thanks
GLubyte fly[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x03, 0x80, 0x01, 0xC0, 0x06, 0xC0, 0x03, 0x60,
0x04, 0x60, 0x06, 0x20, 0x04, 0x30, 0x0C, 0x20,
0x04, 0x18, 0x18, 0x20, 0x04, 0x0C, 0x30, 0x20,
0x04, 0x06, 0x60, 0x20, 0x44, 0x03, 0xC0, 0x22,
0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22,
0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22,
0x44, 0x01, 0x80, 0x22, 0x44, 0x01, 0x80, 0x22,
0x66, 0x01, 0x80, 0x66, 0x33, 0x01, 0x80, 0xCC,
0x19, 0x81, 0x81, 0x98, 0x0C, 0xC1, 0x83, 0x30,
0x07, 0xe1, 0x87, 0xe0, 0x03, 0x3f, 0xfc, 0xc0,
0x03, 0x31, 0x8c, 0xc0, 0x03, 0x33, 0xcc, 0xc0,
0x06, 0x64, 0x26, 0x60, 0x0c, 0xcc, 0x33, 0x30,
0x18, 0xcc, 0x33, 0x18, 0x10, 0xc4, 0x23, 0x08,
0x10, 0x63, 0xC6, 0x08, 0x10, 0x30, 0x0c, 0x08,
0x10, 0x18, 0x18, 0x08, 0x10, 0x00, 0x00, 0x08};

Ehsan Kamrani
04-29-2006, 02:34 PM
To convert These values to the binary values, you should write 4 values for aech of the above values. So as an example, 0x05 == ( 00000101) in binary mode.Each 1 fills the bitmap image, while each 0 does not draw anything in your bitmap image. try to write these binary values after eachother and line by line. Then you can see the result. As an example, here's the second line:
0x03, 0x80, 0x01, 0xC0, 0x06, 0xC0, 0x03, 0x60
And here's the equivalent binary values:
00000011 1000000 00000001 11000000 00000110 11000000 00000011 01100000
or without spaces you get the following result:
00000011100000000000001110000000000011011000000 0000001101100000
Make sense?

-Ehsan-