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TVP4020
Programmers Reference Manual
Graphics Programming
125
Stencil
6
7
This is the data from image upload of the
Stencil buffer.
Color
8
9
This is the data from image upload of the
Framebuffer (FBColor).
Synchronization
10
11
Statistics
12
13
This is the data generated following a
command to read back the results of the
statistic measurements: PickResult,
MaxHitRegion, MinHitRegion
Reserved
14
15
Table 5.21
Filter Modes
Note, the filter unit must be set appropriately before any synchronization
can take place.
5.15.2
Statistic Operations
There are two statistic collection modes of operation; picking and extent
checking. Picking is normally used to select drawn objects or regions of
the screen. Typically, extent checking is used to determine the bounds
within which drawing has occurred so that a smaller area of the
framebuffer can subsequently be cleared.
Statistic collection is controlled using the StatisticMode register.
Picking
In picking mode, the active and/or passive fragments have their
associated XY coordinates compared against the coordinates specified
in the MinRegion and MaxRegion registers. If the result is true, then the
PickResult flag is set, otherwise it holds its previous state. The compare
function can be either Inside or Outside. Before picking can start, the
ResetPickResult register must be loaded to clear the PickResult flag.
The MinRegion and MaxRegion registers are loaded to select the region
of interest for picking. A coordinate is inside the region if:
X
min
≤
X
<
X
max
Y
min
≤
Y
<
Y
max
where X and Y are from the fragment and the min/max values are from
MinRegion and MaxRegion registers. This comparison is identical to the
one used in the scissor tests.
The following stages are required for picking:
1) load ResetPickResult, MinRegion and MaxRegion registers
2) Set-up the FilterMode to allow statistic commands out of P
ERMEDIA
Summary of Contents for TVP4020 PERMEDIA 2
Page 1: ...Texas Instruments TVP4020 PERMEDIA 2 Programmer s Reference Manual Issue 4 ...
Page 284: ...TVP4020 Programmers Reference Manual A Gouraud Shaded Triangle 275 ...
Page 292: ...TVP4020 Programmers Reference Manual Register Tables 283 ...
Page 314: ...TVP4020 Programmers Reference Manual Index 305 ...
Page 315: ...Index TVP4020 Programmers Reference Manual 306 Index ...
Page 323: ...Index TVP4020 Programmers Reference Manual 314 ...