Graphics Programming
TVP4020
Programmers Reference Manual
104
The FBReadPixel sets the pixel size.
0
8
16
24
31
Reserved
Pixel Size
Figure 5.35
FBReadPixel Register
The PackedDataLimits register is used to control packed copies.
0
8
16
24
31
12 bit integer XStart
Not used
12 bit integer XEnd
Reserved
RelativeOffset
Figure 5.36
PackedDataLimits Register
FBHardwareWriteMask is a 32bit register where each bit acts as a mask.
FBColor is a read-only register which returns the data to the host during
image upload operations.
5.10.10 Image Copy Example
This example copies a rectangular region of the framebuffer, without
moving any data in the localbuffer. The region extends from the origin
(0,0) to (100,100) and will be shifted right by 200 pixels. The destination
rectangle is scan converted.
// First set-up the framebuffer read mode
fbReadMode.ReadSource = PERMEDIA_ENABLE
fbReadMode.ReadDestination = PERMEDIA_DISABLE
fbReadMode.DataType = PERMEDIA_FBDEFAULT
FBReadMode(fbReadMode) // Update register
// Now enable framebuffer writefbWriteMode.WriteEnable = PERMEDIA_ENABLE
FBWriteMode(fbWriteMode) // Update register
// Offsets. No Pixel offset, source offset of 200
FBPixelOffset (0x0)
FBSourceOffset (-200)
// All the tests which could remove the fragment must be
// disabled (Stipple, Stencil, Depth) except
// the Scissor test which is still needed for screen
// and possibly window clipping.
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 ...