Graphics Programming
TVP4020
Programmers Reference Manual
56
// Set the Rasterizer mode to the default, see
// §5.3.11
RasterizerMode (0)
// Set-up the start values and the deltas.
// Note that the X and Y coordinates are converted to
// 16.16 format
StartXDom (X<<16)
dXDom (0)
StartXSub ((X + 5)<<16) // Right hand edge pixels get
// missed off.
StartY (Y<<16)
dY (1<<16)
Count (8)
// At least the following bits require setting for the
// Render command.
render.PrimitiveType = PERMEDIA_TRAPEZOID_PRIMITIVE
render.SyncOnBitMask = PERMEDIA_TRUE
render.ReuseBitMask = PERMEDIA_FALSE
// Issue render command. First fragment will be
// generated on receipt of the BitMaskPattern
Render (render)
// 8x5 pixel bitmap requires 40 bits, and so 2
// 32 bit words.
BitMaskPattern (patternWord0)
BitMaskPattern (patternWord1)
Rendering will start as soon as the first patternWord is loaded into the
BitMaskPattern register.
5.3.9
Block Writes and Bitmaps
The fastest way to render downloaded bitmap data, not requiring logical
op processing, is to use block fills. The Rasterizer is set-up as normal
setting the FastFillEnable bit. If it is necessary to also plot the
background color then, the operation should be repeated for the
background color but with the InvertBitMask bit set in the
RasterizerMode register.
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 ...