static octree_node_t* find_leaf(octree_node_t* root,
bbox_t* bounding_box,
point_t* x)
{
if (!bbox_contains(bounding_box, x))
return NULL;
return NULL;
}
/**
* bd_blockReader is called repeatedly after bd_readerNext to read the contents
* of a backdrop block. It returns a bounded area with color and info, or null
* indicating the block has been read.
*/
const dbbox_t *bd_blockReader(CompositeContext *context,
const Backdrop *backdrop,
uint8 **color8, COLORVALUE **color,
COLORINFO **info)
{
BackdropReader *reader = &context->reader;
dbbox_t *bounds = &reader->bounds;
uint8 slot;
HQASSERT(reader->block != NULL, "Must have a block to read");
HQASSERT(!bd_isPurgeable(reader->block) && reader->block->lines != NULL &&
(bd_isUniform(reader->block) || reader->block->data != NULL),
"Block is not suitable for reading");
if ( reader->blockFinish ) {
return NULL;
} else if ( reader->blockStart ) {
reader->blockStart = FALSE;
/* Calculate the read bounds for this block. */
bbox_store(&reader->readBoundsForBlock, reader->xTopLeft, reader->yTopLeft,
reader->xTopLeft + bd_blockWidth(reader->block) - 1,
reader->yTopLeft + bd_blockHeight(reader->block) - 1);
bbox_intersection(&reader->readBoundsForBlock, &reader->readBounds,
&reader->readBoundsForBlock);
HQASSERT(!bbox_is_empty(&reader->readBoundsForBlock) &&
bbox_contains(&reader->readBounds, &reader->readBoundsForBlock),
"readBoundsForBlock is invalid");
/* Check for a uniform block. */
if ( bd_isUniform(reader->block) ) {
bdt_getOutput(bd_uniformTable(reader->block), backdrop->outComps, 0,
color, color8, info);
reader->blockFinish = TRUE;
return &reader->readBoundsForBlock;
}
/* Initialise bounds for the first read from this block (x1/x2 are set to
xTopLeft rather than readBoundsForBlock.x1 to handle the RLE case below). */
bounds->x1 = bounds->x2 = reader->xTopLeft;
bounds->y1 = bounds->y2 = reader->readBoundsForBlock.y1;
} else {
/* Already reading from the block so just advance to the next pixel. */
bounds->x1 = bounds->x2 = bounds->x2 + 1;
if ( bounds->x1 > reader->readBoundsForBlock.x2 ) {
/* Reached end of line; go to the next. */
bounds->x1 = bounds->x2 = reader->xTopLeft;
bounds->y1 = bounds->y2 = bounds->y2 + 1;
if ( bounds->y1 > reader->readBoundsForBlock.y2 ) {
/* No more lines in this block; get the next block. */
reader->blockFinish = TRUE;
return NULL;
}
}
}
/* Check for a start of a line. */
if ( bounds->x1 == reader->xTopLeft ) {
int32 xSkip = reader->readBoundsForBlock.x1 - reader->xTopLeft;
bd_lineAndDataRepeatSrc(reader->block, bounds->y1 - reader->yTopLeft,
&reader->line, &reader->data);
/* Skip pixels before readBoundsForBlock.x1. */
if ( xSkip > 0 ) {
if ( bd_isRLE(reader->line) ) {
while ( (bounds->x1 + readRunLen(reader->data[0]) - 1)
< reader->readBoundsForBlock.x1 ) {
bounds->x1 += readRunLen(reader->data[0]);
reader->data += 2;
}
} else {
bounds->x1 += xSkip;
reader->data += xSkip;
}
bounds->x2 = bounds->x1;
}
/* Count repeated lines. */
for ( ; bounds->y2 < reader->readBoundsForBlock.y2 &&
reader->block->lines[bounds->y2 + 1 - reader->yTopLeft].repeat;
++bounds->y2 ) {
EMPTY_STATEMENT();
}
}
HQASSERT(bounds->x1 == bounds->x2, "x1 and x2 should be the same");
if ( bd_isRLE(reader->line) ) {
/* Already got RLE; just read the next run. */
slot = reader->data[1];
bounds->x2 += readRunLen(reader->data[0]) - 1;
bbox_clip_x(&reader->readBoundsForBlock, bounds->x1, bounds->x2);
reader->data += 2;
} else {
/* Got a map, but check for runs. */
slot = reader->data[0];
++reader->data;
while ( bounds->x2 < reader->readBoundsForBlock.x2 &&
reader->data[0] == slot ) {
++bounds->x2;
++reader->data;
}
}
HQASSERT(!bbox_is_empty(bounds) &&
bbox_contains(&reader->readBoundsForBlock, bounds), "Invalid bounds");
bdt_getOutput(reader->line->table, backdrop->outComps, slot,
color, color8, info);
return bounds;
}
