annotate stitch/draw.c @ 0:5242703e91d3 tip

Initial checkin for AIM92 aimR8.2 (last updated May 1997).

/*
    Copyright (c) Applied Psychology Unit, Medical Research Council. 1988, 1989
    ===========================================================================

    Permission to use, copy, modify, and distribute this software without fee 
    is hereby granted for research purposes, provided that this copyright 
    notice appears in all copies and in all supporting documentation, and that 
    the software is not redistributed for any fee (except for a nominal shipping 
    charge). Anyone wanting to incorporate all or part of this software in a
    commercial product must obtain a license from the Medical Research Council.

    The MRC makes no representations about the suitability of this 
    software for any purpose.  It is provided "as is" without express or implied 
    warranty.
 
    THE MRC DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING 
    ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL THE
    A.P.U. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY 
    DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 
    AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

/*
    draw.c
    ======

    basic interface between file format and windows content

*/

/*  Added the field nwid in the '_draw_state' object.  AJD 17-3-95 */
 
#include <math.h>

#include "windows.h"
#include "stitch.h"
#include "source.h"
#include "draw.h"
#include "ops.h"

#ifndef lint
static char *draw_sccs_id = "@(#)draw.c	1.15 John Holdsworth (MRC-APU) 6/6/91" ;
#endif

/* maximum buffer size for segmentation of drawing */

#if defined( PC ) || defined( THINK_C )
#define MAX_BUFFER (1l<<14)
#else
#define MAX_BUFFER (1l<<16)
#endif

/* globale variable for display paramters */

double drawHeadroom = 0.0 ;
double drawTilt     = 0.0 ;
double drawDepth    = 0.0 ;
double drawDistance = 0.5 ;
double drawOverlap = 0.0 ;

/*

    this mess is worth a comment

    I'd like to apologise for the moras of scaling parameters for display
    .. the price of backward compatability.

    Originally you could tillt the diaply to give the sensation of depth,
    then the display parameters where changed to min, max and overlap.
    The result is the combination of the two. At least the new interface
    is a bit cleaner from the outside.

    There is also the complication of segmented drawing across and down
    the screen. All in all this needs to be rewritten!

    From the outside though it's interface is reasonably clean however.

    if framewidth > 1 then it's a 2d image per frame. If not then its
    a multiplexed file.

*/


void draw_frame( state, frame )
struct _draw_state *state ;
short *frame ;
{
    double sintheta = sin( drawTilt / 45. * atan( 1. ) ) ;
    double scale = ( 100. - drawHeadroom ) / 100. / ( drawDistance / ( drawDistance + sintheta ) ) ;
    double height = Height( state->window ) * ( 1. - drawHeadroom / 100. ) ;
    double overscale, rowscale, origin ;
    int row ;

    for( row=state->frameheight-1 ; row >= 0 ; row-- ) {

	rowscale = drawDistance / ( drawDistance + sintheta * ( row + 0.5 ) / state->frameheight ) ;
	overscale = 1. / ( ( state->frameheight - 1. ) * ( 1. - drawOverlap ) + 1. ) ;
	origin = row * height * overscale * ( 1. - drawOverlap ) +
    ( 0. - state->min ) / ( state->max - state->min ) * Height( state->window ) * overscale ;

	if( state->framewidth > 1 )
	    Function(     state->window, frame+row*state->framewidth, state->framewidth,                     1, origin * rowscale * scale, ( state->max - state->min ) / overscale / rowscale ) ;
	else
	    if( state->colnumber == 0 )
		Segment(  state->window, frame+row,                    state->colsegment,   state->frameheight, origin * rowscale * scale, ( state->max - state->min ) / overscale / rowscale, state->colnumber,   (int) state->frames ) ;
	    else
		Segment(  state->window, frame+row-state->frameheight, state->colsegment+1, state->frameheight, origin * rowscale * scale, ( state->max - state->min ) / overscale / rowscale, state->colnumber-1, (int) state->frames ) ;
    }

    return ;
}


static void draw_callback( state, bytes, buffer )
struct _draw_state *state ;
ByteCount *bytes ;
short *buffer ;
{
    int first = state->colnumber == 0 ;

    if( state->framewidth > 1 ) {
	state->rowsegment = *bytes / sizeof ( short ) / state->framewidth  ;
	if( state->rowsegment > state->frameheight - state->rownumber )
	    state->rowsegment = state->frameheight - state->rownumber ;
    }
    else {
	state->colsegment = *bytes / sizeof ( short ) / state->frameheight ;
	if( state->colsegment > state->frames - state->colnumber )
	    state->colsegment = state->frames - state->colnumber ;
    }

    if( first )
	++state->framenumber ;

    if( *bytes != 0 )
	state->interceptor( state, buffer, first ) ;

    if( state->framewidth > 1 )
	state->rownumber = ( state->rownumber + state->rowsegment ) % state->frameheight ;
    else
	state->colnumber = ( state->colnumber + state->colsegment ) % state->frames ;

}

Source SourceDraw( source, min, max, window, framewidth, frameheight, nwid, frames, interceptor, drawer )
Source source ;
int min, max ;
WindowObject window ;
int framewidth, frameheight ;
int nwid;
long frames ;
void (*interceptor)() ;
void (*drawer)() ;
{
    DeclareNew( struct _draw_state *, state ) ;
    int segsize ;

    state->min = min ;
    state->max = max ;

    state->source = source ;
    state->window = window ;

    state->frameheight = frameheight ;
    state->framewidth  = framewidth ;
    state->nwid = nwid ;
    state->frames      = frames ;

    state->framenumber = 0 ;

    state->colnumber  = 0 ;
    state->rownumber  = 0 ;

    state->colsegment = framewidth ;
    state->rowsegment = frameheight ;

    state->interceptor = interceptor ;
    state->drawer      = drawer ;

    source = NewTappingSource( state, draw_callback, stitch_free, source, "draw.c drawing" ) ;

    if( state->framewidth == 1 ) {

	segsize = MAX_BUFFER / frameheight / sizeof ( short ) - 1 ;

	if( segsize > frames )
	    segsize = frames ;
	else
	    source = NewRetainingSource( source, frameheight * sizeof ( short ) ) ;

	source = NewBlockingSource(      source, frameheight * sizeof ( short ) * segsize ) ;
    }

    return ( source ) ;
}

static Source DrawEither( window, source, min, max, framepoints, nwid, frames, drawer, row_flag )
WindowObject window ;
Source source ;
int min, max ;
int framepoints, frames, nwid ;
int row_flag ;
void (*drawer)() ;
{
    void (*draw_routine)() = drawer ;

    if( draw_routine == (void ( * )()) 0 )
	draw_routine = draw_frame ;

    return ( SourceDraw( source, min, max, window, 1, framepoints, nwid, (long) frames, draw_routine, draw_routine ) ) ;
}

Source drawAcross(       window, source, min, max, framepoints, nwid, frames, drawer )
WindowObject window ;
Source source ;
int min, max ;
int framepoints, frames ;
void (*drawer)() ;
{
    return ( DrawEither( window, source, min, max, framepoints, nwid, frames, drawer, 0 ) ) ;
}

Source drawDown(         window, source, min, max, framepoints, nwid, frames, drawer )
WindowObject window ;
Source source ;
int min, max ;
int framepoints, frames ;
void (*drawer)() ;
{
    return ( DrawEither( window, source, min, max, framepoints, nwid, frames, drawer, 1 ) ) ;
}