1	// Copyright (C) 2016 The Qt Company Ltd.
2	// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4	/***************************************************************************/
5	/* */
6	/* qgrayraster.c, derived from ftgrays.c */
7	/* */
8	/* A new `perfect' anti-aliasing renderer (body). */
9	/* */
10	/* Copyright 2000-2016 by */
11	/* David Turner, Robert Wilhelm, and Werner Lemberg. */
12	/* */
13	/* This file is part of the FreeType project, and may only be used, */
14	/* modified, and distributed under the terms of the FreeType project */
15	/* license, ../../3rdparty/freetype/docs/FTL.TXT. By continuing to use, */
16	/* modify, or distribute this file you indicate that you have read */
17	/* the license and understand and accept it fully. */
18	/* */
19	/***************************************************************************/
20
21	/*************************************************************************/
22	/* */
23	/* This file can be compiled without the rest of the FreeType engine, by */
24	/* defining the _STANDALONE_ macro when compiling it. You also need to */
25	/* put the files `ftgrays.h' and `ftimage.h' into the current */
26	/* compilation directory. Typically, you could do something like */
27	/* */
28	/* - copy `src/smooth/ftgrays.c' (this file) to your current directory */
29	/* */
30	/* - copy `include/freetype/ftimage.h' and `src/smooth/ftgrays.h' to the */
31	/* same directory */
32	/* */
33	/* - compile `ftgrays' with the _STANDALONE_ macro defined, as in */
34	/* */
35	/* cc -c -D_STANDALONE_ ftgrays.c */
36	/* */
37	/* The renderer can be initialized with a call to */
38	/* `qt_ft_gray_raster.raster_new'; an anti-aliased bitmap can be generated */
39	/* with a call to `qt_ft_gray_raster.raster_render'. */
40	/* */
41	/* See the comments and documentation in the file `ftimage.h' for more */
42	/* details on how the raster works. */
43	/* */
44	/*************************************************************************/
45
46	/*************************************************************************/
47	/* */
48	/* This is a new anti-aliasing scan-converter for FreeType 2. The */
49	/* algorithm used here is _very_ different from the one in the standard */
50	/* `ftraster' module. Actually, `ftgrays' computes the _exact_ */
51	/* coverage of the outline on each pixel cell. */
52	/* */
53	/* It is based on ideas that I initially found in Raph Levien's */
54	/* excellent LibArt graphics library (see http://www.levien.com/libart */
55	/* for more information, though the web pages do not tell anything */
56	/* about the renderer; you'll have to dive into the source code to */
57	/* understand how it works). */
58	/* */
59	/* Note, however, that this is a _very_ different implementation */
60	/* compared to Raph's. Coverage information is stored in a very */
61	/* different way, and I don't use sorted vector paths. Also, it doesn't */
62	/* use floating point values. */
63	/* */
64	/* This renderer has the following advantages: */
65	/* */
66	/* - It doesn't need an intermediate bitmap. Instead, one can supply a */
67	/* callback function that will be called by the renderer to draw gray */
68	/* spans on any target surface. You can thus do direct composition on */
69	/* any kind of bitmap, provided that you give the renderer the right */
70	/* callback. */
71	/* */
72	/* - A perfect anti-aliaser, i.e., it computes the _exact_ coverage on */
73	/* each pixel cell. */
74	/* */
75	/* - It performs a single pass on the outline (the `standard' FT2 */
76	/* renderer makes two passes). */
77	/* */
78	/* - It can easily be modified to render to _any_ number of gray levels */
79	/* cheaply. */
80	/* */
81	/* - For small (< 20) pixel sizes, it is faster than the standard */
82	/* renderer. */
83	/* */
84	/*************************************************************************/
85
86	/*************************************************************************/
87	/* */
88	/* The macro QT_FT_COMPONENT is used in trace mode. It is an implicit */
89	/* parameter of the QT_FT_TRACE() and QT_FT_ERROR() macros, used to print/log */
90	/* messages during execution. */
91	/* */
92	#undef QT_FT_COMPONENT
93	#define QT_FT_COMPONENT trace_smooth
94
95
96	/* Auxiliary macros for token concatenation. */
97	#define QT_FT_ERR_XCAT( x, y ) x ## y
98	#define QT_FT_ERR_CAT( x, y ) QT_FT_ERR_XCAT( x, y )
99
100	#define QT_FT_BEGIN_STMNT do {
101	#define QT_FT_END_STMNT } while ( 0 )
102
103	#define QT_FT_MAX( a, b ) ( (a) > (b) ? (a) : (b) )
104	#define QT_FT_ABS( a ) ( (a) < 0 ? -(a) : (a) )
105
106
107	/*
108	* Approximate sqrt(x*x+y*y) using the `alpha max plus beta min'
109	* algorithm. We use alpha = 1, beta = 3/8, giving us results with a
110	* largest error less than 7% compared to the exact value.
111	*/
112	#define QT_FT_HYPOT( x, y ) \
113	( x = QT_FT_ABS( x ), \
114	y = QT_FT_ABS( y ), \
115	x > y ? x + ( 3 * y >> 3 ) \
116	: y + ( 3 * x >> 3 ) )
117
118	#define ErrRaster_MemoryOverflow -4
119
120	#if defined(VXWORKS)
121	# include <vxWorksCommon.h> /* needed for setjmp.h */
122	#endif
123	#include <string.h> /* for qt_ft_memcpy() */
124	#include <setjmp.h>
125	#include <limits.h>
126
127	#define QT_FT_UINT_MAX UINT_MAX
128
129	#define qt_ft_memset memset
130
131	#define qt_ft_setjmp setjmp
132	#define qt_ft_longjmp longjmp
133	#define qt_ft_jmp_buf jmp_buf
134
135	#include <stddef.h>
136	typedef ptrdiff_t QT_FT_PtrDist;
137
138	#define ErrRaster_Invalid_Mode -2
139	#define ErrRaster_Invalid_Outline -1
140	#define ErrRaster_Invalid_Argument -3
141	#define ErrRaster_Memory_Overflow -4
142	#define ErrRaster_OutOfMemory -6
143
144	#define QT_FT_BEGIN_HEADER
145	#define QT_FT_END_HEADER
146
147	#include <private/qrasterdefs_p.h>
148	#include <private/qgrayraster_p.h>
149
150	#include <qcompilerdetection.h>
151
152	#include <stdlib.h>
153	#include <stdio.h>
154	#include <assert.h>
155
156	#define QT_FT_UNUSED( x ) (void) x
157
158	#define QT_FT_TRACE5( x ) do { } while ( 0 ) /* nothing */
159	#define QT_FT_TRACE7( x ) do { } while ( 0 ) /* nothing */
160	#define QT_FT_ERROR( x ) do { } while ( 0 ) /* nothing */
161	#define QT_FT_THROW( e ) QT_FT_ERR_CAT( ErrRaster_, e )
162
163	#ifndef QT_FT_MEM_SET
164	#define QT_FT_MEM_SET( d, s, c ) qt_ft_memset( d, s, c )
165	#endif
166
167	#ifndef QT_FT_MEM_ZERO
168	#define QT_FT_MEM_ZERO( dest, count ) QT_FT_MEM_SET( dest, 0, count )
169	#endif
170
171
172	#define RAS_ARG PWorker worker
173	#define RAS_ARG_ PWorker worker,
174
175	#define RAS_VAR worker
176	#define RAS_VAR_ worker,
177
178	#define ras (*worker)
179
180	/* must be at least 6 bits! */
181	#define PIXEL_BITS 8
182
183	#define ONE_PIXEL ( 1L << PIXEL_BITS )
184	#define TRUNC( x ) (TCoord)( (x) >> PIXEL_BITS )
185	#define FRACT( x ) (TCoord)( (x) & ( ONE_PIXEL - 1 ) )
186
187	#if PIXEL_BITS >= 6
188	#define UPSCALE( x ) ( (x) * ( ONE_PIXEL >> 6 ) )
189	#define DOWNSCALE( x ) ( (x) >> ( PIXEL_BITS - 6 ) )
190	#else
191	#define UPSCALE( x ) ( (x) >> ( 6 - PIXEL_BITS ) )
192	#define DOWNSCALE( x ) ( (x) * ( 64 >> PIXEL_BITS ) )
193	#endif
194
195	/* Compute `dividend / divisor' and return both its quotient and */
196	/* remainder, cast to a specific type. This macro also ensures that */
197	/* the remainder is always positive. */
198	#define QT_FT_DIV_MOD( type, dividend, divisor, quotient, remainder ) \
199	QT_FT_BEGIN_STMNT \
200	(quotient) = (type)( (dividend) / (divisor) ); \
201	(remainder) = (type)( (dividend) % (divisor) ); \
202	if ( (remainder) < 0 ) \
203	{ \
204	(quotient)--; \
205	(remainder) += (type)(divisor); \
206	} \
207	QT_FT_END_STMNT
208
209	/* These macros speed up repetitive divisions by replacing them */
210	/* with multiplications and right shifts. */
211	#define QT_FT_UDIVPREP( b ) \
212	long b ## _r = (long)( ULONG_MAX >> PIXEL_BITS ) / ( b )
213	#define QT_FT_UDIV( a, b ) \
214	( ( (unsigned long)( a ) * (unsigned long)( b ## _r ) ) >> \
215	( sizeof( long ) * CHAR_BIT - PIXEL_BITS ) )
216
217
218	/*************************************************************************/
219	/* */
220	/* TYPE DEFINITIONS */
221	/* */
222
223	/* don't change the following types to QT_FT_Int or QT_FT_Pos, since we might */
224	/* need to define them to "float" or "double" when experimenting with */
225	/* new algorithms */
226
227	typedef long TCoord; /* integer scanline/pixel coordinate */
228	typedef long TPos; /* sub-pixel coordinate */
229	typedef long TArea ; /* cell areas, coordinate products */
230
231	/* maximal number of gray spans in a call to the span callback */
232	#define QT_FT_MAX_GRAY_SPANS 256
233
234
235	typedef struct TCell_* PCell;
236
237	typedef struct TCell_
238	{
239	int x;
240	int cover;
241	TArea area;
242	PCell next;
243
244	} TCell;
245
246
247	typedef struct TWorker_
248	{
249	TCoord ex, ey;
250	TPos min_ex, max_ex;
251	TPos min_ey, max_ey;
252	TPos count_ex, count_ey;
253
254	TArea area;
255	int cover;
256	int invalid;
257
258	PCell cells;
259	QT_FT_PtrDist max_cells;
260	QT_FT_PtrDist num_cells;
261
262	TPos x, y;
263
264	QT_FT_Outline outline;
265	QT_FT_Bitmap target;
266	QT_FT_BBox clip_box;
267
268	QT_FT_Span gray_spans[QT_FT_MAX_GRAY_SPANS];
269	int num_gray_spans;
270
271	QT_FT_Raster_Span_Func render_span;
272	void* render_span_data;
273
274	int band_size;
275	int band_shoot;
276
277	qt_ft_jmp_buf jump_buffer;
278
279	void* buffer;
280	long buffer_size;
281
282	PCell* ycells;
283	TPos ycount;
284
285	int skip_spans;
286	} TWorker, *PWorker;
287
288
289	typedef struct TRaster_
290	{
291	void* buffer;
292	long buffer_size;
293	long buffer_allocated_size;
294	int band_size;
295	void* memory;
296	PWorker worker;
297
298	} TRaster, *PRaster;
299
300	int q_gray_rendered_spans(TRaster *raster)
301	{
302	if ( raster && raster->worker )
303	return raster->worker->skip_spans > 0 ? 0 : -raster->worker->skip_spans;
304	return 0;
305	}
306
307	/*************************************************************************/
308	/* */
309	/* Initialize the cells table. */
310	/* */
311	static void
312	gray_init_cells( RAS_ARG_ void* buffer,
313	long byte_size )
314	{
315	ras.buffer = buffer;
316	ras.buffer_size = byte_size;
317
318	ras.ycells = (PCell*) buffer;
319	ras.cells = NULL;
320	ras.max_cells = 0;
321	ras.num_cells = 0;
322	ras.area = 0;
323	ras.cover = 0;
324	ras.invalid = 1;
325	}
326
327
328	/*************************************************************************/
329	/* */
330	/* Compute the outline bounding box. */
331	/* */
332	static void
333	gray_compute_cbox( RAS_ARG )
334	{
335	QT_FT_Outline* outline = &ras.outline;
336	QT_FT_Vector* vec = outline->points;
337	QT_FT_Vector* limit = vec + outline->n_points;
338
339
340	if ( outline->n_points <= 0 )
341	{
342	ras.min_ex = ras.max_ex = 0;
343	ras.min_ey = ras.max_ey = 0;
344	return;
345	}
346
347	ras.min_ex = ras.max_ex = vec->x;
348	ras.min_ey = ras.max_ey = vec->y;
349
350	vec++;
351
352	for ( ; vec < limit; vec++ )
353	{
354	TPos x = vec->x;
355	TPos y = vec->y;
356
357
358	if ( x < ras.min_ex ) ras.min_ex = x;
359	if ( x > ras.max_ex ) ras.max_ex = x;
360	if ( y < ras.min_ey ) ras.min_ey = y;
361	if ( y > ras.max_ey ) ras.max_ey = y;
362	}
363
364	/* truncate the bounding box to integer pixels */
365	ras.min_ex = ras.min_ex >> 6;
366	ras.min_ey = ras.min_ey >> 6;
367	ras.max_ex = ( ras.max_ex + 63 ) >> 6;
368	ras.max_ey = ( ras.max_ey + 63 ) >> 6;
369	}
370
371
372	/*************************************************************************/
373	/* */
374	/* Record the current cell in the table. */
375	/* */
376	static PCell
377	gray_find_cell( RAS_ARG )
378	{
379	PCell *pcell, cell;
380	TPos x = ras.ex;
381
382
383	if ( x > ras.count_ex )
384	x = ras.count_ex;
385
386	pcell = &ras.ycells[ras.ey];
387	for (;;)
388	{
389	cell = *pcell;
390	if ( cell == NULL || cell->x > x )
391	break;
392
393	if ( cell->x == x )
394	goto Exit;
395
396	pcell = &cell->next;
397	}
398
399	if ( ras.num_cells >= ras.max_cells )
400	qt_ft_longjmp( ras.jump_buffer, val: 1 );
401
402	cell = ras.cells + ras.num_cells++;
403	cell->x = x;
404	cell->area = 0;
405	cell->cover = 0;
406
407	cell->next = *pcell;
408	*pcell = cell;
409
410	Exit:
411	return cell;
412	}
413
414
415	static void
416	gray_record_cell( RAS_ARG )
417	{
418	if ( ras.area | ras.cover )
419	{
420	PCell cell = gray_find_cell( RAS_VAR );
421
422
423	cell->area += ras.area;
424	cell->cover += ras.cover;
425	}
426	}
427
428
429	/*************************************************************************/
430	/* */
431	/* Set the current cell to a new position. */
432	/* */
433	static void
434	gray_set_cell( RAS_ARG_ TCoord ex,
435	TCoord ey )
436	{
437	/* Move the cell pointer to a new position. We set the `invalid' */
438	/* flag to indicate that the cell isn't part of those we're interested */
439	/* in during the render phase. This means that: */
440	/* */
441	/* . the new vertical position must be within min_ey..max_ey-1. */
442	/* . the new horizontal position must be strictly less than max_ex */
443	/* */
444	/* Note that if a cell is to the left of the clipping region, it is */
445	/* actually set to the (min_ex-1) horizontal position. */
446
447	/* All cells that are on the left of the clipping region go to the */
448	/* min_ex - 1 horizontal position. */
449	ey -= ras.min_ey;
450
451	if ( ex > ras.max_ex )
452	ex = ras.max_ex;
453
454	ex -= ras.min_ex;
455	if ( ex < 0 )
456	ex = -1;
457
458	/* are we moving to a different cell ? */
459	if ( ex != ras.ex || ey != ras.ey )
460	{
461	/* record the current one if it is valid */
462	if ( !ras.invalid )
463	gray_record_cell( RAS_VAR );
464
465	ras.area = 0;
466	ras.cover = 0;
467	ras.ex = ex;
468	ras.ey = ey;
469	}
470
471	ras.invalid = ( (unsigned int)ey >= (unsigned int)ras.count_ey ||
472	ex >= ras.count_ex );
473	}
474
475
476	/*************************************************************************/
477	/* */
478	/* Start a new contour at a given cell. */
479	/* */
480	static void
481	gray_start_cell( RAS_ARG_ TCoord ex,
482	TCoord ey )
483	{
484	if ( ex > ras.max_ex )
485	ex = (TCoord)( ras.max_ex );
486
487	if ( ex < ras.min_ex )
488	ex = (TCoord)( ras.min_ex - 1 );
489
490	ras.area = 0;
491	ras.cover = 0;
492	ras.ex = ex - ras.min_ex;
493	ras.ey = ey - ras.min_ey;
494	ras.invalid = 0;
495
496	gray_set_cell( RAS_VAR_ ex, ey );
497	}
498
499	// The new render-line implementation is not yet used
500	#if 1
501
502	/*************************************************************************/
503	/* */
504	/* Render a scanline as one or more cells. */
505	/* */
506	static void
507	gray_render_scanline( RAS_ARG_ TCoord ey,
508	TPos x1,
509	TCoord y1,
510	TPos x2,
511	TCoord y2 )
512	{
513	TCoord ex1, ex2, fx1, fx2, first, dy, delta, mod;
514	TPos p, dx;
515	int incr;
516
517
518	ex1 = TRUNC( x1 );
519	ex2 = TRUNC( x2 );
520
521	/* trivial case. Happens often */
522	if ( y1 == y2 )
523	{
524	gray_set_cell( RAS_VAR_ ex: ex2, ey );
525	return;
526	}
527
528	fx1 = FRACT( x1 );
529	fx2 = FRACT( x2 );
530
531	/* everything is located in a single cell. That is easy! */
532	/* */
533	if ( ex1 == ex2 )
534	goto End;
535
536	/* ok, we'll have to render a run of adjacent cells on the same */
537	/* scanline... */
538	/* */
539	dx = x2 - x1;
540	dy = y2 - y1;
541
542	if ( dx > 0 )
543	{
544	p = ( ONE_PIXEL - fx1 ) * dy;
545	first = ONE_PIXEL;
546	incr = 1;
547	} else {
548	p = fx1 * dy;
549	first = 0;
550	incr = -1;
551	dx = -dx;
552	}
553
554	QT_FT_DIV_MOD( TCoord, p, dx, delta, mod );
555
556	ras.area += (TArea)( fx1 + first ) * delta;
557	ras.cover += delta;
558	y1 += delta;
559	ex1 += incr;
560	gray_set_cell( RAS_VAR_ ex: ex1, ey );
561
562	if ( ex1 != ex2 )
563	{
564	TCoord lift, rem;
565
566
567	p = ONE_PIXEL * dy;
568	QT_FT_DIV_MOD( TCoord, p, dx, lift, rem );
569
570	do
571	{
572	delta = lift;
573	mod += rem;
574	if ( mod >= (TCoord)dx )
575	{
576	mod -= (TCoord)dx;
577	delta++;
578	}
579
580	ras.area += (TArea)( ONE_PIXEL * delta );
581	ras.cover += delta;
582	y1 += delta;
583	ex1 += incr;
584	gray_set_cell( RAS_VAR_ ex: ex1, ey );
585	} while ( ex1 != ex2 );
586	}
587	fx1 = ONE_PIXEL - first;
588
589	End:
590	dy = y2 - y1;
591
592	ras.area += (TArea)( ( fx1 + fx2 ) * dy );
593	ras.cover += dy;
594	}
595
596
597	/*************************************************************************/
598	/* */
599	/* Render a given line as a series of scanlines. */
600	/* */
601	static void
602	gray_render_line( RAS_ARG_ TPos to_x,
603	TPos to_y )
604	{
605	TCoord ey1, ey2, fy1, fy2, first, delta, mod;
606	TPos p, dx, dy, x, x2;
607	int incr;
608
609	ey1 = TRUNC( ras.y );
610	ey2 = TRUNC( to_y ); /* if (ey2 >= ras.max_ey) ey2 = ras.max_ey-1; */
611
612	/* perform vertical clipping */
613	if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) ||
614	( ey1 < ras.min_ey && ey2 < ras.min_ey ) )
615	goto End;
616
617	fy1 = FRACT( ras.y );
618	fy2 = FRACT( to_y );
619
620	/* everything is on a single scanline */
621	if ( ey1 == ey2 )
622	{
623	gray_render_scanline( RAS_VAR_ ey: ey1, ras.x, y1: fy1, x2: to_x, y2: fy2 );
624	goto End;
625	}
626
627	dx = to_x - ras.x;
628	dy = to_y - ras.y;
629
630	/* vertical line - avoid calling gray_render_scanline */
631	if ( dx == 0 )
632	{
633	TCoord ex = TRUNC( ras.x );
634	TCoord two_fx = FRACT( ras.x ) << 1;
635	TPos area, max_ey1;
636
637
638	if ( dy > 0)
639	{
640	first = ONE_PIXEL;
641	}
642	else
643	{
644	first = 0;
645	}
646
647	delta = first - fy1;
648	ras.area += (TArea)two_fx * delta;
649	ras.cover += delta;
650
651	delta = first + first - ONE_PIXEL;
652	area = (TArea)two_fx * delta;
653	max_ey1 = ras.count_ey + ras.min_ey;
654	if (dy < 0) {
655	if (ey1 > max_ey1) {
656	ey1 = (max_ey1 > ey2) ? max_ey1 : ey2;
657	gray_set_cell( worker: &ras, ex, ey: ey1 );
658	} else {
659	ey1--;
660	gray_set_cell( worker: &ras, ex, ey: ey1 );
661	}
662	while ( ey1 > ey2 && ey1 >= ras.min_ey)
663	{
664	ras.area += area;
665	ras.cover += delta;
666	ey1--;
667
668	gray_set_cell( worker: &ras, ex, ey: ey1 );
669	}
670	if (ey1 != ey2) {
671	ey1 = ey2;
672	gray_set_cell( worker: &ras, ex, ey: ey1 );
673	}
674	} else {
675	if (ey1 < ras.min_ey) {
676	ey1 = (ras.min_ey < ey2) ? ras.min_ey : ey2;
677	gray_set_cell( worker: &ras, ex, ey: ey1 );
678	} else {
679	ey1++;
680	gray_set_cell( worker: &ras, ex, ey: ey1 );
681	}
682	while ( ey1 < ey2 && ey1 < max_ey1)
683	{
684	ras.area += area;
685	ras.cover += delta;
686	ey1++;
687
688	gray_set_cell( worker: &ras, ex, ey: ey1 );
689	}
690	if (ey1 != ey2) {
691	ey1 = ey2;
692	gray_set_cell( worker: &ras, ex, ey: ey1 );
693	}
694	}
695
696	delta = (int)( fy2 - ONE_PIXEL + first );
697	ras.area += (TArea)two_fx * delta;
698	ras.cover += delta;
699
700	goto End;
701	}
702
703	/* ok, we have to render several scanlines */
704	if ( dy > 0)
705	{
706	p = ( ONE_PIXEL - fy1 ) * dx;
707	first = ONE_PIXEL;
708	incr = 1;
709	}
710	else
711	{
712	p = fy1 * dx;
713	first = 0;
714	incr = -1;
715	dy = -dy;
716	}
717
718	/* the fractional part of x-delta is mod/dy. It is essential to */
719	/* keep track of its accumulation for accurate rendering. */
720	QT_FT_DIV_MOD( TCoord, p, dy, delta, mod );
721
722	x = ras.x + delta;
723	gray_render_scanline( RAS_VAR_ ey: ey1, ras.x, y1: fy1, x2: x, y2: (TCoord)first );
724
725	ey1 += incr;
726	gray_set_cell( RAS_VAR_ TRUNC( x ), ey: ey1 );
727
728	if ( ey1 != ey2 )
729	{
730	TCoord lift, rem;
731
732
733	p = ONE_PIXEL * dx;
734	QT_FT_DIV_MOD( TCoord, p, dy, lift, rem );
735
736	do
737	{
738	delta = lift;
739	mod += rem;
740	if ( mod >= (TCoord)dy )
741	{
742	mod -= (TCoord)dy;
743	delta++;
744	}
745
746	x2 = x + delta;
747	gray_render_scanline( RAS_VAR_ ey: ey1,
748	x1: x, ONE_PIXEL - first,
749	x2, y2: first );
750	x = x2;
751
752	ey1 += incr;
753	gray_set_cell( RAS_VAR_ TRUNC( x ), ey: ey1 );
754	} while ( ey1 != ey2 );
755	}
756
757	gray_render_scanline( RAS_VAR_ ey: ey1,
758	x1: x, ONE_PIXEL - first,
759	x2: to_x, y2: fy2 );
760
761	End:
762	ras.x = to_x;
763	ras.y = to_y;
764	}
765
766
767	#else
768
769	/*************************************************************************/
770	/* */
771	/* Render a straight line across multiple cells in any direction. */
772	/* */
773	static void
774	gray_render_line( RAS_ARG_ TPos to_x,
775	TPos to_y )
776	{
777	TPos dx, dy, fx1, fy1, fx2, fy2;
778	TCoord ex1, ex2, ey1, ey2;
779
780
781	ex1 = TRUNC( ras.x );
782	ex2 = TRUNC( to_x );
783	ey1 = TRUNC( ras.y );
784	ey2 = TRUNC( to_y );
785
786	/* perform vertical clipping */
787	if ( ( ey1 >= ras.max_ey && ey2 >= ras.max_ey ) ||
788	( ey1 < ras.min_ey && ey2 < ras.min_ey ) )
789	goto End;
790
791	dx = to_x - ras.x;
792	dy = to_y - ras.y;
793
794	fx1 = FRACT( ras.x );
795	fy1 = FRACT( ras.y );
796
797	if ( ex1 == ex2 && ey1 == ey2 ) /* inside one cell */
798	;
799	else if ( dy == 0 ) /* ex1 != ex2 */ /* any horizontal line */
800	{
801	ex1 = ex2;
802	gray_set_cell( RAS_VAR_ ex1, ey1 );
803	}
804	else if ( dx == 0 )
805	{
806	if ( dy > 0 ) /* vertical line up */
807	do
808	{
809	fy2 = ONE_PIXEL;
810	ras.cover += ( fy2 - fy1 );
811	ras.area += ( fy2 - fy1 ) * fx1 * 2;
812	fy1 = 0;
813	ey1++;
814	gray_set_cell( RAS_VAR_ ex1, ey1 );
815	} while ( ey1 != ey2 );
816	else /* vertical line down */
817	do
818	{
819	fy2 = 0;
820	ras.cover += ( fy2 - fy1 );
821	ras.area += ( fy2 - fy1 ) * fx1 * 2;
822	fy1 = ONE_PIXEL;
823	ey1--;
824	gray_set_cell( RAS_VAR_ ex1, ey1 );
825	} while ( ey1 != ey2 );
826	}
827	else /* any other line */
828	{
829	TArea prod = dx * fy1 - dy * fx1;
830	QT_FT_UDIVPREP( dx );
831	QT_FT_UDIVPREP( dy );
832
833
834	/* The fundamental value `prod' determines which side and the */
835	/* exact coordinate where the line exits current cell. It is */
836	/* also easily updated when moving from one cell to the next. */
837	do
838	{
839	if ( prod <= 0 &&
840	prod - dx * ONE_PIXEL > 0 ) /* left */
841	{
842	fx2 = 0;
843	fy2 = (TPos)QT_FT_UDIV( -prod, -dx );
844	prod -= dy * ONE_PIXEL;
845	ras.cover += ( fy2 - fy1 );
846	ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
847	fx1 = ONE_PIXEL;
848	fy1 = fy2;
849	ex1--;
850	}
851	else if ( prod - dx * ONE_PIXEL <= 0 &&
852	prod - dx * ONE_PIXEL + dy * ONE_PIXEL > 0 ) /* up */
853	{
854	prod -= dx * ONE_PIXEL;
855	fx2 = (TPos)QT_FT_UDIV( -prod, dy );
856	fy2 = ONE_PIXEL;
857	ras.cover += ( fy2 - fy1 );
858	ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
859	fx1 = fx2;
860	fy1 = 0;
861	ey1++;
862	}
863	else if ( prod - dx * ONE_PIXEL + dy * ONE_PIXEL <= 0 &&
864	prod + dy * ONE_PIXEL >= 0 ) /* right */
865	{
866	prod += dy * ONE_PIXEL;
867	fx2 = ONE_PIXEL;
868	fy2 = (TPos)QT_FT_UDIV( prod, dx );
869	ras.cover += ( fy2 - fy1 );
870	ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
871	fx1 = 0;
872	fy1 = fy2;
873	ex1++;
874	}
875	else /* ( prod + dy * ONE_PIXEL < 0 &&
876	prod > 0 ) down */
877	{
878	fx2 = (TPos)QT_FT_UDIV( prod, -dy );
879	fy2 = 0;
880	prod += dx * ONE_PIXEL;
881	ras.cover += ( fy2 - fy1 );
882	ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
883	fx1 = fx2;
884	fy1 = ONE_PIXEL;
885	ey1--;
886	}
887
888	gray_set_cell( RAS_VAR_ ex1, ey1 );
889	} while ( ex1 != ex2 || ey1 != ey2 );
890	}
891
892	fx2 = FRACT( to_x );
893	fy2 = FRACT( to_y );
894
895	ras.cover += ( fy2 - fy1 );
896	ras.area += ( fy2 - fy1 ) * ( fx1 + fx2 );
897
898	End:
899	ras.x = to_x;
900	ras.y = to_y;
901	}
902
903	#endif
904
905	static void
906	gray_split_conic( QT_FT_Vector* base )
907	{
908	TPos a, b;
909
910
911	base[4].x = base[2].x;
912	b = base[1].x;
913	a = base[3].x = ( base[2].x + b ) / 2;
914	b = base[1].x = ( base[0].x + b ) / 2;
915	base[2].x = ( a + b ) / 2;
916
917	base[4].y = base[2].y;
918	b = base[1].y;
919	a = base[3].y = ( base[2].y + b ) / 2;
920	b = base[1].y = ( base[0].y + b ) / 2;
921	base[2].y = ( a + b ) / 2;
922	}
923
924
925	static void
926	gray_render_conic( RAS_ARG_ const QT_FT_Vector* control,
927	const QT_FT_Vector* to )
928	{
929	QT_FT_Vector bez_stack[16 * 2 + 1]; /* enough to accommodate bisections */
930	QT_FT_Vector* arc = bez_stack;
931	TPos dx, dy;
932	int draw, split;
933
934
935	arc[0].x = UPSCALE( to->x );
936	arc[0].y = UPSCALE( to->y );
937	arc[1].x = UPSCALE( control->x );
938	arc[1].y = UPSCALE( control->y );
939	arc[2].x = ras.x;
940	arc[2].y = ras.y;
941
942	/* short-cut the arc that crosses the current band */
943	if ( ( TRUNC( arc[0].y ) >= ras.max_ey &&
944	TRUNC( arc[1].y ) >= ras.max_ey &&
945	TRUNC( arc[2].y ) >= ras.max_ey ) ||
946	( TRUNC( arc[0].y ) < ras.min_ey &&
947	TRUNC( arc[1].y ) < ras.min_ey &&
948	TRUNC( arc[2].y ) < ras.min_ey ) )
949	{
950	ras.x = arc[0].x;
951	ras.y = arc[0].y;
952	return;
953	}
954
955	dx = QT_FT_ABS( arc[2].x + arc[0].x - 2 * arc[1].x );
956	dy = QT_FT_ABS( arc[2].y + arc[0].y - 2 * arc[1].y );
957	if ( dx < dy )
958	dx = dy;
959
960	/* We can calculate the number of necessary bisections because */
961	/* each bisection predictably reduces deviation exactly 4-fold. */
962	/* Even 32-bit deviation would vanish after 16 bisections. */
963	draw = 1;
964	while ( dx > ONE_PIXEL / 4 )
965	{
966	dx >>= 2;
967	draw <<= 1;
968	}
969
970	/* We use decrement counter to count the total number of segments */
971	/* to draw starting from 2^level. Before each draw we split as */
972	/* many times as there are trailing zeros in the counter. */
973	do
974	{
975	split = 1;
976	while ( ( draw & split ) == 0 )
977	{
978	gray_split_conic( base: arc );
979	arc += 2;
980	split <<= 1;
981	}
982
983	gray_render_line( RAS_VAR_ to_x: arc[0].x, to_y: arc[0].y );
984	arc -= 2;
985
986	} while ( --draw );
987	}
988
989
990	static void
991	gray_split_cubic( QT_FT_Vector* base )
992	{
993	TPos a, b, c, d;
994
995
996	base[6].x = base[3].x;
997	c = base[1].x;
998	d = base[2].x;
999	base[1].x = a = ( base[0].x + c ) / 2;
1000	base[5].x = b = ( base[3].x + d ) / 2;
1001	c = ( c + d ) / 2;
1002	base[2].x = a = ( a + c ) / 2;
1003	base[4].x = b = ( b + c ) / 2;
1004	base[3].x = ( a + b ) / 2;
1005
1006	base[6].y = base[3].y;
1007	c = base[1].y;
1008	d = base[2].y;
1009	base[1].y = a = ( base[0].y + c ) / 2;
1010	base[5].y = b = ( base[3].y + d ) / 2;
1011	c = ( c + d ) / 2;
1012	base[2].y = a = ( a + c ) / 2;
1013	base[4].y = b = ( b + c ) / 2;
1014	base[3].y = ( a + b ) / 2;
1015	}
1016
1017
1018	static void
1019	gray_render_cubic( RAS_ARG_ const QT_FT_Vector* control1,
1020	const QT_FT_Vector* control2,
1021	const QT_FT_Vector* to )
1022	{
1023	QT_FT_Vector bez_stack[16 * 3 + 1]; /* enough to accommodate bisections */
1024	QT_FT_Vector* arc = bez_stack;
1025	TPos dx, dy, dx_, dy_;
1026	TPos dx1, dy1, dx2, dy2;
1027	TPos L, s, s_limit;
1028
1029
1030	arc[0].x = UPSCALE( to->x );
1031	arc[0].y = UPSCALE( to->y );
1032	arc[1].x = UPSCALE( control2->x );
1033	arc[1].y = UPSCALE( control2->y );
1034	arc[2].x = UPSCALE( control1->x );
1035	arc[2].y = UPSCALE( control1->y );
1036	arc[3].x = ras.x;
1037	arc[3].y = ras.y;
1038
1039	/* short-cut the arc that crosses the current band */
1040	if ( ( TRUNC( arc[0].y ) >= ras.max_ey &&
1041	TRUNC( arc[1].y ) >= ras.max_ey &&
1042	TRUNC( arc[2].y ) >= ras.max_ey &&
1043	TRUNC( arc[3].y ) >= ras.max_ey ) ||
1044	( TRUNC( arc[0].y ) < ras.min_ey &&
1045	TRUNC( arc[1].y ) < ras.min_ey &&
1046	TRUNC( arc[2].y ) < ras.min_ey &&
1047	TRUNC( arc[3].y ) < ras.min_ey ) )
1048	{
1049	ras.x = arc[0].x;
1050	ras.y = arc[0].y;
1051	return;
1052	}
1053
1054	for (;;)
1055	{
1056	/* Decide whether to split or draw. See `Rapid Termination */
1057	/* Evaluation for Recursive Subdivision of Bezier Curves' by Thomas */
1058	/* F. Hain, at */
1059	/* http://www.cis.southalabama.edu/~hain/general/Publications/Bezier/Camera-ready%20CISST02%202.pdf */
1060
1061
1062	/* dx and dy are x and y components of the P0-P3 chord vector. */
1063	dx = dx_ = arc[3].x - arc[0].x;
1064	dy = dy_ = arc[3].y - arc[0].y;
1065
1066	L = QT_FT_HYPOT( dx_, dy_ );
1067
1068	/* Avoid possible arithmetic overflow below by splitting. */
1069	if ( L >= (1 << 23) )
1070	goto Split;
1071
1072	/* Max deviation may be as much as (s/L) * 3/4 (if Hain's v = 1). */
1073	s_limit = L * (TPos)( ONE_PIXEL / 6 );
1074
1075	/* s is L * the perpendicular distance from P1 to the line P0-P3. */
1076	dx1 = arc[1].x - arc[0].x;
1077	dy1 = arc[1].y - arc[0].y;
1078	s = QT_FT_ABS( dy * dx1 - dx * dy1 );
1079
1080	if ( s > s_limit )
1081	goto Split;
1082
1083	/* s is L * the perpendicular distance from P2 to the line P0-P3. */
1084	dx2 = arc[2].x - arc[0].x;
1085	dy2 = arc[2].y - arc[0].y;
1086	s = QT_FT_ABS( dy * dx2 - dx * dy2 );
1087
1088	if ( s > s_limit )
1089	goto Split;
1090
1091	/* Split super curvy segments where the off points are so far
1092	from the chord that the angles P0-P1-P3 or P0-P2-P3 become
1093	acute as detected by appropriate dot products. */
1094	if ( dx1 * ( dx1 - dx ) + dy1 * ( dy1 - dy ) > 0 ||
1095	dx2 * ( dx2 - dx ) + dy2 * ( dy2 - dy ) > 0 )
1096	goto Split;
1097
1098	gray_render_line( RAS_VAR_ to_x: arc[0].x, to_y: arc[0].y );
1099
1100	if ( arc == bez_stack )
1101	return;
1102
1103	arc -= 3;
1104	continue;
1105
1106	Split:
1107	gray_split_cubic( base: arc );
1108	arc += 3;
1109	}
1110	}
1111
1112
1113
1114	static int
1115	gray_move_to( const QT_FT_Vector* to,
1116	PWorker worker )
1117	{
1118	TPos x, y;
1119
1120
1121	/* record current cell, if any */
1122	if ( !ras.invalid )
1123	gray_record_cell( worker );
1124
1125	/* start to a new position */
1126	x = UPSCALE( to->x );
1127	y = UPSCALE( to->y );
1128
1129	gray_start_cell( worker, TRUNC( x ), TRUNC( y ) );
1130
1131	ras.x = x;
1132	ras.y = y;
1133	return 0;
1134	}
1135
1136	static void
1137	gray_render_span( int count,
1138	const QT_FT_Span* spans,
1139	PWorker worker )
1140	{
1141	unsigned char* p;
1142	QT_FT_Bitmap* map = &worker->target;
1143
1144	for ( ; count > 0; count--, spans++ )
1145	{
1146	unsigned char coverage = spans->coverage;
1147
1148	/* first of all, compute the scanline offset */
1149	p = (unsigned char*)map->buffer - spans->y * map->pitch;
1150	if ( map->pitch >= 0 )
1151	p += ( map->rows - 1 ) * (unsigned int)map->pitch;
1152
1153
1154	if ( coverage )
1155	{
1156	unsigned char* q = p + spans->x;
1157
1158
1159	/* For small-spans it is faster to do it by ourselves than
1160	* calling `memset'. This is mainly due to the cost of the
1161	* function call.
1162	*/
1163	switch ( spans->len )
1164	{
1165	case 7: *q++ = coverage; Q_FALLTHROUGH();
1166	case 6: *q++ = coverage; Q_FALLTHROUGH();
1167	case 5: *q++ = coverage; Q_FALLTHROUGH();
1168	case 4: *q++ = coverage; Q_FALLTHROUGH();
1169	case 3: *q++ = coverage; Q_FALLTHROUGH();
1170	case 2: *q++ = coverage; Q_FALLTHROUGH();
1171	case 1: *q = coverage; Q_FALLTHROUGH();
1172	case 0: break;
1173	default:
1174	QT_FT_MEM_SET( q, coverage, spans->len );
1175	}
1176	}
1177	}
1178	}
1179
1180
1181	static void
1182	gray_hline( RAS_ARG_ TCoord x,
1183	TCoord y,
1184	TPos area,
1185	int acount )
1186	{
1187	int coverage;
1188
1189
1190	/* compute the coverage line's coverage, depending on the */
1191	/* outline fill rule */
1192	/* */
1193	/* the coverage percentage is area/(PIXEL_BITS*PIXEL_BITS*2) */
1194	/* */
1195	coverage = (int)( area >> ( PIXEL_BITS * 2 + 1 - 8 ) );
1196	/* use range 0..256 */
1197	if ( coverage < 0 )
1198	coverage = -coverage;
1199
1200	if ( ras.outline.flags & QT_FT_OUTLINE_EVEN_ODD_FILL )
1201	{
1202	coverage &= 511;
1203
1204	if ( coverage > 256 )
1205	coverage = 512 - coverage;
1206	else if ( coverage == 256 )
1207	coverage = 255;
1208	}
1209	else
1210	{
1211	/* normal non-zero winding rule */
1212	if ( coverage >= 256 )
1213	coverage = 255;
1214	}
1215
1216	y += (TCoord)ras.min_ey;
1217	x += (TCoord)ras.min_ex;
1218
1219	/* QT_FT_Span.x is an int, so limit our coordinates appropriately */
1220	if ( x >= (1 << 23) )
1221	x = (1 << 23) - 1;
1222
1223	/* QT_FT_Span.y is an int, so limit our coordinates appropriately */
1224	if ( y >= (1 << 23) )
1225	y = (1 << 23) - 1;
1226
1227	if ( coverage )
1228	{
1229	QT_FT_Span* span;
1230	int count;
1231	int skip;
1232
1233
1234	/* see whether we can add this span to the current list */
1235	count = ras.num_gray_spans;
1236	span = ras.gray_spans + count - 1;
1237	if ( count > 0 &&
1238	span->y == y &&
1239	span->x + span->len == x &&
1240	span->coverage == coverage )
1241	{
1242	span->len = span->len + acount;
1243	return;
1244	}
1245
1246	if ( count >= QT_FT_MAX_GRAY_SPANS )
1247	{
1248	if ( ras.render_span && count > ras.skip_spans )
1249	{
1250	skip = ras.skip_spans > 0 ? ras.skip_spans : 0;
1251	ras.render_span( ras.num_gray_spans - skip,
1252	ras.gray_spans + skip,
1253	ras.render_span_data );
1254	}
1255
1256	ras.skip_spans -= ras.num_gray_spans;
1257
1258	/* ras.render_span( span->y, ras.gray_spans, count ); */
1259
1260	#ifdef DEBUG_GRAYS
1261
1262	if ( 1 )
1263	{
1264	int n;
1265
1266
1267	fprintf( stderr, "y=%3d ", y );
1268	span = ras.gray_spans;
1269	for ( n = 0; n < count; n++, span++ )
1270	fprintf( stderr, "[%d..%d]:%02x ",
1271	span->x, span->x + span->len - 1, span->coverage );
1272	fprintf( stderr, "\n" );
1273	}
1274
1275	#endif /* DEBUG_GRAYS */
1276
1277	ras.num_gray_spans = 0;
1278
1279	span = ras.gray_spans;
1280	}
1281	else
1282	span++;
1283
1284	/* add a gray span to the current list */
1285	span->x = x;
1286	span->len = acount;
1287	span->y = y;
1288	span->coverage = (unsigned char)coverage;
1289
1290	ras.num_gray_spans++;
1291	}
1292	}
1293
1294
1295	#ifdef DEBUG_GRAYS
1296
1297	/* to be called while in the debugger */
1298	gray_dump_cells( RAS_ARG )
1299	{
1300	int yindex;
1301
1302
1303	for ( yindex = 0; yindex < ras.ycount; yindex++ )
1304	{
1305	PCell cell;
1306
1307
1308	printf( "%3d:", yindex );
1309
1310	for ( cell = ras.ycells[yindex]; cell != NULL; cell = cell->next )
1311	printf( " (%3d, c:%4d, a:%6d)", cell->x, cell->cover, cell->area );
1312	printf( "\n" );
1313	}
1314	}
1315
1316	#endif /* DEBUG_GRAYS */
1317
1318
1319	static void
1320	gray_sweep( RAS_ARG_ const QT_FT_Bitmap* target )
1321	{
1322	int yindex;
1323
1324	QT_FT_UNUSED( target );
1325
1326
1327	if ( ras.num_cells == 0 )
1328	return;
1329
1330	QT_FT_TRACE7(( "gray_sweep: start\n" ));
1331
1332	for ( yindex = 0; yindex < ras.ycount; yindex++ )
1333	{
1334	PCell cell = ras.ycells[yindex];
1335	TCoord cover = 0;
1336	TCoord x = 0;
1337
1338
1339	for ( ; cell != NULL; cell = cell->next )
1340	{
1341	TArea area;
1342
1343
1344	if ( cell->x > x && cover != 0 )
1345	gray_hline( RAS_VAR_ x, y: yindex, area: cover * ( ONE_PIXEL * 2 ),
1346	acount: cell->x - x );
1347
1348	cover += cell->cover;
1349	area = cover * ( ONE_PIXEL * 2 ) - cell->area;
1350
1351	if ( area != 0 && cell->x >= 0 )
1352	gray_hline( RAS_VAR_ x: cell->x, y: yindex, area, acount: 1 );
1353
1354	x = cell->x + 1;
1355	}
1356
1357	if ( ras.count_ex > x && cover != 0 )
1358	gray_hline( RAS_VAR_ x, y: yindex, area: cover * ( ONE_PIXEL * 2 ),
1359	ras.count_ex - x );
1360	}
1361
1362	QT_FT_TRACE7(( "gray_sweep: end\n" ));
1363	}
1364
1365	/*************************************************************************/
1366	/* */
1367	/* The following function should only compile in stand_alone mode, */
1368	/* i.e., when building this component without the rest of FreeType. */
1369	/* */
1370	/*************************************************************************/
1371
1372	/*************************************************************************/
1373	/* */
1374	/* <Function> */
1375	/* QT_FT_Outline_Decompose */
1376	/* */
1377	/* <Description> */
1378	/* Walks over an outline's structure to decompose it into individual */
1379	/* segments and Bezier arcs. This function is also able to emit */
1380	/* `move to' and `close to' operations to indicate the start and end */
1381	/* of new contours in the outline. */
1382	/* */
1383	/* <Input> */
1384	/* outline :: A pointer to the source target. */
1385	/* */
1386	/* user :: A typeless pointer which is passed to each */
1387	/* emitter during the decomposition. It can be */
1388	/* used to store the state during the */
1389	/* decomposition. */
1390	/* */
1391	/* <Return> */
1392	/* Error code. 0 means success. */
1393	/* */
1394	static
1395	int QT_FT_Outline_Decompose( const QT_FT_Outline* outline,
1396	void* user )
1397	{
1398	#undef SCALED
1399	#define SCALED( x ) (x)
1400
1401	QT_FT_Vector v_last;
1402	QT_FT_Vector v_control;
1403	QT_FT_Vector v_start;
1404
1405	QT_FT_Vector* point;
1406	QT_FT_Vector* limit;
1407	char* tags;
1408
1409	int n; /* index of contour in outline */
1410	int first; /* index of first point in contour */
1411	int error;
1412	char tag; /* current point's state */
1413
1414	if ( !outline )
1415	return ErrRaster_Invalid_Outline;
1416
1417	first = 0;
1418
1419	for ( n = 0; n < outline->n_contours; n++ )
1420	{
1421	int last; /* index of last point in contour */
1422
1423
1424	last = outline->contours[n];
1425	if ( last < 0 )
1426	goto Invalid_Outline;
1427	limit = outline->points + last;
1428
1429	v_start = outline->points[first];
1430	v_start.x = SCALED( v_start.x );
1431	v_start.y = SCALED( v_start.y );
1432
1433	v_last = outline->points[last];
1434	v_last.x = SCALED( v_last.x );
1435	v_last.y = SCALED( v_last.y );
1436
1437	v_control = v_start;
1438
1439	point = outline->points + first;
1440	tags = outline->tags + first;
1441	tag = QT_FT_CURVE_TAG( tags[0] );
1442
1443	/* A contour cannot start with a cubic control point! */
1444	if ( tag == QT_FT_CURVE_TAG_CUBIC )
1445	goto Invalid_Outline;
1446
1447	/* check first point to determine origin */
1448	if ( tag == QT_FT_CURVE_TAG_CONIC )
1449	{
1450	/* first point is conic control. Yes, this happens. */
1451	if ( QT_FT_CURVE_TAG( outline->tags[last] ) == QT_FT_CURVE_TAG_ON )
1452	{
1453	/* start at last point if it is on the curve */
1454	v_start = v_last;
1455	limit--;
1456	}
1457	else
1458	{
1459	/* if both first and last points are conic, */
1460	/* start at their middle and record its position */
1461	/* for closure */
1462	v_start.x = ( v_start.x + v_last.x ) / 2;
1463	v_start.y = ( v_start.y + v_last.y ) / 2;
1464
1465	v_last = v_start;
1466	}
1467	point--;
1468	tags--;
1469	}
1470
1471	QT_FT_TRACE5(( " move to (%.2f, %.2f)\n",
1472	v_start.x / 64.0, v_start.y / 64.0 ));
1473	error = gray_move_to( to: &v_start, worker: user );
1474	if ( error )
1475	goto Exit;
1476
1477	while ( point < limit )
1478	{
1479	point++;
1480	tags++;
1481
1482	tag = QT_FT_CURVE_TAG( tags[0] );
1483	switch ( tag )
1484	{
1485	case QT_FT_CURVE_TAG_ON: /* emit a single line_to */
1486	{
1487	QT_FT_Vector vec;
1488
1489
1490	vec.x = SCALED( point->x );
1491	vec.y = SCALED( point->y );
1492
1493	QT_FT_TRACE5(( " line to (%.2f, %.2f)\n",
1494	vec.x / 64.0, vec.y / 64.0 ));
1495	gray_render_line(worker: user, UPSCALE(vec.x), UPSCALE(vec.y));
1496	continue;
1497	}
1498
1499	case QT_FT_CURVE_TAG_CONIC: /* consume conic arcs */
1500	{
1501	v_control.x = SCALED( point->x );
1502	v_control.y = SCALED( point->y );
1503
1504	Do_Conic:
1505	if ( point < limit )
1506	{
1507	QT_FT_Vector vec;
1508	QT_FT_Vector v_middle;
1509
1510
1511	point++;
1512	tags++;
1513	tag = QT_FT_CURVE_TAG( tags[0] );
1514
1515	vec.x = SCALED( point->x );
1516	vec.y = SCALED( point->y );
1517
1518	if ( tag == QT_FT_CURVE_TAG_ON )
1519	{
1520	QT_FT_TRACE5(( " conic to (%.2f, %.2f)"
1521	" with control (%.2f, %.2f)\n",
1522	vec.x / 64.0, vec.y / 64.0,
1523	v_control.x / 64.0, v_control.y / 64.0 ));
1524	gray_render_conic(worker: user, control: &v_control, to: &vec);
1525	continue;
1526	}
1527
1528	if ( tag != QT_FT_CURVE_TAG_CONIC )
1529	goto Invalid_Outline;
1530
1531	v_middle.x = ( v_control.x + vec.x ) / 2;
1532	v_middle.y = ( v_control.y + vec.y ) / 2;
1533
1534	QT_FT_TRACE5(( " conic to (%.2f, %.2f)"
1535	" with control (%.2f, %.2f)\n",
1536	v_middle.x / 64.0, v_middle.y / 64.0,
1537	v_control.x / 64.0, v_control.y / 64.0 ));
1538	gray_render_conic(worker: user, control: &v_control, to: &v_middle);
1539
1540	v_control = vec;
1541	goto Do_Conic;
1542	}
1543
1544	QT_FT_TRACE5(( " conic to (%.2f, %.2f)"
1545	" with control (%.2f, %.2f)\n",
1546	v_start.x / 64.0, v_start.y / 64.0,
1547	v_control.x / 64.0, v_control.y / 64.0 ));
1548	gray_render_conic(worker: user, control: &v_control, to: &v_start);
1549	goto Close;
1550	}
1551
1552	default: /* QT_FT_CURVE_TAG_CUBIC */
1553	{
1554	QT_FT_Vector vec1, vec2;
1555
1556
1557	if ( point + 1 > limit ||
1558	QT_FT_CURVE_TAG( tags[1] ) != QT_FT_CURVE_TAG_CUBIC )
1559	goto Invalid_Outline;
1560
1561	point += 2;
1562	tags += 2;
1563
1564	vec1.x = SCALED( point[-2].x );
1565	vec1.y = SCALED( point[-2].y );
1566
1567	vec2.x = SCALED( point[-1].x );
1568	vec2.y = SCALED( point[-1].y );
1569
1570	if ( point <= limit )
1571	{
1572	QT_FT_Vector vec;
1573
1574
1575	vec.x = SCALED( point->x );
1576	vec.y = SCALED( point->y );
1577
1578	QT_FT_TRACE5(( " cubic to (%.2f, %.2f)"
1579	" with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
1580	vec.x / 64.0, vec.y / 64.0,
1581	vec1.x / 64.0, vec1.y / 64.0,
1582	vec2.x / 64.0, vec2.y / 64.0 ));
1583	gray_render_cubic(worker: user, control1: &vec1, control2: &vec2, to: &vec);
1584	continue;
1585	}
1586
1587	QT_FT_TRACE5(( " cubic to (%.2f, %.2f)"
1588	" with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
1589	v_start.x / 64.0, v_start.y / 64.0,
1590	vec1.x / 64.0, vec1.y / 64.0,
1591	vec2.x / 64.0, vec2.y / 64.0 ));
1592	gray_render_cubic(worker: user, control1: &vec1, control2: &vec2, to: &v_start);
1593	goto Close;
1594	}
1595	}
1596	}
1597
1598	/* close the contour with a line segment */
1599	QT_FT_TRACE5(( " line to (%.2f, %.2f)\n",
1600	v_start.x / 64.0, v_start.y / 64.0 ));
1601	gray_render_line(worker: user, UPSCALE(v_start.x), UPSCALE(v_start.y));
1602
1603	Close:
1604	first = last + 1;
1605	}
1606
1607	QT_FT_TRACE5(( "FT_Outline_Decompose: Done\n", n ));
1608	return 0;
1609
1610	Exit:
1611	QT_FT_TRACE5(( "FT_Outline_Decompose: Error %d\n", error ));
1612	return error;
1613
1614	Invalid_Outline:
1615	return ErrRaster_Invalid_Outline;
1616	}
1617
1618	typedef struct TBand_
1619	{
1620	TPos min, max;
1621
1622	} TBand;
1623
1624	static int
1625	gray_convert_glyph_inner( RAS_ARG )
1626	{
1627	volatile int error = 0;
1628
1629	if ( qt_ft_setjmp( ras.jump_buffer ) == 0 )
1630	{
1631	error = QT_FT_Outline_Decompose( outline: &ras.outline, user: &ras );
1632	if ( !ras.invalid )
1633	gray_record_cell( RAS_VAR );
1634	}
1635	else
1636	{
1637	error = ErrRaster_Memory_Overflow;
1638	}
1639
1640	return error;
1641	}
1642
1643
1644	static int
1645	gray_convert_glyph( RAS_ARG )
1646	{
1647	TBand bands[40];
1648	TBand* volatile band;
1649	int volatile n, num_bands;
1650	TPos volatile min, max, max_y;
1651	QT_FT_BBox* clip;
1652	int skip;
1653
1654	ras.num_gray_spans = 0;
1655
1656	/* Set up state in the raster object */
1657	gray_compute_cbox( RAS_VAR );
1658
1659	/* clip to target bitmap, exit if nothing to do */
1660	clip = &ras.clip_box;
1661
1662	if ( ras.max_ex <= clip->xMin || ras.min_ex >= clip->xMax ||
1663	ras.max_ey <= clip->yMin || ras.min_ey >= clip->yMax )
1664	return 0;
1665
1666	if ( ras.min_ex < clip->xMin ) ras.min_ex = clip->xMin;
1667	if ( ras.min_ey < clip->yMin ) ras.min_ey = clip->yMin;
1668
1669	if ( ras.max_ex > clip->xMax ) ras.max_ex = clip->xMax;
1670	if ( ras.max_ey > clip->yMax ) ras.max_ey = clip->yMax;
1671
1672	ras.count_ex = ras.max_ex - ras.min_ex;
1673	ras.count_ey = ras.max_ey - ras.min_ey;
1674
1675	/* set up vertical bands */
1676	num_bands = (int)( ( ras.max_ey - ras.min_ey ) / ras.band_size );
1677	if ( num_bands == 0 )
1678	num_bands = 1;
1679	if ( num_bands >= 39 )
1680	num_bands = 39;
1681
1682	ras.band_shoot = 0;
1683
1684	min = ras.min_ey;
1685	max_y = ras.max_ey;
1686
1687	for ( n = 0; n < num_bands; n++, min = max )
1688	{
1689	max = min + ras.band_size;
1690	if ( n == num_bands - 1 || max > max_y )
1691	max = max_y;
1692
1693	bands[0].min = min;
1694	bands[0].max = max;
1695	band = bands;
1696
1697	while ( band >= bands )
1698	{
1699	TPos bottom, top, middle;
1700	int error;
1701
1702	{
1703	PCell cells_max;
1704	int yindex;
1705	int cell_start, cell_end, cell_mod;
1706
1707
1708	ras.ycells = (PCell*)ras.buffer;
1709	ras.ycount = band->max - band->min;
1710
1711	cell_start = sizeof ( PCell ) * ras.ycount;
1712	cell_mod = cell_start % sizeof ( TCell );
1713	if ( cell_mod > 0 )
1714	cell_start += sizeof ( TCell ) - cell_mod;
1715
1716	cell_end = ras.buffer_size;
1717	cell_end -= cell_end % sizeof( TCell );
1718
1719	cells_max = (PCell)( (char*)ras.buffer + cell_end );
1720	ras.cells = (PCell)( (char*)ras.buffer + cell_start );
1721	if ( ras.cells >= cells_max )
1722	goto ReduceBands;
1723
1724	ras.max_cells = (int)(cells_max - ras.cells);
1725	if ( ras.max_cells < 2 )
1726	goto ReduceBands;
1727
1728	for ( yindex = 0; yindex < ras.ycount; yindex++ )
1729	ras.ycells[yindex] = NULL;
1730	}
1731
1732	ras.num_cells = 0;
1733	ras.invalid = 1;
1734	ras.min_ey = band->min;
1735	ras.max_ey = band->max;
1736	ras.count_ey = band->max - band->min;
1737
1738	error = gray_convert_glyph_inner( RAS_VAR );
1739
1740	if ( !error )
1741	{
1742	gray_sweep( RAS_VAR_ target: &ras.target );
1743	band--;
1744	continue;
1745	}
1746	else if ( error != ErrRaster_Memory_Overflow )
1747	return 1;
1748
1749	ReduceBands:
1750	/* render pool overflow; we will reduce the render band by half */
1751	bottom = band->min;
1752	top = band->max;
1753	middle = bottom + ( ( top - bottom ) >> 1 );
1754
1755	/* This is too complex for a single scanline; there must */
1756	/* be some problems. */
1757	if ( middle == bottom )
1758	{
1759	#ifdef DEBUG_GRAYS
1760	fprintf( stderr, "Rotten glyph!\n" );
1761	#endif
1762	return ErrRaster_OutOfMemory;
1763	}
1764
1765	if ( bottom-top >= ras.band_size )
1766	ras.band_shoot++;
1767
1768	band[1].min = bottom;
1769	band[1].max = middle;
1770	band[0].min = middle;
1771	band[0].max = top;
1772	band++;
1773	}
1774	}
1775
1776	if ( ras.render_span && ras.num_gray_spans > ras.skip_spans )
1777	{
1778	skip = ras.skip_spans > 0 ? ras.skip_spans : 0;
1779	ras.render_span( ras.num_gray_spans - skip,
1780	ras.gray_spans + skip,
1781	ras.render_span_data );
1782	}
1783
1784	ras.skip_spans -= ras.num_gray_spans;
1785
1786	if ( ras.band_shoot > 8 && ras.band_size > 16 )
1787	ras.band_size = ras.band_size / 2;
1788
1789	return 0;
1790	}
1791
1792
1793	static int
1794	gray_raster_render( QT_FT_Raster raster,
1795	const QT_FT_Raster_Params* params )
1796	{
1797	const QT_FT_Outline* outline = (const QT_FT_Outline*)params->source;
1798	const QT_FT_Bitmap* target_map = params->target;
1799	PWorker worker;
1800
1801
1802	if ( !raster || !raster->buffer || !raster->buffer_size )
1803	return ErrRaster_Invalid_Argument;
1804
1805	/* Should always be non-null, it is set by raster_reset() which is always */
1806	/* called with a non-null pool, and a pool_size >= MINIMUM_POOL_SIZE. */
1807	assert(raster->worker);
1808
1809	raster->worker->skip_spans = params->skip_spans;
1810
1811	/* If raster object and raster buffer are allocated, but */
1812	/* raster size isn't of the minimum size, indicate out of */
1813	/* memory. */
1814	if (raster->buffer_allocated_size < MINIMUM_POOL_SIZE )
1815	return ErrRaster_OutOfMemory;
1816
1817	if ( !outline )
1818	return ErrRaster_Invalid_Outline;
1819
1820	/* return immediately if the outline is empty */
1821	if ( outline->n_points == 0 || outline->n_contours <= 0 )
1822	return 0;
1823
1824	if ( !outline->contours || !outline->points )
1825	return ErrRaster_Invalid_Outline;
1826
1827	if ( outline->n_points !=
1828	outline->contours[outline->n_contours - 1] + 1 )
1829	return ErrRaster_Invalid_Outline;
1830
1831	worker = raster->worker;
1832
1833	/* if direct mode is not set, we must have a target bitmap */
1834	if ( ( params->flags & QT_FT_RASTER_FLAG_DIRECT ) == 0 )
1835	{
1836	if ( !target_map )
1837	return ErrRaster_Invalid_Argument;
1838
1839	/* nothing to do */
1840	if ( !target_map->width || !target_map->rows )
1841	return 0;
1842
1843	if ( !target_map->buffer )
1844	return ErrRaster_Invalid_Argument;
1845	}
1846
1847	/* this version does not support monochrome rendering */
1848	if ( !( params->flags & QT_FT_RASTER_FLAG_AA ) )
1849	return ErrRaster_Invalid_Mode;
1850
1851	/* compute clipping box */
1852	if ( ( params->flags & QT_FT_RASTER_FLAG_DIRECT ) == 0 )
1853	{
1854	/* compute clip box from target pixmap */
1855	ras.clip_box.xMin = 0;
1856	ras.clip_box.yMin = 0;
1857	ras.clip_box.xMax = target_map->width;
1858	ras.clip_box.yMax = target_map->rows;
1859	}
1860	else if ( params->flags & QT_FT_RASTER_FLAG_CLIP )
1861	{
1862	ras.clip_box = params->clip_box;
1863	}
1864	else
1865	{
1866	ras.clip_box.xMin = -(1 << 23);
1867	ras.clip_box.yMin = -(1 << 23);
1868	ras.clip_box.xMax = (1 << 23) - 1;
1869	ras.clip_box.yMax = (1 << 23) - 1;
1870	}
1871
1872	gray_init_cells( worker, buffer: raster->buffer, byte_size: raster->buffer_size );
1873
1874	ras.outline = *outline;
1875	ras.num_cells = 0;
1876	ras.invalid = 1;
1877	ras.band_size = raster->band_size;
1878
1879	if ( target_map )
1880	ras.target = *target_map;
1881
1882	ras.render_span = (QT_FT_Raster_Span_Func)gray_render_span;
1883	ras.render_span_data = &ras;
1884
1885	if ( params->flags & QT_FT_RASTER_FLAG_DIRECT )
1886	{
1887	ras.render_span = (QT_FT_Raster_Span_Func)params->gray_spans;
1888	ras.render_span_data = params->user;
1889	}
1890
1891	return gray_convert_glyph( worker );
1892	}
1893
1894
1895	/**** RASTER OBJECT CREATION: In standalone mode, we simply use *****/
1896	/**** a static object. *****/
1897
1898	static int
1899	gray_raster_new( QT_FT_Raster* araster )
1900	{
1901	*araster = malloc(size: sizeof(TRaster));
1902	if (!*araster) {
1903	*araster = 0;
1904	return ErrRaster_Memory_Overflow;
1905	}
1906	QT_FT_MEM_ZERO(*araster, sizeof(TRaster));
1907
1908	return 0;
1909	}
1910
1911
1912	static void
1913	gray_raster_done( QT_FT_Raster raster )
1914	{
1915	free(ptr: raster);
1916	}
1917
1918
1919	static void
1920	gray_raster_reset( QT_FT_Raster raster,
1921	char* pool_base,
1922	long pool_size )
1923	{
1924	PRaster rast = (PRaster)raster;
1925
1926	if ( raster )
1927	{
1928	if ( pool_base && ( pool_size >= MINIMUM_POOL_SIZE ) )
1929	{
1930	PWorker worker = (PWorker)pool_base;
1931
1932
1933	rast->worker = worker;
1934	rast->buffer = pool_base +
1935	( ( sizeof ( TWorker ) + sizeof ( TCell ) - 1 ) &
1936	~( sizeof ( TCell ) - 1 ) );
1937	rast->buffer_size = (long)( ( pool_base + pool_size ) -
1938	(char*)rast->buffer ) &
1939	~( sizeof ( TCell ) - 1 );
1940	rast->band_size = (int)( rast->buffer_size /
1941	( sizeof ( TCell ) * 8 ) );
1942	}
1943	else if ( pool_base)
1944	{ /* Case when there is a raster pool allocated, but it */
1945	/* doesn't have the minimum size (and so memory will be reallocated) */
1946	rast->buffer = pool_base;
1947	rast->worker = NULL;
1948	rast->buffer_size = pool_size;
1949	}
1950	else
1951	{
1952	rast->buffer = NULL;
1953	rast->buffer_size = 0;
1954	rast->worker = NULL;
1955	}
1956	rast->buffer_allocated_size = pool_size;
1957	}
1958	}
1959
1960	const QT_FT_Raster_Funcs qt_ft_grays_raster =
1961	{
1962	QT_FT_GLYPH_FORMAT_OUTLINE,
1963
1964	(QT_FT_Raster_New_Func) gray_raster_new,
1965	(QT_FT_Raster_Reset_Func) gray_raster_reset,
1966	(QT_FT_Raster_Set_Mode_Func)0,
1967	(QT_FT_Raster_Render_Func) gray_raster_render,
1968	(QT_FT_Raster_Done_Func) gray_raster_done
1969	};
1970
1971	/* END */
1972