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Diffstat (limited to 'src/base/ftbbox.c')
-rw-r--r-- | src/base/ftbbox.c | 515 |
1 files changed, 0 insertions, 515 deletions
diff --git a/src/base/ftbbox.c b/src/base/ftbbox.c deleted file mode 100644 index 6e19da63c..000000000 --- a/src/base/ftbbox.c +++ /dev/null @@ -1,515 +0,0 @@ -/***************************************************************************/ -/* */ -/* ftbbox.c */ -/* */ -/* FreeType bbox computation (body). */ -/* */ -/* Copyright 1996-2017 by */ -/* David Turner, Robert Wilhelm, and Werner Lemberg. */ -/* */ -/* This file is part of the FreeType project, and may only be used */ -/* modified and distributed under the terms of the FreeType project */ -/* license, LICENSE.TXT. By continuing to use, modify, or distribute */ -/* this file you indicate that you have read the license and */ -/* understand and accept it fully. */ -/* */ -/***************************************************************************/ - - - /*************************************************************************/ - /* */ - /* This component has a _single_ role: to compute exact outline bounding */ - /* boxes. */ - /* */ - /*************************************************************************/ - - -#include <ft2build.h> -#include FT_INTERNAL_DEBUG_H - -#include FT_BBOX_H -#include FT_IMAGE_H -#include FT_OUTLINE_H -#include FT_INTERNAL_CALC_H -#include FT_INTERNAL_OBJECTS_H - - - typedef struct TBBox_Rec_ - { - FT_Vector last; - FT_BBox bbox; - - } TBBox_Rec; - - -#define FT_UPDATE_BBOX( p, bbox ) \ - FT_BEGIN_STMNT \ - if ( p->x < bbox.xMin ) \ - bbox.xMin = p->x; \ - if ( p->x > bbox.xMax ) \ - bbox.xMax = p->x; \ - if ( p->y < bbox.yMin ) \ - bbox.yMin = p->y; \ - if ( p->y > bbox.yMax ) \ - bbox.yMax = p->y; \ - FT_END_STMNT - -#define CHECK_X( p, bbox ) \ - ( p->x < bbox.xMin || p->x > bbox.xMax ) - -#define CHECK_Y( p, bbox ) \ - ( p->y < bbox.yMin || p->y > bbox.yMax ) - - - /*************************************************************************/ - /* */ - /* <Function> */ - /* BBox_Move_To */ - /* */ - /* <Description> */ - /* This function is used as a `move_to' emitter during */ - /* FT_Outline_Decompose(). It simply records the destination point */ - /* in `user->last'. We also update bbox in case contour starts with */ - /* an implicit `on' point. */ - /* */ - /* <Input> */ - /* to :: A pointer to the destination vector. */ - /* */ - /* <InOut> */ - /* user :: A pointer to the current walk context. */ - /* */ - /* <Return> */ - /* Always 0. Needed for the interface only. */ - /* */ - static int - BBox_Move_To( FT_Vector* to, - TBBox_Rec* user ) - { - FT_UPDATE_BBOX( to, user->bbox ); - - user->last = *to; - - return 0; - } - - - /*************************************************************************/ - /* */ - /* <Function> */ - /* BBox_Line_To */ - /* */ - /* <Description> */ - /* This function is used as a `line_to' emitter during */ - /* FT_Outline_Decompose(). It simply records the destination point */ - /* in `user->last'; no further computations are necessary because */ - /* bbox already contains both explicit ends of the line segment. */ - /* */ - /* <Input> */ - /* to :: A pointer to the destination vector. */ - /* */ - /* <InOut> */ - /* user :: A pointer to the current walk context. */ - /* */ - /* <Return> */ - /* Always 0. Needed for the interface only. */ - /* */ - static int - BBox_Line_To( FT_Vector* to, - TBBox_Rec* user ) - { - user->last = *to; - - return 0; - } - - - /*************************************************************************/ - /* */ - /* <Function> */ - /* BBox_Conic_Check */ - /* */ - /* <Description> */ - /* Find the extrema of a 1-dimensional conic Bezier curve and update */ - /* a bounding range. This version uses direct computation, as it */ - /* doesn't need square roots. */ - /* */ - /* <Input> */ - /* y1 :: The start coordinate. */ - /* */ - /* y2 :: The coordinate of the control point. */ - /* */ - /* y3 :: The end coordinate. */ - /* */ - /* <InOut> */ - /* min :: The address of the current minimum. */ - /* */ - /* max :: The address of the current maximum. */ - /* */ - static void - BBox_Conic_Check( FT_Pos y1, - FT_Pos y2, - FT_Pos y3, - FT_Pos* min, - FT_Pos* max ) - { - /* This function is only called when a control off-point is outside */ - /* the bbox that contains all on-points. It finds a local extremum */ - /* within the segment, equal to (y1*y3 - y2*y2)/(y1 - 2*y2 + y3). */ - /* Or, offsetting from y2, we get */ - - y1 -= y2; - y3 -= y2; - y2 += FT_MulDiv( y1, y3, y1 + y3 ); - - if ( y2 < *min ) - *min = y2; - if ( y2 > *max ) - *max = y2; - } - - - /*************************************************************************/ - /* */ - /* <Function> */ - /* BBox_Conic_To */ - /* */ - /* <Description> */ - /* This function is used as a `conic_to' emitter during */ - /* FT_Outline_Decompose(). It checks a conic Bezier curve with the */ - /* current bounding box, and computes its extrema if necessary to */ - /* update it. */ - /* */ - /* <Input> */ - /* control :: A pointer to a control point. */ - /* */ - /* to :: A pointer to the destination vector. */ - /* */ - /* <InOut> */ - /* user :: The address of the current walk context. */ - /* */ - /* <Return> */ - /* Always 0. Needed for the interface only. */ - /* */ - /* <Note> */ - /* In the case of a non-monotonous arc, we compute directly the */ - /* extremum coordinates, as it is sufficiently fast. */ - /* */ - static int - BBox_Conic_To( FT_Vector* control, - FT_Vector* to, - TBBox_Rec* user ) - { - /* in case `to' is implicit and not included in bbox yet */ - FT_UPDATE_BBOX( to, user->bbox ); - - if ( CHECK_X( control, user->bbox ) ) - BBox_Conic_Check( user->last.x, - control->x, - to->x, - &user->bbox.xMin, - &user->bbox.xMax ); - - if ( CHECK_Y( control, user->bbox ) ) - BBox_Conic_Check( user->last.y, - control->y, - to->y, - &user->bbox.yMin, - &user->bbox.yMax ); - - user->last = *to; - - return 0; - } - - - /*************************************************************************/ - /* */ - /* <Function> */ - /* BBox_Cubic_Check */ - /* */ - /* <Description> */ - /* Find the extrema of a 1-dimensional cubic Bezier curve and */ - /* update a bounding range. This version uses iterative splitting */ - /* because it is faster than the exact solution with square roots. */ - /* */ - /* <Input> */ - /* p1 :: The start coordinate. */ - /* */ - /* p2 :: The coordinate of the first control point. */ - /* */ - /* p3 :: The coordinate of the second control point. */ - /* */ - /* p4 :: The end coordinate. */ - /* */ - /* <InOut> */ - /* min :: The address of the current minimum. */ - /* */ - /* max :: The address of the current maximum. */ - /* */ - static FT_Pos - cubic_peak( FT_Pos q1, - FT_Pos q2, - FT_Pos q3, - FT_Pos q4 ) - { - FT_Pos peak = 0; - FT_Int shift; - - - /* This function finds a peak of a cubic segment if it is above 0 */ - /* using iterative bisection of the segment, or returns 0. */ - /* The fixed-point arithmetic of bisection is inherently stable */ - /* but may loose accuracy in the two lowest bits. To compensate, */ - /* we upscale the segment if there is room. Large values may need */ - /* to be downscaled to avoid overflows during bisection. */ - /* It is called with either q2 or q3 positive, which is necessary */ - /* for the peak to exist and avoids undefined FT_MSB. */ - - shift = 27 - FT_MSB( (FT_UInt32)( FT_ABS( q1 ) | - FT_ABS( q2 ) | - FT_ABS( q3 ) | - FT_ABS( q4 ) ) ); - - if ( shift > 0 ) - { - /* upscaling too much just wastes time */ - if ( shift > 2 ) - shift = 2; - - q1 <<= shift; - q2 <<= shift; - q3 <<= shift; - q4 <<= shift; - } - else - { - q1 >>= -shift; - q2 >>= -shift; - q3 >>= -shift; - q4 >>= -shift; - } - - /* for a peak to exist above 0, the cubic segment must have */ - /* at least one of its control off-points above 0. */ - while ( q2 > 0 || q3 > 0 ) - { - /* determine which half contains the maximum and split */ - if ( q1 + q2 > q3 + q4 ) /* first half */ - { - q4 = q4 + q3; - q3 = q3 + q2; - q2 = q2 + q1; - q4 = q4 + q3; - q3 = q3 + q2; - q4 = ( q4 + q3 ) / 8; - q3 = q3 / 4; - q2 = q2 / 2; - } - else /* second half */ - { - q1 = q1 + q2; - q2 = q2 + q3; - q3 = q3 + q4; - q1 = q1 + q2; - q2 = q2 + q3; - q1 = ( q1 + q2 ) / 8; - q2 = q2 / 4; - q3 = q3 / 2; - } - - /* check whether either end reached the maximum */ - if ( q1 == q2 && q1 >= q3 ) - { - peak = q1; - break; - } - if ( q3 == q4 && q2 <= q4 ) - { - peak = q4; - break; - } - } - - if ( shift > 0 ) - peak >>= shift; - else - peak <<= -shift; - - return peak; - } - - - static void - BBox_Cubic_Check( FT_Pos p1, - FT_Pos p2, - FT_Pos p3, - FT_Pos p4, - FT_Pos* min, - FT_Pos* max ) - { - /* This function is only called when a control off-point is outside */ - /* the bbox that contains all on-points. So at least one of the */ - /* conditions below holds and cubic_peak is called with at least one */ - /* non-zero argument. */ - - if ( p2 > *max || p3 > *max ) - *max += cubic_peak( p1 - *max, p2 - *max, p3 - *max, p4 - *max ); - - /* now flip the signs to update the minimum */ - if ( p2 < *min || p3 < *min ) - *min -= cubic_peak( *min - p1, *min - p2, *min - p3, *min - p4 ); - } - - - /*************************************************************************/ - /* */ - /* <Function> */ - /* BBox_Cubic_To */ - /* */ - /* <Description> */ - /* This function is used as a `cubic_to' emitter during */ - /* FT_Outline_Decompose(). It checks a cubic Bezier curve with the */ - /* current bounding box, and computes its extrema if necessary to */ - /* update it. */ - /* */ - /* <Input> */ - /* control1 :: A pointer to the first control point. */ - /* */ - /* control2 :: A pointer to the second control point. */ - /* */ - /* to :: A pointer to the destination vector. */ - /* */ - /* <InOut> */ - /* user :: The address of the current walk context. */ - /* */ - /* <Return> */ - /* Always 0. Needed for the interface only. */ - /* */ - /* <Note> */ - /* In the case of a non-monotonous arc, we don't compute directly */ - /* extremum coordinates, we subdivide instead. */ - /* */ - static int - BBox_Cubic_To( FT_Vector* control1, - FT_Vector* control2, - FT_Vector* to, - TBBox_Rec* user ) - { - /* We don't need to check `to' since it is always an on-point, */ - /* thus within the bbox. Only segments with an off-point outside */ - /* the bbox can possibly reach new extreme values. */ - - if ( CHECK_X( control1, user->bbox ) || - CHECK_X( control2, user->bbox ) ) - BBox_Cubic_Check( user->last.x, - control1->x, - control2->x, - to->x, - &user->bbox.xMin, - &user->bbox.xMax ); - - if ( CHECK_Y( control1, user->bbox ) || - CHECK_Y( control2, user->bbox ) ) - BBox_Cubic_Check( user->last.y, - control1->y, - control2->y, - to->y, - &user->bbox.yMin, - &user->bbox.yMax ); - - user->last = *to; - - return 0; - } - - - FT_DEFINE_OUTLINE_FUNCS( - bbox_interface, - - (FT_Outline_MoveTo_Func) BBox_Move_To, /* move_to */ - (FT_Outline_LineTo_Func) BBox_Line_To, /* line_to */ - (FT_Outline_ConicTo_Func)BBox_Conic_To, /* conic_to */ - (FT_Outline_CubicTo_Func)BBox_Cubic_To, /* cubic_to */ - 0, /* shift */ - 0 /* delta */ - ) - - - /* documentation is in ftbbox.h */ - - FT_EXPORT_DEF( FT_Error ) - FT_Outline_Get_BBox( FT_Outline* outline, - FT_BBox *abbox ) - { - FT_BBox cbox = { 0x7FFFFFFFL, 0x7FFFFFFFL, - -0x7FFFFFFFL, -0x7FFFFFFFL }; - FT_BBox bbox = { 0x7FFFFFFFL, 0x7FFFFFFFL, - -0x7FFFFFFFL, -0x7FFFFFFFL }; - FT_Vector* vec; - FT_UShort n; - - - if ( !abbox ) - return FT_THROW( Invalid_Argument ); - - if ( !outline ) - return FT_THROW( Invalid_Outline ); - - /* if outline is empty, return (0,0,0,0) */ - if ( outline->n_points == 0 || outline->n_contours <= 0 ) - { - abbox->xMin = abbox->xMax = 0; - abbox->yMin = abbox->yMax = 0; - - return 0; - } - - /* We compute the control box as well as the bounding box of */ - /* all `on' points in the outline. Then, if the two boxes */ - /* coincide, we exit immediately. */ - - vec = outline->points; - - for ( n = 0; n < outline->n_points; n++ ) - { - FT_UPDATE_BBOX( vec, cbox ); - - if ( FT_CURVE_TAG( outline->tags[n] ) == FT_CURVE_TAG_ON ) - FT_UPDATE_BBOX( vec, bbox ); - - vec++; - } - - /* test two boxes for equality */ - if ( cbox.xMin < bbox.xMin || cbox.xMax > bbox.xMax || - cbox.yMin < bbox.yMin || cbox.yMax > bbox.yMax ) - { - /* the two boxes are different, now walk over the outline to */ - /* get the Bezier arc extrema. */ - - FT_Error error; - TBBox_Rec user; - -#ifdef FT_CONFIG_OPTION_PIC - FT_Outline_Funcs bbox_interface; - - - Init_Class_bbox_interface( &bbox_interface ); -#endif - - user.bbox = bbox; - - error = FT_Outline_Decompose( outline, &bbox_interface, &user ); - if ( error ) - return error; - - *abbox = user.bbox; - } - else - *abbox = bbox; - - return FT_Err_Ok; - } - - -/* END */ |