ref: 2067c6985ac896523afd0dc7327f317d766fc82d
dir: /src/cff/cf2stack.c/
/***************************************************************************/
/* */
/* cf2stack.c */
/* */
/* Adobe's code for emulating a CFF stack (body). */
/* */
/* Copyright 2007-2013 Adobe Systems Incorporated. */
/* */
/* This software, and all works of authorship, whether in source or */
/* object code form as indicated by the copyright notice(s) included */
/* herein (collectively, the "Work") is made available, and may only be */
/* used, modified, and distributed under the FreeType Project License, */
/* LICENSE.TXT. Additionally, subject to the terms and conditions of the */
/* FreeType Project License, each contributor to the Work hereby grants */
/* to any individual or legal entity exercising permissions granted by */
/* the FreeType Project License and this section (hereafter, "You" or */
/* "Your") a perpetual, worldwide, non-exclusive, no-charge, */
/* royalty-free, irrevocable (except as stated in this section) patent */
/* license to make, have made, use, offer to sell, sell, import, and */
/* otherwise transfer the Work, where such license applies only to those */
/* patent claims licensable by such contributor that are necessarily */
/* infringed by their contribution(s) alone or by combination of their */
/* contribution(s) with the Work to which such contribution(s) was */
/* submitted. If You institute patent litigation against any entity */
/* (including a cross-claim or counterclaim in a lawsuit) alleging that */
/* the Work or a contribution incorporated within the Work constitutes */
/* direct or contributory patent infringement, then any patent licenses */
/* granted to You under this License for that Work shall terminate as of */
/* the date such litigation is filed. */
/* */
/* By using, modifying, or distributing the Work you indicate that you */
/* have read and understood the terms and conditions of the */
/* FreeType Project License as well as those provided in this section, */
/* and you accept them fully. */
/* */
/***************************************************************************/
#include "cf2ft.h"
#include FT_INTERNAL_DEBUG_H
#include "cf2glue.h"
#include "cf2font.h"
#include "cf2stack.h"
#include "cf2error.h"
/* Allocate and initialize an instance of CF2_Stack. */
/* Note: This function returns NULL on error (does not set */
/* `error'). */
FT_LOCAL_DEF( CF2_Stack )
cf2_stack_init( FT_Memory memory,
FT_Error* e )
{
FT_Error error = FT_Err_Ok; /* for FT_NEW */
CF2_Stack stack = NULL;
if ( !FT_NEW( stack ) )
{
/* initialize the structure; FT_NEW zeroes it */
stack->memory = memory;
stack->error = e;
stack->top = &stack->buffer[0]; /* empty stack */
}
return stack;
}
FT_LOCAL_DEF( void )
cf2_stack_free( CF2_Stack stack )
{
if ( stack )
{
FT_Memory memory = stack->memory;
/* free the main structure */
FT_FREE( stack );
}
}
FT_LOCAL_DEF( CF2_UInt )
cf2_stack_count( CF2_Stack stack )
{
return (CF2_UInt)( stack->top - &stack->buffer[0] );
}
FT_LOCAL_DEF( void )
cf2_stack_pushInt( CF2_Stack stack,
CF2_Int val )
{
if ( stack->top == &stack->buffer[CF2_OPERAND_STACK_SIZE] )
{
CF2_SET_ERROR( stack->error, Stack_Overflow );
return; /* stack overflow */
}
stack->top->u.i = val;
stack->top->type = CF2_NumberInt;
++stack->top;
}
FT_LOCAL_DEF( void )
cf2_stack_pushFixed( CF2_Stack stack,
CF2_Fixed val )
{
if ( stack->top == &stack->buffer[CF2_OPERAND_STACK_SIZE] )
{
CF2_SET_ERROR( stack->error, Stack_Overflow );
return; /* stack overflow */
}
stack->top->u.r = val;
stack->top->type = CF2_NumberFixed;
++stack->top;
}
/* this function is only allowed to pop an integer type */
FT_LOCAL_DEF( CF2_Int )
cf2_stack_popInt( CF2_Stack stack )
{
if ( stack->top == &stack->buffer[0] )
{
CF2_SET_ERROR( stack->error, Stack_Underflow );
return 0; /* underflow */
}
if ( stack->top[-1].type != CF2_NumberInt )
{
CF2_SET_ERROR( stack->error, Syntax_Error );
return 0; /* type mismatch */
}
--stack->top;
return stack->top->u.i;
}
/* Note: type mismatch is silently cast */
/* TODO: check this */
FT_LOCAL_DEF( CF2_Fixed )
cf2_stack_popFixed( CF2_Stack stack )
{
if ( stack->top == &stack->buffer[0] )
{
CF2_SET_ERROR( stack->error, Stack_Underflow );
return cf2_intToFixed( 0 ); /* underflow */
}
--stack->top;
switch ( stack->top->type )
{
case CF2_NumberInt:
return cf2_intToFixed( stack->top->u.i );
case CF2_NumberFrac:
return cf2_fracToFixed( stack->top->u.f );
default:
return stack->top->u.r;
}
}
/* Note: type mismatch is silently cast */
/* TODO: check this */
FT_LOCAL_DEF( CF2_Fixed )
cf2_stack_getReal( CF2_Stack stack,
CF2_UInt idx )
{
FT_ASSERT( cf2_stack_count( stack ) <= CF2_OPERAND_STACK_SIZE );
if ( idx >= cf2_stack_count( stack ) )
{
CF2_SET_ERROR( stack->error, Stack_Overflow );
return cf2_intToFixed( 0 ); /* bounds error */
}
switch ( stack->buffer[idx].type )
{
case CF2_NumberInt:
return cf2_intToFixed( stack->buffer[idx].u.i );
case CF2_NumberFrac:
return cf2_fracToFixed( stack->buffer[idx].u.f );
default:
return stack->buffer[idx].u.r;
}
}
FT_LOCAL( void )
cf2_stack_roll( CF2_Stack stack,
CF2_Int count,
CF2_Int shift )
{
/* we initialize this variable to avoid compiler warnings */
CF2_StackNumber last = { { 0 }, CF2_NumberInt };
CF2_Int start_idx, idx, i;
if ( count < 2 )
return; /* nothing to do (values 0 and 1), or undefined value */
if ( (CF2_UInt)count > cf2_stack_count( stack ) )
{
CF2_SET_ERROR( stack->error, Stack_Overflow );
return;
}
if ( shift < 0 )
shift = -( ( -shift ) % count );
else
shift %= count;
if ( shift == 0 )
return; /* nothing to do */
/* We use the following algorithm to do the rolling, */
/* which needs two temporary variables only. */
/* */
/* Example: */
/* */
/* count = 8 */
/* shift = 2 */
/* */
/* stack indices before roll: 7 6 5 4 3 2 1 0 */
/* stack indices after roll: 1 0 7 6 5 4 3 2 */
/* */
/* The value of index 0 gets moved to index 2, while */
/* the old value of index 2 gets moved to index 4, */
/* and so on. We thus have the following copying */
/* chains for shift value 2. */
/* */
/* 0 -> 2 -> 4 -> 6 -> 0 */
/* 1 -> 3 -> 5 -> 7 -> 1 */
/* */
/* If `count' and `shift' are incommensurable, we */
/* have a single chain only. Otherwise, increase */
/* the start index by 1 after the first chain, then */
/* do the next chain until all elements in all */
/* chains are handled. */
start_idx = -1;
idx = -1;
for ( i = 0; i < count; i++ )
{
CF2_StackNumber tmp;
if ( start_idx == idx )
{
start_idx++;
idx = start_idx;
last = stack->buffer[idx];
}
idx += shift;
if ( idx >= count )
idx -= count;
else if ( idx < 0 )
idx += count;
tmp = stack->buffer[idx];
stack->buffer[idx] = last;
last = tmp;
}
}
FT_LOCAL_DEF( void )
cf2_stack_clear( CF2_Stack stack )
{
stack->top = &stack->buffer[0];
}
/* END */