vg_helper.c File Reference

MicroEJ MicroVG library low level API: helper to implement library natives methods. More...

#include "vg_configuration.h"
#include <LLVG_MATRIX_impl.h>
#include "vg_helper.h"
#include "vg_trace.h"
#include "vg_drawing.h"
#include "bsp_util.h"

Go to the source code of this file.

Macros
#define	MIN_HIGH_SURROGATE   ((unsigned short)0xD800)
#define	MAX_HIGH_SURROGATE   ((unsigned short)0xDBFF)
#define	MIN_LOW_SURROGATE   ((unsigned short)0xDC00)
#define	MAX_LOW_SURROGATE   ((unsigned short)0xDFFF)
#define	MIN_SUPPLEMENTARY_CODE_POINT   0x010000
#define	GET_NEXT_CHARACTER(t, l, o)   ((o) >= (l) ? (unsigned short)0 : (t)[o])
#define	IS_SIMPLE_LAYOUT   true

Functions
void	LLVG_IMPL_initialize (jint trace_group)
BSP_DECLARE_WEAK_FCNT void	LLUI_DISPLAY_waitAsynchronousDrawingEnd (void)
	Waits until the end of current asynchronous drawing. More...
int	VG_HELPER_get_utf (const unsigned short *textCharRam, int length, int *offset)
	Gets the UTF character from a text buffer at the given offset and updates the offset to point to the next character. More...
const jfloat *	VG_HELPER_check_matrix (const jfloat *matrix)
uint32_t	VG_HELPER_apply_alpha (uint32_t color, uint32_t alpha)
void	VG_HELPER_prepare_matrix (jfloat *dest, jfloat x, jfloat y, const jfloat *matrix)

Variables
int32_t	LLVG_TRACE_group

Detailed Description

MicroEJ MicroVG library low level API: helper to implement library natives methods.

Author

MicroEJ Developer Team

Version

8.0.0

Definition in file vg_helper.c.

Function Documentation

LLUI_DISPLAY_waitAsynchronousDrawingEnd()

BSP_DECLARE_WEAK_FCNT void LLUI_DISPLAY_waitAsynchronousDrawingEnd

(

void

)

Waits until the end of current asynchronous drawing.

To avoid potential side effects from the release of objects (images, fonts) retained by a feature during the killing of that feature, ensure that no third-party components (e.g., GPU) are using these objects at the time of the kill.

UI packs with versions higher than 14.5.1 provide the blocking API LLUI_DISPLAY_waitAsynchronousDrawingEnd(). This API is stubbed on the VG Pack for backward compatibility issues between VG Pack 1.8.0 and UI Packs [14.4.0, 14.5.1]. However, it is highly recommended to use a UI Pack version greater than 14.5.1.

Definition at line 150 of file vg_helper.c.

                                                                         {
    // cannot wait the end of drawing with UI packs [14.4.0-14.5.1]
}

VG_HELPER_get_utf()

int VG_HELPER_get_utf	(	const unsigned short *	text,
		int	length,
		int *	offset
	)

Gets the UTF character from a text buffer at the given offset and updates the offset to point to the next character.

Some characters have some special values; they are made up of two Unicode characters in two specific ranges such that the first Unicode character is in one range (for example 0xD800-0xD8FF) and the second Unicode character is in the second range (for example 0xDC00-0xDCFF). This is called a surrogate pair.

If a surrogate pair is incomplete (missing second character), this function returns "0" (error) and does not update the offset.

Parameters

[in]	text	text buffer encoded in UTF16 where to read UTF character.
[in]	length	lenght of the text buffer.
	[in/out]	offset: offset in the text buffer where to read UTF character. Updated to the next character position.

Returns

The decoded UTF character.

Definition at line 159 of file vg_helper.c.

                                                                                  {
    unsigned short highPart = GET_NEXT_CHARACTER(textCharRam, length, *offset);
    int ret = 0; // means "error" (see doc)
 
    if ((highPart >= MIN_HIGH_SURROGATE) && (highPart <= MAX_HIGH_SURROGATE)) {
        if (*offset < (length - 1)) {
            unsigned short lowPart = GET_NEXT_CHARACTER(textCharRam, length, *(offset) + 1);
 
            if ((lowPart >= MIN_LOW_SURROGATE) && (lowPart <= MAX_LOW_SURROGATE)) {
                *offset += 2;
 
                ret = 0;
                ret += ((int)highPart - (int)MIN_HIGH_SURROGATE);
                ret <<= (int)10;
                ret += ((int)lowPart - (int)MIN_LOW_SURROGATE);
                ret += (int)MIN_SUPPLEMENTARY_CODE_POINT;
            }
            // else: invalid surrogate pair
        }
        // else: missing second part of surrogate pair
    } else {
        *offset += 1;
 
        // standard character
        ret = 0x0000FFFF & (int)highPart;
    }
 
    return ret;
}