Debug Traces

MicroVG logs several actions when traces are enabled. This chapter explains the trace identifiers.

Note

The logs are only available on the Embedded VEE Port (not on the Simulator).

Trace format

The trace output format is the following:

[TRACE: MicroVG] Event AA(BB[CC])

where:

AA is the event identifier. See next table.
BB is the event data.
CC is the index of the event data (0x0).

For example, given the following trace output:

[TRACE: MicroVG] Event 0x2(2[0x0])

0x2 -> Execute drawing event
2 -> Event “Draw String” (index 0x0)

Trace identifiers

The following tables describe some events data.

MicroVG Traces
Event ID	Description	End of event
0x0 (0)	Image event `%0%` (see Image Type).	End of `%0%` (see Image Type).
0x1 (1)	Font event `%0%` (see Font Type).	End of `%0%` (see Font Type).
0x2 (2)	Drawing event `%0%` (see Drawing Type).	End of `%0%` (see Drawing Type).

Image Type
Event ID	Description
0x0 (0)	Get or load image from RAW file
0x1 (1)	Create BufferedVectorImage
0x2 (2)	Close image

Font Type
Event ID	Description
0x0 (0)	Load font from TTF / OTF file
0x1 (1)	Retrieve font baseline
0x2 (2)	Retrieve font height
0x3 (3)	Measure string width
0x4 (4)	Measure string height

Drawing Type
Event ID	Description
0x0 (0)	Fill path with a color
0x1 (1)	Fill path with a linear gradient
0x2 (2)	Draw string with a color
0x3 (3)	Draw string with a linear gradient
0x4 (4)	Draw string on a circle with a color
0x5 (5)	Draw string on a circle with a gradient
0x6 (6)	Draw image

SystemView Integration

The traces are SystemView compatible.

The following text can be copied in a file called SYSVIEW_MicroVG.txt and copied in SystemView installation folder (e.g. SEGGER/SystemView_V252a/Description/).

NamedType VGImage 0=LOAD_IMAGE
NamedType VGImage 1=CREATE_IMAGE
NamedType VGImage 2=CLOSE_IMAGE

NamedType VGFont 0=LOAD_FONT
NamedType VGFont 1=FONT_BASELINE
NamedType VGFont 2=FONT_HEIGHT
NamedType VGFont 3=STRING_WIDTH
NamedType VGFont 4=STRING_HEIGHT

NamedType VGDraw 0=DRAW_PATH
NamedType VGDraw 1=DRAW_PATH_GRADIENT
NamedType VGDraw 2=DRAW_STRING
NamedType VGDraw 3=DRAW_STRING_GRADIENT
NamedType VGDraw 4=DRAW_STRING_ON_CIRCLE
NamedType VGDraw 5=DRAW_STRING_ON_CIRCLE_GRADIENT
NamedType VGDraw 6=DRAW_IMAGE

0        VG_ImageEvent      (MicroVG) Execute image event %VGImage  | (MicroVG) Image event %VGImage done
1        VG_FontEvent       (MicroVG) Execute font event %VGFont  | (MicroVG) Font event %VGFont done
2        VG_DrawingEvent    (MicroVG) Execute drawing event %VGDraw  | (MicroVG) Drawing event %VGDraw done