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/*
SCREENTextBounds.c
AUTHORS:
Allen.Ingling@nyu.edu awi
mario.kleiner.de@gmail.com mk
PLATFORMS:
All.
HISTORY:
1/19/04 awi Wrote it.
11/1/05 mk Resynced implementation with changes in SCREENDrawText.
1/29/06 mk Implemented Windows-Version of it.
3/7/06 awi Changed references from "Font" to "FontInfo". The function had been previously renamed, but not all references updated.
12/27/09 mk Massive refactoring of code for all platforms and support for plugin-based textrenderers. Now one shared implementation for
all platforms, because PsychDrawUnicodeText() does the main share of work if called in special "boundingbox" mode.
DESCRIPTION:
Compute local and global bounding box for a given textstring at given location, size, font and style.
*/
#include "Screen.h"
// If you change useString then also change the corresponding synopsis string in ScreenSynopsis.c
static char useString[] = "[normBoundsRect, offsetBoundsRect, textHeight, xAdvance] = Screen('TextBounds', windowPtr, text [,x] [,y] [,yPositionIsBaseline] [,swapTextDirection]);";
// 1 2 3 4 1 2 3 4 5 6
static char synopsisString[] =
"Accepts a window pointer and a 'text' string. Return in 'normBoundsRect' a rect defining the size of the text "
"in units of pixels. Returns in 'offsetBoundsRect' offsets of the text bounds from the origin, assuming "
"that the text will be drawn at the current position of the text drawing cursor. Only the default high "
"quality text renderers return a perfect bounding box. The optionally selectable low-quality, fast renderers "
"on Windows and Linux return a bounding box which doesn't take letters with descenders into account "
"- Descenders are outside the returned box.\n"
"\"textHeight\" optionally return height of current text string. May return zero if this is "
"not supported by the current text renderer.\n"
"\"xAdvance\" optionally return horizontal advance after drawing the text string. May return zero if this is "
"not supported by the current text renderer.\n"
"See help for Screen('DrawText') for info about accepted text string formats and all additional parameters... ";
static char seeAlsoString[] = "DrawText TextSize TextFont TextStyle TextColor TextBackgroundColor";
PsychError SCREENTextBounds(void)
{
PsychWindowRecordType *winRec;
PsychRectType resultPsychRect, resultPsychNormRect;
int yPositionIsBaseline, swapTextDirection;
int stringLengthChars;
double* textUniDoubleString;
double theight = 0;
double xAdvance = 0;
//all subfunctions should have these two lines.
PsychPushHelp(useString, synopsisString, seeAlsoString);
if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
//check for correct the number of arguments before getting involved
PsychErrorExit(PsychCapNumInputArgs(6));
PsychErrorExit(PsychRequireNumInputArgs(2));
PsychErrorExit(PsychCapNumOutputArgs(4));
// Get the window record:
PsychAllocInWindowRecordArg(1, kPsychArgRequired, &winRec);
// Check if input text string is present, valid and non-empty, get it as double vector
// of unicode characters: If this returns false then there ain't any work for us to do:
if (!PsychAllocInTextAsUnicode(2, kPsychArgRequired, &stringLengthChars, &textUniDoubleString)) {
PsychErrorExitMsg(PsychError_user, "You asked me to compute the bounding box of an empty text string?!? Sorry, that's a no no...");
}
// Get starting position for text cursor: This is optional.
PsychCopyInDoubleArg(3, kPsychArgOptional, &(winRec->textAttributes.textPositionX));
PsychCopyInDoubleArg(4, kPsychArgOptional, &(winRec->textAttributes.textPositionY));
// Define the meaning of the y position of the specified drawing cursor.
// We get the global setting from the Screen preference, but allow to override
// it on a per-invocation basis via the optional 7th argument to 'DrawText':
yPositionIsBaseline = PsychPrefStateGet_TextYPositionIsBaseline();
PsychCopyInIntegerArg(5, kPsychArgOptional, &yPositionIsBaseline);
// Get optional text writing direction flag: Defaults to left->right aka 0:
swapTextDirection = 0;
PsychCopyInIntegerArg(6, kPsychArgOptional, &swapTextDirection);
// This will perform the bounding box measurement and return the absolute bounding box in "resultPsychRect":
PsychDrawUnicodeText(winRec, &resultPsychRect, stringLengthChars, textUniDoubleString, &(winRec->textAttributes.textPositionX), &(winRec->textAttributes.textPositionY), &theight, &xAdvance, yPositionIsBaseline, &(winRec->textAttributes.textColor), &(winRec->textAttributes.textBackgroundColor), swapTextDirection);
// Create normalized version with top-left corner in (0,0):
PsychNormalizeRect(resultPsychRect, resultPsychNormRect);
// Return resulting bounding boxes:
PsychCopyOutRectArg(1, FALSE, resultPsychNormRect);
PsychCopyOutRectArg(2, FALSE, resultPsychRect);
PsychCopyOutDoubleArg(3, FALSE, theight);
PsychCopyOutDoubleArg(4, FALSE, xAdvance);
return(PsychError_none);
}
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