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https://github.com/adafruit/Adafruit-GFX-Library.git
synced 2024-10-03 18:18:46 -04:00
Added getTextBounds() optional arguments xF and yF, with extensive comments in .cpp file.
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Ted Toal
parent
15ebe114c4
commit
982d028ce3
135
Adafruit_GFX.cpp
135
Adafruit_GFX.cpp
@ -1356,9 +1356,9 @@ void Adafruit_GFX::setFont(const GFXfont *f) {
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Broke this out as it's used by both the PROGMEM- and RAM-resident
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getTextBounds() functions.
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@param c The ASCII character in question
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@param x Pointer to x location of character. Value is modified by
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@param x Pointer to x cursor position of character. Value is modified by
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this function to advance to next character.
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@param y Pointer to y location of character. Value is modified by
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@param y Pointer to y cursor position of character. Value is modified by
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this function to advance to next character.
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@param minx Pointer to minimum X coordinate, passed in to AND returned
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by this function -- this is used to incrementally build a
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@ -1435,26 +1435,86 @@ void Adafruit_GFX::charBounds(unsigned char c, int16_t *x, int16_t *y,
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/**************************************************************************/
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/*!
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@brief Helper to determine size of a string with current font/size.
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Pass string and a cursor position, returns UL corner and W,H.
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@param str The ASCII string to measure
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@param x The current cursor X
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@param y The current cursor Y
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@param x1 The boundary X coordinate, returned by function
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@param y1 The boundary Y coordinate, returned by function
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@param w The boundary width, returned by function
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@param h The boundary height, returned by function
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Pass string and a cursor position, returns UL corner, baseline Y,
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and W,H.
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@param str ASCII string to measure
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@param x Starting cursor X (left side, first character)
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@param y Starting cursor Y (on baseline, first character)
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@param xL Left text boundary X coordinate, returned by function
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@param yT Top text boundary Y coordinate, returned by function
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@param w Text boundary width, returned by function
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@param h Text boundary height, returned by function
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@param xF Ending cursor X (right side of baseline, last char), if not NULL
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@param yF Ending cursor Y (on baseline, last char), returned if not NULL
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@notes The values of (x, y) on call to this function actually don't
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matter to it; they are simply incremented past the string
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bounds. However, they COULD BE the CURSOR POSITION used in a
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call to setCursor(). More often, the reason for calling this
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function is to get the text size so that the starting cursor
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position can be adjusted (e.g. for center alignment), so the
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cursor position is unknown when this function is called, and
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(x, y) can really just be arbitrary values.
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Since the returned (xL, yT) values are the coords of the upper
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left corner of the text boundary box, then the correct CURSOR
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position to use with setCursor() when printing the text, if
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the upper-left corner of the text is to be at position (X1,Y1)
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(which may or may not equal the (x, y) arguments to this
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function), is:
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(X1+x-xL, Y1+y-yT)
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Suppose (x, y) are indeed set to (X1, Y1) when calling this
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function. In that case (x-XL) and (y-yT) will evaluate to a
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small positive or negative integer, possibly 0 but not always
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0, and adding that small integer to X1 and Y1 will move them
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slightly so they can be used in a call to setCursor(). The
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cursor position is NOT the upper-left corner of the next
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character to be printed. Rather, it is a position on the TEXT
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BASELINE (bottom of characters that don't have descenders on
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them), used to align the character font data. (y-yT) will
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almost always be a positive value that is the distance from
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the top of the text (yT) to the text baseline. Note that the
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text baseline is NOT Y1+h, because h includes the full string
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height including descenders on characters.
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If instead of the above setting, the cursor position for
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displaying the string is set to (X1, Y1+h), the text will be
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shifted left or right slightly when the first character starts
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slightly left or right of the cursor position (which some
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characters do), and the text will be shifted up if it contains
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any characters with descenders that extend below the baseline.
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The optional arguments xF and yF provide a way to discover
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where to start adding more characters after the string, if
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desired. The final cursor position is returned in (xF, yF).
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This is NOT the same as (xL+w, yT+h). Instead, XF might be
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slightly more or less than that, while yF is probably the same
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as the y value given at the start (unless there was text
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wrapping). The final CURSOR position to use to print additional
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text after the string, if the upper-left corner of the text is
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at position (X1, Y1), is:
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(X1+xF-xL, Y1+yF-yT)
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The position of the lower-right corner of the bounding box,
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(X2, Y2), is of course:
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(X1+w, Y1+h)
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If another character is printed after the string, using the
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starting cursor position (X1+xF-xL, Y1+yF-yT), and that new
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character has top-left bound box offset (dX, dY) and width
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W and height H, then the new lower-right corner of the bounding
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box (X2, Y2) is:
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(X1+xF-xL+dX+W, Y1+yF-yT+max(0, dY+H))
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and so the new total text string width and height are:
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new w = xF-xL+dX+W = new X2 - X1
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new h = yF-yT+max(0, dY+H) = new Y2 - Y1
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*/
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/**************************************************************************/
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void Adafruit_GFX::getTextBounds(const char *str, int16_t x, int16_t y,
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int16_t *x1, int16_t *y1, uint16_t *w,
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uint16_t *h) {
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int16_t *xL, int16_t *yT,
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uint16_t *w, uint16_t *h,
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int16_t *xF, int16_t *yF) {
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uint8_t c; // Current character
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int16_t minx = 0x7FFF, miny = 0x7FFF, maxx = -1, maxy = -1; // Bound rect
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// Bound rect is intentionally initialized inverted, so 1st char sets it
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*x1 = x; // Initial position is value passed in
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*y1 = y;
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*xL = x; // This initialization SHOULD be overwritten below after charBounds()
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*yT = y; // is called. (Unless string is empty).
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*w = *h = 0; // Initial size is zero
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while ((c = *str++)) {
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@ -1464,13 +1524,20 @@ void Adafruit_GFX::getTextBounds(const char *str, int16_t x, int16_t y,
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}
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if (maxx >= minx) { // If legit string bounds were found...
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*x1 = minx; // Update x1 to least X coord,
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*xL = minx; // Update xL to least X coord,
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*w = maxx - minx + 1; // And w to bound rect width
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}
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if (maxy >= miny) { // Same for height
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*y1 = miny;
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if (maxy >= miny) { // Same for height as for width
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*yT = miny;
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*h = maxy - miny + 1;
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}
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// If xF and yF arguments provided, return final cursor x and y position.
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if (xF != NULL)
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*xF = x;
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if (yF != NULL)
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*yF = y;
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}
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/**************************************************************************/
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@ -1480,17 +1547,18 @@ void Adafruit_GFX::getTextBounds(const char *str, int16_t x, int16_t y,
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@param str The ascii string to measure (as an arduino String() class)
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@param x The current cursor X
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@param y The current cursor Y
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@param x1 The boundary X coordinate, set by function
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@param y1 The boundary Y coordinate, set by function
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@param xL The left boundary X coordinate, set by function
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@param yT The top boundary Y coordinate, set by function
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@param w The boundary width, set by function
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@param h The boundary height, set by function
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*/
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/**************************************************************************/
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void Adafruit_GFX::getTextBounds(const String &str, int16_t x, int16_t y,
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int16_t *x1, int16_t *y1, uint16_t *w,
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uint16_t *h) {
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int16_t *xL, int16_t *yT,
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uint16_t *w, uint16_t *h,
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int16_t *xF, int16_t *yF) {
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if (str.length() != 0) {
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getTextBounds(const_cast<char *>(str.c_str()), x, y, x1, y1, w, h);
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getTextBounds(const_cast<char *>(str.c_str()), x, y, xL, yT, w, h, xF, yF);
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}
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}
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@ -1501,19 +1569,20 @@ void Adafruit_GFX::getTextBounds(const String &str, int16_t x, int16_t y,
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@param str The flash-memory ascii string to measure
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@param x The current cursor X
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@param y The current cursor Y
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@param x1 The boundary X coordinate, set by function
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@param y1 The boundary Y coordinate, set by function
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@param xL The left boundary X coordinate, set by function
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@param yT The top boundary Y coordinate, set by function
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@param w The boundary width, set by function
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@param h The boundary height, set by function
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*/
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/**************************************************************************/
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void Adafruit_GFX::getTextBounds(const __FlashStringHelper *str, int16_t x,
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int16_t y, int16_t *x1, int16_t *y1,
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uint16_t *w, uint16_t *h) {
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int16_t y, int16_t *xL, int16_t *yT,
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uint16_t *w, uint16_t *h,
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int16_t *xF, int16_t *yF) {
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uint8_t *s = (uint8_t *)str, c;
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*x1 = x;
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*y1 = y;
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*xL = x;
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*yT = y;
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*w = *h = 0;
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int16_t minx = _width, miny = _height, maxx = -1, maxy = -1;
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@ -1522,13 +1591,19 @@ void Adafruit_GFX::getTextBounds(const __FlashStringHelper *str, int16_t x,
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charBounds(c, &x, &y, &minx, &miny, &maxx, &maxy);
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if (maxx >= minx) {
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*x1 = minx;
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*xL = minx;
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*w = maxx - minx + 1;
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}
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if (maxy >= miny) {
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*y1 = miny;
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*yT = miny;
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*h = maxy - miny + 1;
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}
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// If xF and yF arguments provided, return final cursor x and y position.
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if (xF != NULL)
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*xF = x;
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if (yF != NULL)
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*yF = y;
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}
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/**************************************************************************/
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@ -111,12 +111,15 @@ public:
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uint16_t bg, uint8_t size);
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void drawChar(int16_t x, int16_t y, unsigned char c, uint16_t color,
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uint16_t bg, uint8_t size_x, uint8_t size_y);
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void getTextBounds(const char *string, int16_t x, int16_t y, int16_t *x1,
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int16_t *y1, uint16_t *w, uint16_t *h);
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void getTextBounds(const char *string, int16_t x, int16_t y,
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int16_t *xL, int16_t *yT, uint16_t *w, uint16_t *h,
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int16_t *xF=NULL, int16_t *yF=NULL);
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void getTextBounds(const __FlashStringHelper *s, int16_t x, int16_t y,
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int16_t *x1, int16_t *y1, uint16_t *w, uint16_t *h);
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void getTextBounds(const String &str, int16_t x, int16_t y, int16_t *x1,
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int16_t *y1, uint16_t *w, uint16_t *h);
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int16_t *xL, int16_t *yT, uint16_t *w, uint16_t *h,
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int16_t *xF=NULL, int16_t *yF=NULL);
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void getTextBounds(const String &str, int16_t x, int16_t y,
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int16_t *xL, int16_t *yT, uint16_t *w, uint16_t *h,
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int16_t *xF=NULL, int16_t *yF=NULL);
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void setTextSize(uint8_t s);
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void setTextSize(uint8_t sx, uint8_t sy);
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void setFont(const GFXfont *f = NULL);
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