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Fix clipping in fast H/V lines on canvases
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@PaintYourDragon
PaintYourDragon committed Oct 19, 2020
1 parent 8d7bdff commit f876b13
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Showing 2 changed files with 148 additions and 102 deletions.
248 changes: 147 additions & 101 deletions Adafruit_GFX.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1352,16 +1352,20 @@ void Adafruit_GFX::setFont(const GFXfont *f) {

/**************************************************************************/
/*!
@brief Helper to determine size of a character with current font/size.
Broke this out as it's used by both the PROGMEM- and RAM-resident
getTextBounds() functions.
@param c The ascii character in question
@param x Pointer to x location of character
@param y Pointer to y location of character
@param minx Minimum clipping value for X
@param miny Minimum clipping value for Y
@param maxx Maximum clipping value for X
@param maxy Maximum clipping value for Y
@brief Helper to determine size of a character with current font/size.
Broke this out as it's used by both the PROGMEM- and RAM-resident
getTextBounds() functions.
@param c The ASCII character in question
@param x Pointer to x location of character. Value is modified by
this function to advance to next character.
@param y Pointer to y location of character. Value is modified by
this function to advance to next character.
@param minx Pointer to minimum X coordinate, passed in to AND returned
by this function -- this is used to incrementally build a
bounding rectangle for a string.
@param miny Pointer to minimum Y coord, passed in AND returned.
@param maxx Pointer to maximum X coord, passed in AND returned.
@param maxy Pointer to maximum Y coord, passed in AND returned.
*/
/**************************************************************************/
void Adafruit_GFX::charBounds(unsigned char c, int16_t *x, int16_t *y,
Expand Down Expand Up @@ -1430,36 +1434,40 @@ void Adafruit_GFX::charBounds(unsigned char c, int16_t *x, int16_t *y,

/**************************************************************************/
/*!
@brief Helper to determine size of a string with current font/size. Pass
string and a cursor position, returns UL corner and W,H.
@param str The ascii string to measure
@param x The current cursor X
@param y The current cursor Y
@param x1 The boundary X coordinate, set by function
@param y1 The boundary Y coordinate, set by function
@param w The boundary width, set by function
@param h The boundary height, set by function
@brief Helper to determine size of a string with current font/size.
Pass string and a cursor position, returns UL corner and W,H.
@param str The ASCII string to measure
@param x The current cursor X
@param y The current cursor Y
@param x1 The boundary X coordinate, returned by function
@param y1 The boundary Y coordinate, returned by function
@param w The boundary width, returned by function
@param h The boundary height, returned by function
*/
/**************************************************************************/
void Adafruit_GFX::getTextBounds(const char *str, int16_t x, int16_t y,
int16_t *x1, int16_t *y1, uint16_t *w,
uint16_t *h) {

uint8_t c; // Current character
int16_t minx = 0x7FFF, miny = 0x7FFF, maxx = -1, maxy = -1; // Bound rect
// Bound rect is intentionally initialized inverted, so 1st char sets it

*x1 = x;
*x1 = x; // Initial position is value passed in
*y1 = y;
*w = *h = 0;
*w = *h = 0; // Initial size is zero

int16_t minx = _width, miny = _height, maxx = -1, maxy = -1;

while ((c = *str++))
while ((c = *str++)) {
// charBounds() modifies x/y to advance for each character,
// and min/max x/y are updated to incrementally build bounding rect.
charBounds(c, &x, &y, &minx, &miny, &maxx, &maxy);
}

if (maxx >= minx) {
*x1 = minx;
*w = maxx - minx + 1;
if (maxx >= minx) { // If legit string bounds were found...
*x1 = minx; // Update x1 to least X coord,
*w = maxx - minx + 1; // And w to bound rect width
}
if (maxy >= miny) {
if (maxy >= miny) { // Same for height
*y1 = miny;
*h = maxy - miny + 1;
}
Expand Down Expand Up @@ -1884,23 +1892,17 @@ void GFXcanvas1::fillScreen(uint16_t color) {

/**************************************************************************/
/*!
@brief Speed optimized vertical line drawing
@param x Line horizontal start point
@param y Line vertical start point
@param h length of vertical line to be drawn, including first point
@param color Binary (on or off) color to fill with
@brief Speed optimized vertical line drawing
@param x Line horizontal start point
@param y Line vertical start point
@param h Length of vertical line to be drawn, including first point
@param color Color to fill with
*/
/**************************************************************************/
void GFXcanvas1::drawFastVLine(int16_t x, int16_t y, int16_t h,
uint16_t color) {
if ((x < 0) || (x >= width()) || (y < 0) || (y >= height())) {
return;
}

if (y + h > height()) {
h = height() - y;
} else if (h < 0) {
// convert negative heights to their postive equivalent
if (h < 0) { // Convert negative heights to positive equivalent
h *= -1;
y -= h - 1;
if (y < 0) {
Expand All @@ -1909,6 +1911,19 @@ void GFXcanvas1::drawFastVLine(int16_t x, int16_t y, int16_t h,
}
}

// Edge rejection (no-draw if totally off canvas)
if ((x < 0) || (x >= width()) || (y >= height()) || ((y + h - 1) < 0)) {
return;
}

if (y < 0) { // Clip top
h += y;
y = 0;
}
if (y + h > height()) { // Clip bottom
h = height() - y;
}

if (getRotation() == 0) {
drawFastRawVLine(x, y, h, color);
} else if (getRotation() == 1) {
Expand All @@ -1933,23 +1948,16 @@ void GFXcanvas1::drawFastVLine(int16_t x, int16_t y, int16_t h,

/**************************************************************************/
/*!
@brief Speed optimized horizontal line drawing
@param x Line horizontal start point
@param y Line vertical start point
@param w length of horizontal line to be drawn, including first point
@param color Binary (on or off) color to fill with
@brief Speed optimized horizontal line drawing
@param x Line horizontal start point
@param y Line vertical start point
@param w Length of horizontal line to be drawn, including first point
@param color Color to fill with
*/
/**************************************************************************/
void GFXcanvas1::drawFastHLine(int16_t x, int16_t y, int16_t w,
uint16_t color) {
if ((x < 0) || (x >= width()) || (y < 0) || (y >= height())) {
return;
}

if (x + w > width()) {
w = width() - x;
} else if (w < 0) {
// convert negative widths to their postive equivalent
if (w < 0) { // Convert negative widths to positive equivalent
w *= -1;
x -= w - 1;
if (x < 0) {
Expand All @@ -1958,6 +1966,19 @@ void GFXcanvas1::drawFastHLine(int16_t x, int16_t y, int16_t w,
}
}

// Edge rejection (no-draw if totally off canvas)
if ((y < 0) || (y >= height()) || (x >= width()) || ((x + w - 1) < 0)) {
return;
}

if (x < 0) { // Clip left
w += x;
x = 0;
}
if (x + w >= width()) { // Clip right
w = width() - x;
}

if (getRotation() == 0) {
drawFastRawHLine(x, y, w, color);
} else if (getRotation() == 1) {
Expand Down Expand Up @@ -2206,24 +2227,17 @@ void GFXcanvas8::fillScreen(uint16_t color) {

/**************************************************************************/
/*!
@brief Speed optimized vertical line drawing
@param x Line horizontal start point
@param y Line vertical start point
@param h length of vertical line to be drawn, including first point
@param color 8-bit Color to fill with. Only lower byte of uint16_t is
used.
@brief Speed optimized vertical line drawing
@param x Line horizontal start point
@param y Line vertical start point
@param h Length of vertical line to be drawn, including first point
@param color 8-bit Color to fill with. Only lower byte of uint16_t is
used.
*/
/**************************************************************************/
void GFXcanvas8::drawFastVLine(int16_t x, int16_t y, int16_t h,
uint16_t color) {
if ((x < 0) || (x >= width()) || (y < 0) || (y >= height())) {
return;
}

if (y + h > height()) {
h = height() - y;
} else if (h < 0) {
// convert negative heights to their postive equivalent
if (h < 0) { // Convert negative heights to positive equivalent
h *= -1;
y -= h - 1;
if (y < 0) {
Expand All @@ -2232,6 +2246,19 @@ void GFXcanvas8::drawFastVLine(int16_t x, int16_t y, int16_t h,
}
}

// Edge rejection (no-draw if totally off canvas)
if ((x < 0) || (x >= width()) || (y >= height()) || ((y + h - 1) < 0)) {
return;
}

if (y < 0) { // Clip top
h += y;
y = 0;
}
if (y + h > height()) { // Clip bottom
h = height() - y;
}

if (getRotation() == 0) {
drawFastRawVLine(x, y, h, color);
} else if (getRotation() == 1) {
Expand All @@ -2256,24 +2283,18 @@ void GFXcanvas8::drawFastVLine(int16_t x, int16_t y, int16_t h,

/**************************************************************************/
/*!
@brief Speed optimized horizontal line drawing
@param x Line horizontal start point
@param y Line vertical start point
@param w length of horizontal line to be drawn, including first point
@param color 8-bit Color to fill with. Only lower byte of uint16_t is
used.
@brief Speed optimized horizontal line drawing
@param x Line horizontal start point
@param y Line vertical start point
@param w Length of horizontal line to be drawn, including 1st point
@param color 8-bit Color to fill with. Only lower byte of uint16_t is
used.
*/
/**************************************************************************/
void GFXcanvas8::drawFastHLine(int16_t x, int16_t y, int16_t w,
uint16_t color) {
if ((x < 0) || (x >= width()) || (y < 0) || (y >= height())) {
return;
}

if (x + w > width()) {
w = width() - x;
} else if (w < 0) {
// convert negative widths to their postive equivalent
if (w < 0) { // Convert negative widths to positive equivalent
w *= -1;
x -= w - 1;
if (x < 0) {
Expand All @@ -2282,6 +2303,19 @@ void GFXcanvas8::drawFastHLine(int16_t x, int16_t y, int16_t w,
}
}

// Edge rejection (no-draw if totally off canvas)
if ((y < 0) || (y >= height()) || (x >= width()) || ((x + w - 1) < 0)) {
return;
}

if (x < 0) { // Clip left
w += x;
x = 0;
}
if (x + w >= width()) { // Clip right
w = width() - x;
}

if (getRotation() == 0) {
drawFastRawHLine(x, y, w, color);
} else if (getRotation() == 1) {
Expand Down Expand Up @@ -2498,14 +2532,7 @@ void GFXcanvas16::byteSwap(void) {
/**************************************************************************/
void GFXcanvas16::drawFastVLine(int16_t x, int16_t y, int16_t h,
uint16_t color) {
if ((x < 0) || (x >= width()) || (y < 0) || (y >= height())) {
return;
}

if (y + h > height()) {
h = height() - y;
} else if (h < 0) {
// convert negative heights to their postive equivalent
if (h < 0) { // Convert negative heights to positive equivalent
h *= -1;
y -= h - 1;
if (y < 0) {
Expand All @@ -2514,6 +2541,19 @@ void GFXcanvas16::drawFastVLine(int16_t x, int16_t y, int16_t h,
}
}

// Edge rejection (no-draw if totally off canvas)
if ((x < 0) || (x >= width()) || (y >= height()) || ((y + h - 1) < 0)) {
return;
}

if (y < 0) { // Clip top
h += y;
y = 0;
}
if (y + h > height()) { // Clip bottom
h = height() - y;
}

if (getRotation() == 0) {
drawFastRawVLine(x, y, h, color);
} else if (getRotation() == 1) {
Expand All @@ -2538,23 +2578,16 @@ void GFXcanvas16::drawFastVLine(int16_t x, int16_t y, int16_t h,

/**************************************************************************/
/*!
@brief Speed optimized horizontal line drawing
@param x Line horizontal start point
@param y Line vertical start point
@param w length of horizontal line to be drawn, including first point
@param color color 16-bit 5-6-5 Color to draw line with
@brief Speed optimized horizontal line drawing
@param x Line horizontal start point
@param y Line vertical start point
@param w Length of horizontal line to be drawn, including 1st point
@param color Color 16-bit 5-6-5 Color to draw line with
*/
/**************************************************************************/
void GFXcanvas16::drawFastHLine(int16_t x, int16_t y, int16_t w,
uint16_t color) {
if ((x < 0) || (x >= width()) || (y < 0) || (y >= height())) {
return;
}

if (x + w > width()) {
w = width() - x;
} else if (w < 0) {
// convert negative widths to their postive equivalent
if (w < 0) { // Convert negative widths to positive equivalent
w *= -1;
x -= w - 1;
if (x < 0) {
Expand All @@ -2563,6 +2596,19 @@ void GFXcanvas16::drawFastHLine(int16_t x, int16_t y, int16_t w,
}
}

// Edge rejection (no-draw if totally off canvas)
if ((y < 0) || (y >= height()) || (x >= width()) || ((x + w - 1) < 0)) {
return;
}

if (x < 0) { // Clip left
w += x;
x = 0;
}
if (x + w >= width()) { // Clip right
w = width() - x;
}

if (getRotation() == 0) {
drawFastRawHLine(x, y, w, color);
} else if (getRotation() == 1) {
Expand Down
2 changes: 1 addition & 1 deletion library.properties
View file
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
name=Adafruit GFX Library
version=1.10.1
version=1.10.2
author=Adafruit
maintainer=Adafruit <[email protected]>
sentence=Adafruit GFX graphics core library, this is the 'core' class that all our other graphics libraries derive from.
Expand Down

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