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Added drawEllipse and fillEllipse functions (#477)

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* Added drawEllipse and fillEllipse functions

* Formatting fixes
This commit is contained in:
DS-Aditya-928
2025-09-14 08:28:20 -04:00
committed by GitHub
parent 21648a8299
commit 32da3d2094
2 changed files with 120 additions and 0 deletions
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Adafruit_GFX.cpp
+116
View File
@@ -345,6 +345,122 @@ void Adafruit_GFX::drawLine(int16_t x0, int16_t y0, int16_t x1, int16_t y1,
}
}
/**************************************************************************/
/*!
@brief Draw an ellipse outline
@param x0 Center-point x coordinate
@param y0 Center-point y coordinate
@param rw Horizontal radius of ellipse
@param rh Vertical radius of ellipse
@param color 16-bit 5-6-5 Color to draw with
*/
/**************************************************************************/
void Adafruit_GFX::drawEllipse(int16_t x0, int16_t y0, int16_t rw, int16_t rh,
uint16_t color) {
#if defined(ESP8266)
yield();
#endif
// Bresenham's ellipse algorithm
int16_t x = 0, y = rh;
int32_t rw2 = rw * rw, rh2 = rh * rh;
int32_t twoRw2 = 2 * rw2, twoRh2 = 2 * rh2;
int32_t decision = rh2 - (rw2 * rh) + (rw2 / 4);
startWrite();
// region 1
while ((twoRh2 * x) < (twoRw2 * y)) {
writePixel(x0 + x, y0 + y, color);
writePixel(x0 - x, y0 + y, color);
writePixel(x0 + x, y0 - y, color);
writePixel(x0 - x, y0 - y, color);
x++;
if (decision < 0) {
decision += rh2 + (twoRh2 * x);
} else {
decision += rh2 + (twoRh2 * x) - (twoRw2 * y);
y--;
}
}
// region 2
decision = ((rh2 * (2 * x + 1) * (2 * x + 1)) >> 2) +
(rw2 * (y - 1) * (y - 1)) - (rw2 * rh2);
while (y >= 0) {
writePixel(x0 + x, y0 + y, color);
writePixel(x0 - x, y0 + y, color);
writePixel(x0 + x, y0 - y, color);
writePixel(x0 - x, y0 - y, color);
y--;
if (decision > 0) {
decision += rw2 - (twoRw2 * y);
} else {
decision += rw2 + (twoRh2 * x) - (twoRw2 * y);
x++;
}
}
endWrite();
}
/**************************************************************************/
/*!
@brief Draw an ellipse with filled colour
@param x0 Center-point x coordinate
@param y0 Center-point y coordinate
@param rw Horizontal radius of ellipse
@param rh Vertical radius of ellipse
@param color 16-bit 5-6-5 Color to draw with
*/
/**************************************************************************/
void Adafruit_GFX::fillEllipse(int16_t x0, int16_t y0, int16_t rw, int16_t rh,
uint16_t color) {
#if defined(ESP8266)
yield();
#endif
// Bresenham's ellipse algorithm
int16_t x = 0, y = rh;
int32_t rw2 = rw * rw, rh2 = rh * rh;
int32_t twoRw2 = 2 * rw2, twoRh2 = 2 * rh2;
int32_t decision = rh2 - (rw2 * rh) + (rw2 / 4);
startWrite();
// region 1
while ((twoRh2 * x) < (twoRw2 * y)) {
drawFastHLine(x0 - x, y0 + y, 2 * x + 1, color);
drawFastHLine(x0 - x, y0 - y, 2 * x + 1, color);
x++;
if (decision < 0) {
decision += rh2 + (twoRh2 * x);
} else {
decision += rh2 + (twoRh2 * x) - (twoRw2 * y);
y--;
}
}
// region 2
decision = ((rh2 * (2 * x + 1) * (2 * x + 1)) >> 2) +
(rw2 * (y - 1) * (y - 1)) - (rw2 * rh2);
while (y >= 0) {
drawFastHLine(x0 - x, y0 + y, 2 * x + 1, color);
drawFastHLine(x0 - x, y0 - y, 2 * x + 1, color);
y--;
if (decision > 0) {
decision += rw2 - (twoRw2 * y);
} else {
decision += rw2 + (twoRh2 * x) - (twoRw2 * y);
x++;
}
}
endWrite();
}
/**************************************************************************/
/*!
@brief Draw a circle outline
Adafruit_GFX.h
+4
View File
@@ -73,6 +73,10 @@ public:
void fillCircle(int16_t x0, int16_t y0, int16_t r, uint16_t color);
void fillCircleHelper(int16_t x0, int16_t y0, int16_t r, uint8_t cornername,
int16_t delta, uint16_t color);
void drawEllipse(int16_t x0, int16_t y0, int16_t rw, int16_t rh,
uint16_t color);
void fillEllipse(int16_t x0, int16_t y0, int16_t rw, int16_t rh,
uint16_t color);
void drawTriangle(int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2,
int16_t y2, uint16_t color);
void fillTriangle(int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2,