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lcdDrawLine() speed improvement

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Tectu 2012-07-24 03:24:50 +02:00
parent 5f268adaaa
commit fd65a3c5b5
1 changed files with 48 additions and 40 deletions
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88
glcd/glcd.c
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@ -267,49 +267,57 @@ void lcdVerticalScroll(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1, uint1
}
void lcdDrawLine(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1, uint16_t color) {
int16_t dy, dx;
int16_t addx = 1, addy = 1;
int16_t P, diff;
// speed improvement if vertical or horizontal
if(x0 == x1) {
lcdFillArea(x0, y0, x0+1, y1, color);
} else if (y0 == y1) {
lcdFillArea(x0, y0, x1, y0+1, color);
int16_t i = 0;
dx = abs((int16_t)(x1 - x0));
dy = abs((int16_t)(y1 - y0));
if(x0 > x1)
addx = -1;
if(y0 > y1)
addy = -1;
if(dx >= dy) {
dy *= 2;
P = dy - dx;
diff = P - dx;
for(; i<=dx; ++i) {
lcdDrawPixel(x0, y0, color);
if(P < 0) {
P += dy;
x0 += addx;
} else {
P += diff;
x0 += addx;
y0 += addy;
}
}
} else {
dx *= 2;
P = dx - dy;
diff = P - dy;
int16_t dy, dx;
int16_t addx = 1, addy = 1;
int16_t P, diff;
for(; i<=dy; ++i) {
lcdDrawPixel(x0, y0, color);
if(P < 0) {
P += dx;
y0 += addy;
} else {
P += diff;
x0 += addx;
y0 += addy;
int16_t i = 0;
dx = abs((int16_t)(x1 - x0));
dy = abs((int16_t)(y1 - y0));
if(x0 > x1)
addx = -1;
if(y0 > y1)
addy = -1;
if(dx >= dy) {
dy *= 2;
P = dy - dx;
diff = P - dx;
for(; i<=dx; ++i) {
lcdDrawPixel(x0, y0, color);
if(P < 0) {
P += dy;
x0 += addx;
} else {
P += diff;
x0 += addx;
y0 += addy;
}
}
} else {
dx *= 2;
P = dx - dy;
diff = P - dy;
for(; i<=dy; ++i) {
lcdDrawPixel(x0, y0, color);
if(P < 0) {
P += dx;
y0 += addy;
} else {
P += diff;
x0 += addx;
y0 += addy;
}
}
}
}