void ssd1306_DrawFilledCircle(int16_t x0, int16_t y0, int16_t r, SSD1306_COLOR c) {
int16_t f = 1 - r;
int16_t ddF_x = 1;
int16_t ddF_y = -2 * r;
int16_t x = 0;
int16_t y = r;
ssd1306_DrawPixel(x0, y0 + r, c);
ssd1306_DrawPixel(x0, y0 - r, c);
ssd1306_DrawPixel(x0 + r, y0, c);
ssd1306_DrawPixel(x0 - r, y0, c);
ssd1306_DrawLine(x0 - r, y0, x0 + r, y0, c);
while (x < y) {
if (f >= 0) {
y--;
ddF_y += 2;
f += ddF_y;
}
x++;
ddF_x += 2;
f += ddF_x;
ssd1306_DrawLine(x0 - x, y0 + y, x0 + x, y0 + y, c);
ssd1306_DrawLine(x0 + x, y0 - y, x0 - x, y0 - y, c);
ssd1306_DrawLine(x0 + y, y0 + x, x0 - y, y0 + x, c);
ssd1306_DrawLine(x0 + y, y0 - x, x0 - y, y0 - x, c);
}
}
//
// Draw 1 char to the screen buffer
// ch => char om weg te schrijven
// Font => Font waarmee we gaan schrijven
// color => Black or White
//
char ssd1306_WriteChar(char ch, FontDef Font, SSD1306_COLOR color)
{
uint32_t i, b, j;
// Check remaining space on current line
if (SSD1306_WIDTH <= (SSD1306.CurrentX + Font.FontWidth) ||
SSD1306_HEIGHT <= (SSD1306.CurrentY + Font.FontHeight))
{
// Not enough space on current line
return 0;
}
// Use the font to write
for (i = 0; i < Font.FontHeight; i++)
{
b = Font.data[(ch - 32) * Font.FontHeight + i];
for (j = 0; j < Font.FontWidth; j++)
{
if ((b << j) & 0x8000)
{
ssd1306_DrawPixel(SSD1306.CurrentX + j, (SSD1306.CurrentY + i), (SSD1306_COLOR) color);
}
else
{
ssd1306_DrawPixel(SSD1306.CurrentX + j, (SSD1306.CurrentY + i), (SSD1306_COLOR)!color);
}
}
}
// The current space is now taken
SSD1306.CurrentX += Font.FontWidth;
// Return written char for validation
return ch;
}
void ssd1306_DrawLine(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1, SSD1306_COLOR c) {
int16_t dx, dy, sx, sy, err, e2, i, tmp;
/* Check for overflow */
if (x0 >= SSD1306_WIDTH) {
x0 = SSD1306_WIDTH - 1;
}
if (x1 >= SSD1306_WIDTH) {
x1 = SSD1306_WIDTH - 1;
}
if (y0 >= SSD1306_HEIGHT) {
y0 = SSD1306_HEIGHT - 1;
}
if (y1 >= SSD1306_HEIGHT) {
y1 = SSD1306_HEIGHT - 1;
}
dx = (x0 < x1) ? (x1 - x0) : (x0 - x1);
dy = (y0 < y1) ? (y1 - y0) : (y0 - y1);
sx = (x0 < x1) ? 1 : -1;
sy = (y0 < y1) ? 1 : -1;
err = ((dx > dy) ? dx : -dy) / 2;
if (dx == 0) {
if (y1 < y0) {
tmp = y1;
y1 = y0;
y0 = tmp;
}
if (x1 < x0) {
tmp = x1;
x1 = x0;
x0 = tmp;
}
/* Vertical line */
for (i = y0; i <= y1; i++) {
ssd1306_DrawPixel(x0, i, c);
}
/* Return from function */
return;
}
if (dy == 0) {
if (y1 < y0) {
tmp = y1;
y1 = y0;
y0 = tmp;
}
if (x1 < x0) {
tmp = x1;
x1 = x0;
x0 = tmp;
}
/* Horizontal line */
for (i = x0; i <= x1; i++) {
ssd1306_DrawPixel(i, y0, c);
}
/* Return from function */
return;
}
while (1) {
ssd1306_DrawPixel(x0, y0, c);
if (x0 == x1 && y0 == y1) {
break;
}
e2 = err;
if (e2 > -dx) {
err -= dy;
x0 += sx;
}
if (e2 < dy) {
err += dx;
y0 += sy;
}
}
}
