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Add SSD1306_DrawLine

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Marián 2022-11-25 09:05:32 +01:00 committed by GitHub
parent cdff4b6d17
commit b7d0f13c92
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1 changed files with 70 additions and 8 deletions
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lib/ssd1306.c
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@ -102,25 +102,26 @@
const uint8_t INIT_SSD1306[] PROGMEM = {
18, // number of initializers
0, SSD1306_DISPLAY_OFF, // 0xAE = Set Display OFF
1, SSD1306_SET_MUX_RATIO, 0x3F, // 0xA8
1, SSD1306_SET_MUX_RATIO, 0x3F, // 0xA8 - 64MUX
1, SSD1306_MEMORY_ADDR_MODE, 0x00, // 0x20 = Set Memory Addressing Mode
// 0x00 - Horizontal Addressing Mode
// 0x01 - Vertical Addressing Mode
// 0x02 - Page Addressing Mode (RESET)
2, SSD1306_SET_COLUMN_ADDR, START_COLUMN_ADDR, END_COLUMN_ADDR, // 0x21 = Set Column Address
2, SSD1306_SET_PAGE_ADDR, START_PAGE_ADDR, END_PAGE_ADDR, // 0x22 = Set Page Address
2, SSD1306_SET_COLUMN_ADDR, START_COLUMN_ADDR, END_COLUMN_ADDR, // 0x21 = Set Column Address, 0 - 127
2, SSD1306_SET_PAGE_ADDR, START_PAGE_ADDR, END_PAGE_ADDR, // 0x22 = Set Page Address, 0 - 7
0, SSD1306_SET_START_LINE, // 0x40
1, SSD1306_DISPLAY_OFFSET, 0x00, // 0xD3
0, SSD1306_SEG_REMAP_OP, // 0xA0 / remap 0xA1
0, SSD1306_COM_SCAN_DIR_OP, // 0xC0 / remap 0xC8
1, SSD1306_COM_PIN_CONF, 0x12, // 0xDA
1, SSD1306_SET_CONTRAST, 0x7F, // 0x81
1, SSD1306_COM_PIN_CONF, 0x12, // 0xDA, 0x12 - Disable COM Left/Right remap, Alternative COM pin configuration
1, SSD1306_SET_CONTRAST, 0x7F, // 0x81, 0x7F - reset value (max 0xFF)
0, SSD1306_DIS_ENT_DISP_ON, // 0xA4
0, SSD1306_DIS_NORMAL, // 0xA6
1, SSD1306_SET_OSC_FREQ, 0x80, // 0xD5
1, SSD1306_SET_PRECHARGE, 0xc2, // 0xD9, 1st Period = higher value less blinking
1, SSD1306_SET_OSC_FREQ, 0x80, // 0xD5, 0x80 => D=1; DCLK = Fosc / D <=> DCLK = Fosc
1, SSD1306_SET_PRECHARGE, 0xc2, // 0xD9, higher value less blinking
// 0xC2, 1st phase = 2 DCLK, 2nd phase = 13 DCLK
1, SSD1306_VCOM_DESELECT, 0x20, // Set V COMH Deselect, reset value 0x22 = 0,77xUcc
1, SSD1306_SET_CHAR_REG, 0x14, // 0x8D
1, SSD1306_SET_CHAR_REG, 0x14, // 0x8D, Enable charge pump during display on
0, SSD1306_DISPLAY_ON // 0xAF = Set Display ON
};
@ -556,3 +557,64 @@ uint8_t SSD1306_DrawPixel (uint8_t x, uint8_t y)
return SSD1306_SUCCESS; // success
}
/**
* @desc Draw line by Bresenham algoritm
*
* @param uint8_t x start position / 0 <= cols <= MAX_X-1
* @param uint8_t x end position / 0 <= cols <= MAX_X-1
* @param uint8_t y start position / 0 <= rows <= MAX_Y-1
* @param uint8_t y end position / 0 <= rows <= MAX_Y-1
*
* @return uint8_t
*/
uint8_t SSD1306_DrawLine (uint8_t x1, uint8_t x2, uint8_t y1, uint8_t y2)
{
int16_t D; // determinant
int16_t delta_x, delta_y; // deltas
int16_t trace_x = 1, trace_y = 1; // steps
delta_x = x2 - x1; // delta x
delta_y = y2 - y1; // delta y
if (delta_x < 0) { // check if x2 > x1
delta_x = -delta_x; // negate delta x
trace_x = -trace_x; // negate step x
}
if (delta_y < 0) { // check if y2 > y1
delta_y = -delta_y; // negate delta y
trace_y = -trace_y; // negate step y
}
// condition for m < 1 (dy < dx)
// -------------------------------------------------------------------------------------
if (delta_y < delta_x) { //
D = (delta_y << 1) - delta_x; // calculate determinant
SSD1306_DrawPixel (x1, y1); // draw first pixel
while (x1 != x2) { // check if x1 equal x2
x1 += trace_x; // update x1
if (D >= 0) { // positive?
y1 += trace_y; // update y1
D -= 2*delta_x; // update determinant
}
D += 2*delta_y; // update deteminant
SSD1306_DrawPixel (x1, y1); // draw next pixel
}
// condition for m >= 1 (dy >= dx)
// -------------------------------------------------------------------------------------
} else {
D = delta_y - (delta_x << 1); // calculate determinant
SSD1306_DrawPixel (x1, y1); // draw first pixel
while (y1 != y2) { // check if y2 equal y1
y1 += trace_y; // update y1
if (D <= 0) { // positive?
x1 += trace_x; // update y1
D += 2*delta_y; // update determinant
}
D -= 2*delta_x; // update deteminant
SSD1306_DrawPixel (x1, y1); // draw next pixel
}
}
return SSD1306_SUCCESS; // success return
}