/**
* \brief Get the pixel value at x,y
*
* \param x X coordinate of pixel
* \param y Y coordinate of pixel
* \return Non zero value if pixel is set.
*
* The following example will read the pixel value from x=10,y=10:
* \code
* pixelval = gfx_mono_ssd1306_get_pixel(10,10);
* \endcode
*/
uint8_t gfx_mono_ssd1306_get_pixel(gfx_coord_t x, gfx_coord_t y)
{
uint8_t page;
uint8_t pixel_mask;
if ((x > GFX_MONO_LCD_WIDTH - 1) || (y > GFX_MONO_LCD_HEIGHT - 1)) {
return 0;
}
page = y / GFX_MONO_LCD_PIXELS_PER_BYTE;
pixel_mask = (1 << (y - (page * 8)));
return gfx_mono_get_byte(page, x) & pixel_mask;
}
/**
* \brief Draw pixel to screen
*
* \param x X coordinate of the pixel
* \param y Y coordinate of the pixel
* \param color Pixel operation
*
* The following will set the pixel at x=10,y=10:
* \code
* gfx_mono_ssd1306_draw_pixel(10, 10, GFX_PIXEL_SET);
* \endcode
* The following example will clear the pixel at x=10,y=10:
* \code
* gfx_mono_ssd1306_draw_pixel(10, 10, GFX_PIXEL_CLR);
* \endcode
* And the following will toggle the pixel at x=10,y=10:
* \code
* gfx_mono_ssd1306_draw_pixel(10, 10, GFX_PIXEL_XOR);
* \endcode
*/
void gfx_mono_ssd1306_draw_pixel(gfx_coord_t x, gfx_coord_t y,
gfx_coord_t color)
{
uint8_t page;
uint8_t pixel_mask;
uint8_t pixel_value;
/* Discard pixels drawn outside the screen */
if ((x > GFX_MONO_LCD_WIDTH - 1) || (y > GFX_MONO_LCD_HEIGHT - 1)) {
return;
}
page = y / GFX_MONO_LCD_PIXELS_PER_BYTE;
pixel_mask = (1 << (y - (page * 8)));
/*
* Read the page containing the pixel in interest, then perform the
* requested action on this pixel before writing the page back to the
* display.
*/
pixel_value = gfx_mono_get_byte(page, x);
switch (color) {
case GFX_PIXEL_SET:
pixel_value |= pixel_mask;
break;
case GFX_PIXEL_CLR:
pixel_value &= ~pixel_mask;
break;
case GFX_PIXEL_XOR:
pixel_value ^= pixel_mask;
break;
default:
break;
}
gfx_mono_put_byte(page, x, pixel_value);
}
/**
* \brief Read/Modify/Write a byte in the framebuffer
*
* This function will read the byte from the framebuffer and
* do a mask operation on the byte according to the pixel operation selected
* by the color argument and the pixel mask provided.
*
* \param page Page address
* \param column Page offset (x coordinate)
* \param pixel_mask Mask for pixel operation
* \param color Pixel operation
*
* A small example that will XOR the first byte of the framebuffer with 0xAA
* \code
* gfx_mono_framebuffer_mask_byte(0,0,0xAA,GFX_PIXEL_XOR);
* \endcode
*/
void gfx_mono_framebuffer_mask_byte(gfx_coord_t page, gfx_coord_t column,
gfx_mono_color_t pixel_mask, gfx_mono_color_t color)
{
gfx_mono_color_t temp;
temp = gfx_mono_get_byte(page, column);
switch(color) {
case GFX_PIXEL_SET:
temp |= pixel_mask;
break;
case GFX_PIXEL_CLR:
temp &= ~pixel_mask;
break;
case GFX_PIXEL_XOR:
temp ^= pixel_mask;
break;
}
gfx_mono_put_byte(page, column, temp);
}
