/**
* \brief Graph task
*
* This task runs in the background to draw a pseudo-random graph to a dedicated
* display buffer. If the user selects a different screen than the graph, it
* will continue to update even though it is not visible until the graph screen
* is selected again.
*
* \param params Parameters for the task. (Not used.)
*/
static void graph_task(void *params)
{
gfx_coord_t x, y, old_y;
uint8_t current_value;
EventBits_t event_bits;
const TickType_t ticks_to_wait = 10 / portTICK_PERIOD_MS;
x = 0;
current_value = graph_noise;
for(;;) {
/* Wait a maximum of 10ms for either bit 0 or bit 1 to be set within
the event group. Not clear the bits before exiting. */
event_bits = xEventGroupWaitBits(
event_group, /* The event group being tested. */
EVENT_DISPLAY_INIT | EVENT_DISPLAY_GRAPH, /* The bits within the event group to wait for. */
pdFALSE, /* Bit should not be cleared before returning. */
pdFALSE, /* Don't wait for both bits, either bit will do. */
ticks_to_wait);/* Wait a maximum of 10ms for either bit to be set. */
if((event_bits & EVENT_DISPLAY_INIT) ||
(event_bits & EVENT_DISPLAY_GRAPH)) {
oled1_set_led_state(&oled1, OLED1_LED1_ID, true);
// Compute new noise sample and value of current graph sample
graph_noise = (graph_noise * 173) + 1;
current_value = ((uint16_t)graph_noise + current_value) / 2;
xSemaphoreTake(display_mutex, portMAX_DELAY);
// Scale graph value so it fits within the canvas
y = CANVAS_GRAPH_Y_OFFSET
+ ((uint16_t)CANVAS_HEIGHT * current_value) / 256;
// Clear previous graph point..
gfx_mono_draw_vertical_line(x, CANVAS_GRAPH_Y_OFFSET, CANVAS_HEIGHT,
GFX_PIXEL_CLR);
// ..and draw a continuous graph using lines
if (x == 0) {
gfx_mono_draw_pixel(x, y, GFX_PIXEL_SET);
} else {
gfx_mono_draw_line(x - 1, old_y, x, y, GFX_PIXEL_SET);
}
xSemaphoreGive(display_mutex);
old_y = y;
if (++x >= CANVAS_WIDTH) {
x = 0;
}
oled1_set_led_state(&oled1, OLED1_LED1_ID, false);
}
vTaskDelay(GRAPH_TASK_DELAY);
}
}
/**
* \internal
* \brief Helper function that draws a character from a font in progmem
* to the display
*
* This function will first calculate the start offset in the font character
* data before iterating over the specific character data.
*
* Only pixels in the character that should be enabled are done so, the caller
* is required to prepare the drawing area before printing a character to it.
* This is done by the gfx_mono_draw_string() and
* gfx_mono_draw_progmem_string() functions.
*
* \param ch Character to be drawn
* \param x X coordinate on screen.
* \param y Y coordinate on screen.
* \param font Font to draw character in
*/
static void gfx_mono_draw_char_progmem(const char ch, const gfx_coord_t x,
const gfx_coord_t y, const struct font *font)
{
uint8_t PROGMEM_PTR_T glyph_data;
uint16_t glyph_data_offset;
uint8_t char_row_size;
uint8_t rows_left;
uint8_t i;
/* Sanity check on parameters, assert if font is NULL. */
Assert(font != NULL);
gfx_coord_t inc_x = x;
gfx_coord_t inc_y = y;
char_row_size = font->width / CONFIG_FONT_PIXELS_PER_BYTE;
if (font->width % CONFIG_FONT_PIXELS_PER_BYTE) {
char_row_size++;
}
glyph_data_offset = char_row_size * font->height *
((uint8_t)ch - font->first_char);
glyph_data = font->data.progmem + glyph_data_offset;
rows_left = font->height;
do {
uint8_t glyph_byte = 0;
uint8_t pixelsToDraw = font->width;
for (i = 0; i < pixelsToDraw; i++) {
if (i % CONFIG_FONT_PIXELS_PER_BYTE == 0) {
glyph_byte = PROGMEM_READ_BYTE(glyph_data);
glyph_data++;
}
if ((glyph_byte & 0x80)) {
gfx_mono_draw_pixel(inc_x, inc_y,
GFX_PIXEL_SET);
}
inc_x += 1;
glyph_byte <<= 1;
}
inc_y += 1;
inc_x = x;
rows_left--;
} while (rows_left > 0);
}
/**
* \brief Graph task
*
* This task runs in the background to draw a pseudo-random graph to a dedicated
* display buffer. If the user selects a different screen than the graph, it
* will continue to update even though it is not visible until the graph screen
* is selected again.
*
* \param params Parameters for the task. (Not used.)
*/
static void graph_task(void *params)
{
gfx_coord_t x, y, old_y;
uint8_t current_value;
x = 0;
current_value = graph_noise;
for(;;) {
oled1_set_led_state(&oled1, OLED1_LED1_ID, true);
// Compute new noise sample and value of current graph sample
graph_noise = (graph_noise * 173) + 1;
current_value = ((uint16_t)graph_noise + current_value) / 2;
xSemaphoreTake(display_mutex, portMAX_DELAY);
// Scale graph value so it fits within the canvas
y = CANVAS_GRAPH_Y_OFFSET
+ ((uint16_t)CANVAS_HEIGHT * current_value) / 256;
// Clear previous graph point..
gfx_mono_draw_vertical_line(x, CANVAS_GRAPH_Y_OFFSET, CANVAS_HEIGHT,
GFX_PIXEL_CLR);
// ..and draw a continuous graph using lines
if (x == 0) {
gfx_mono_draw_pixel(x, y, GFX_PIXEL_SET);
} else {
gfx_mono_draw_line(x - 1, old_y, x, y, GFX_PIXEL_SET);
}
xSemaphoreGive(display_mutex);
old_y = y;
if (++x >= CANVAS_WIDTH) {
x = 0;
}
oled1_set_led_state(&oled1, OLED1_LED1_ID, false);
vTaskDelay(GRAPH_TASK_DELAY);
}
}
/**
* \internal
* \brief Helper function that draws a character from a font in hugemem
* to the display
*
* This function will first calculate the start offset in the font character
* data before iterating over the specific character data.
*
* Only pixels in the character that should be enabled are done so, the caller
* is required to prepare the drawing area before printing a character to it.
* This is done by the gfx_mono_draw_string() and
* gfx_mono_draw_progmem_string() functions.
*
* \param ch Character to be drawn
* \param x X coordinate on screen.
* \param y Y coordinate on screen.
* \param font Font to draw character in
*/
static void gfx_mono_draw_char_hugemem(const char ch, const gfx_coord_t x,
const gfx_coord_t y, const struct font *font)
{
uint8_t i;
uint8_t char_row_size;
uint8_t glyph_size;
uint16_t glyph_data_offset;
uint8_t char_buff[EXTMEM_BUF_SIZE];
uint8_t buffer_pos;
uint8_t rows_left;
/* Sanity check on parameters, assert if font is NULL. */
Assert(font != NULL);
gfx_coord_t inc_x = x;
gfx_coord_t inc_y = y;
char_row_size = font->width / CONFIG_FONT_PIXELS_PER_BYTE;
if (font->width % CONFIG_FONT_PIXELS_PER_BYTE) {
char_row_size++;
}
glyph_size = char_row_size * font->height;
glyph_data_offset = glyph_size * ((uint8_t)ch - font->first_char);
buffer_pos = EXTMEM_BUF_SIZE;
rows_left = font->height;
do {
static uint8_t glyph_byte = 0;
uint8_t pixelsToDraw = font->width;
for (i = 0; i < pixelsToDraw; i++) {
if (i % CONFIG_FONT_PIXELS_PER_BYTE == 0) {
/* Read another byte from hugemem */
if (buffer_pos >= EXTMEM_BUF_SIZE) {
hugemem_ptr_t source
= font->data.hugemem;
source = (hugemem_ptr_t)
((uint32_t)source +
glyph_data_offset);
hugemem_read_block(char_buff, source,
EXTMEM_BUF_SIZE);
glyph_data_offset += EXTMEM_BUF_SIZE;
buffer_pos = 0;
}
glyph_byte = char_buff[buffer_pos];
buffer_pos++;
}
/* Draw bit of glyph to screen */
if ((glyph_byte & 0x80)) {
gfx_mono_draw_pixel(inc_x, inc_y,
GFX_PIXEL_SET);
}
inc_x += 1;
glyph_byte <<= 1;
}
inc_y += 1;
inc_x = x;
} while (--rows_left > 0);
}