complete fb variant demo

examples/fb_mode_test/main/main.c

@@ -2,17 +2,23 @@
  * Visual tests for framebuffer modes that are not commonly used by the high-level API.
  * Currently, includes 2 pixel per byte (ppB) with static origin color and 8ppB with static origin
  * color.
+ *
+ * After running this, you should see two identical test images, with a "ladder" of black triangles
+ * next to a black rectangle with a ladder of white triangles on it.
  */
 
 #include <esp_heap_caps.h>
 #include <esp_log.h>
 #include <esp_sleep.h>
 #include <esp_timer.h>
 #include <esp_types.h>
+#include <esp_assert.h>
 #include <freertos/FreeRTOS.h>
 #include <freertos/task.h>
 #include <inttypes.h>
+#include <stdint.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include <epdiy.h>
@@ -61,7 +67,7 @@ void draw_8bpp_triangles(int start_line, int start_column) {
 
     for (int align = 0; align < 16; align++) {
         for (int height = 0; height < 16; height++) {
-            for (int len = 0; len < height; len++) {
+            for (int len = 0; len <= height; len++) {
                 int line = (start_line + 16 * align + height);
                 int column = align + len;
                 uint8_t* line_address = framebuffer + (line_bytes * line);
@@ -71,8 +77,27 @@ void draw_8bpp_triangles(int start_line, int start_column) {
     }
 }
 
+/**
+ * Draw triangles at varying alignments into the framebuffer in 2ppB mode.
+ * start_line, start_column specify the start position.
+ * color specifies the color to draw in.
+ */
+void draw_2bpp_triangles(int start_line, int start_column, uint8_t color) {
+    int height = 16;
+
+    for (int align = 0; align < 16; align++) {
+        int x0 = start_column + align;
+        int y0 = start_line + height * align;
+        int x1 = x0;
+        int y1 = y0 + height - 1;
+        int x2 = x0 + height - 1;
+        int y2 = y0 + height - 1;
+
+        epd_fill_triangle(x0, y0, x1, y1, x2, y2, color, framebuffer);
+    }
+}
+
 void test_8ppB() {
-    clear();
     EpdRect area = epd_full_screen();
 
     // bytes in a line in 8ppB mode
@@ -105,18 +130,67 @@ void test_8ppB() {
     epd_poweroff();
 }
 
+void test_2ppB() {
+    EpdRect area = epd_full_screen();
+    int start_column = 500;
+    int start_line = 100;
+
+    // draw differently aligned black triangles to check for uniformity
+    draw_2bpp_triangles(start_line, start_column, 0);
+
+    int black_start_column = start_column + 60;
+
+    // draw a black area
+    EpdRect black_area = { .x = black_start_column, .y = 100, .width = 256, .height = 300 };
+    epd_fill_rect(black_area, 0, framebuffer);
+
+    // draw white triangles on the black background
+    draw_2bpp_triangles(start_line, black_start_column + 16, 255);
+
+    // Do not overdraw the 8ppB image
+    uint8_t* drawn_columns = malloc(epd_width() / 2);
+    assert(drawn_columns != NULL);
+    memset(drawn_columns, 0, epd_width() / 2);
+    memset(drawn_columns + start_column / 2, 255, (epd_width() - start_column) / 2);
+
+    // update the display. In the first update, white pixels are no-opps,
+    // in the second update, black pixels are no-ops.
+    enum EpdDrawMode mode;
+    epd_poweron();
+    mode = MODE_PACKING_2PPB | MODE_DU | PREVIOUSLY_WHITE;
+    checkError(
+        epd_draw_base(area, framebuffer, area, mode, 25, NULL, drawn_columns, &epdiy_ED047TC2)
+    );
+    mode = MODE_PACKING_2PPB | MODE_DU | PREVIOUSLY_BLACK;
+    checkError(
+        epd_draw_base(area, framebuffer, area, mode, 25, NULL, drawn_columns, &epdiy_ED047TC2)
+    );
+    epd_poweroff();
+
+    free(drawn_columns);
+}
+
 void app_main() {
     epd_init(&DEMO_BOARD, &ED060XC3, EPD_OPTIONS_DEFAULT);
+
     // Set VCOM for boards that allow to set this in software (in mV).
     // This will print an error if unsupported. In this case,
     // set VCOM using the hardware potentiometer and delete this line.
     epd_set_vcom(2100);
 
+    epd_set_lcd_pixel_clock_MHz(10);
+
     fb_size = epd_width() * epd_height() / 2;
     framebuffer = heap_caps_aligned_alloc(16, fb_size, MALLOC_CAP_SPIRAM);
 
+    clear();
+
     test_8ppB();
 
+    memset(framebuffer, 0xFF, fb_size);
+
+    test_2ppB();
+
     printf("going to sleep...\n");
     epd_deinit();
     esp_deep_sleep_start();