[Keymap] Add onekey keymap for OLED testing (#10380)

* Add onekey keymap for OLED testing

* Add license header

3 files changed, 477 insertions, 0 deletions

diff --git a/keyboards/handwired/onekey/keymaps/oled/keymap.c b/keyboards/handwired/onekey/keymaps/oled/keymap.c
new file mode 100644
index 0000000000..b6e66ace74
--- /dev/null
+++ b/keyboards/handwired/onekey/keymaps/oled/keymap.c
@@ -0,0 +1,452 @@
+/* Copyright 2020 Sergey Vlasov <sigprof@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include QMK_KEYBOARD_H
+
+enum tap_dances {
+    TD_OLED,
+};
+
+enum oled_test_modes {
+    // Modes between TEST_FIRST and TEST_LAST (inclusive) can be switched with a keypress.
+    TEST_FIRST,
+    TEST_LOGO = TEST_FIRST,
+    TEST_CHARACTERS,
+    TEST_SLOW_UPDATE,
+    TEST_ALL_ON,
+    TEST_FRAME,
+    TEST_ALL_OFF,
+    TEST_FILL_HORZ_0,
+    TEST_FILL_HORZ_1,
+    TEST_FILL_VERT_0,
+    TEST_FILL_VERT_1,
+    TEST_FILL_CHECKERBOARD_1,
+    TEST_FILL_CHECKERBOARD_2,
+    TEST_FILL_CHECKERBOARD_4,
+    TEST_LAST = TEST_FILL_CHECKERBOARD_4,
+
+    // Special modes which are not reachable normally.
+    TEST_DRAW_ALWAYS_ON,
+    TEST_DRAW_ALWAYS_OFF,
+};
+
+static enum oled_test_modes test_mode = TEST_FIRST;
+
+static oled_rotation_t rotation = OLED_ROTATION_0;
+
+static bool     scrolling;
+static uint8_t  scrolling_speed;
+static bool     need_update = true;
+static bool     draw_always;
+static bool     update_speed_test;
+static uint32_t update_speed_start_timer;
+static uint16_t update_speed_count;
+static bool     restart_test;
+
+static void stop_scrolling(void) {
+    if (scrolling) {
+        oled_scroll_off();
+        scrolling = false;
+    }
+}
+
+static void dance_oled_finished(qk_tap_dance_state_t *state, void *user_data) {
+    switch (state->count) {
+        case 1:
+            if (state->pressed) {
+                // single hold - step through rotations
+                switch (rotation) {
+                    case OLED_ROTATION_0:
+                        rotation = OLED_ROTATION_90;
+                        break;
+                    case OLED_ROTATION_90:
+                        rotation = OLED_ROTATION_180;
+                        break;
+                    case OLED_ROTATION_180:
+                        rotation = OLED_ROTATION_270;
+                        break;
+                    default:
+                        rotation = OLED_ROTATION_0;
+                        break;
+                }
+                stop_scrolling();
+                oled_init(rotation);
+            } else {
+                // single tap - step through test modes
+                if (test_mode < TEST_LAST) {
+                    ++test_mode;
+                } else {
+                    test_mode = TEST_FIRST;
+                }
+                stop_scrolling();
+                oled_clear();
+            }
+            restart_test = true;
+            need_update  = true;
+            break;
+
+        case 2:
+            if (state->pressed) {
+                // tap + hold - change scrolling speed
+                scrolling_speed = (scrolling_speed + 1) % 8;
+                stop_scrolling();
+                oled_scroll_set_speed(scrolling_speed);
+                // Cannot reactivate scrolling here, because oled_scroll_off()
+                // marks the whole display as dirty, and oled_scroll_left()
+                // silently does nothing if either the display is dirty or
+                // scrolling is already active.
+            } else {
+                // double tap - toggle scrolling
+                if (!scrolling) {
+                    scrolling = true;
+                    oled_scroll_left();
+                } else {
+                    scrolling = false;
+                    oled_scroll_off();
+                }
+            }
+            need_update = true;
+            break;
+
+        case 3:
+            if (state->pressed) {
+                // double tap + hold - toggle `draw_always`
+                draw_always = !draw_always;
+                if (draw_always) {
+                    test_mode = TEST_DRAW_ALWAYS_ON;
+                } else {
+                    test_mode = TEST_DRAW_ALWAYS_OFF;
+                }
+                stop_scrolling();
+                oled_clear();
+                restart_test = true;
+                need_update  = true;
+            } else {
+                // triple tap - toggle update speed test
+                update_speed_test = !update_speed_test;
+                if (update_speed_test) {
+                    stop_scrolling();
+                    update_speed_start_timer = timer_read32();
+                    update_speed_count       = 0;
+                }
+            }
+            break;
+        default:
+            break;
+    }
+}
+
+qk_tap_dance_action_t tap_dance_actions[] = {[TD_OLED] = ACTION_TAP_DANCE_FN(dance_oled_finished)};
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {LAYOUT_ortho_1x1(TD(TD_OLED))};
+
+// `bool oled_is_dirty(void)` does not exist at the moment
+extern OLED_BLOCK_TYPE oled_dirty;
+
+static inline uint8_t pixel_width(void) {
+    if (!(rotation & OLED_ROTATION_90)) {
+        return OLED_DISPLAY_WIDTH;
+    }
+    return OLED_DISPLAY_HEIGHT;
+}
+
+static inline uint8_t pixel_height(void) {
+    if (!(rotation & OLED_ROTATION_90)) {
+        return OLED_DISPLAY_HEIGHT;
+    }
+    return OLED_DISPLAY_WIDTH;
+}
+
+// Draw the QMK logo at the top left corner, clipping if it does not fit.
+static void test_logo(void) {
+    uint8_t lines = oled_max_lines();
+    if (lines > 3) {
+        lines = 3;
+    }
+    uint8_t chars = oled_max_chars();
+    if (chars > 21) {
+        chars = 21;
+    }
+    for (uint8_t row = 0; row < lines; ++row) {
+        oled_set_cursor(0, row);
+        for (uint8_t col = 0; col < chars; ++col) {
+            oled_write_char(0x80 + 0x20 * row + col, false);
+        }
+    }
+}
+
+static const PROGMEM char fill_ff[OLED_MATRIX_SIZE] = {[0 ... OLED_MATRIX_SIZE - 1] = 0xff};
+
+// Fill the whole screen with a pattern made from two bytes alternating after the specified number of repeats.
+static void test_fill(uint8_t byte0, uint8_t byte1, uint8_t repeats) {
+    uint8_t  width = pixel_width();
+    uint8_t  lines = oled_max_lines();
+    uint16_t index = 0;
+    for (uint8_t row = 0; row < lines; ++row) {
+        for (uint8_t col = 0; col < width; ++col) {
+            uint8_t byte = ((col / repeats) % 2) ? byte1 : byte0;
+            oled_write_raw_byte(byte, index++);
+        }
+    }
+}
+
+// Draw a frame at the edges of the OLED screen.
+static void test_frame(void) {
+    uint8_t width  = pixel_width();
+    uint8_t height = pixel_height();
+    for (uint8_t x = 0; x < width; ++x) {
+        oled_write_pixel(x, 0, true);
+        oled_write_pixel(x, height - 1, true);
+    }
+    for (uint8_t y = 1; y < height - 1; ++y) {
+        oled_write_pixel(0, y, true);
+        oled_write_pixel(width - 1, y, true);
+    }
+}
+
+// Use all 94 visible ASCII characters for testing.
+#define TEST_CHAR_COUNT ('~' - '!' + 1)
+
+static char get_test_char(uint8_t char_index) { return char_index + '!'; }
+
+// Fill the whole screen with distinct characters (if the display is large enough to show more than 94 characters
+// at once, the sequence is repeated the second time with inverted characters).
+static void test_characters(void) {
+    uint8_t cols       = oled_max_chars();
+    uint8_t rows       = oled_max_lines();
+    bool    invert     = false;
+    uint8_t char_index = 0;
+    for (uint8_t row = 0; row < rows; ++row) {
+        for (uint8_t col = 0; col < cols; ++col) {
+            oled_write_char(get_test_char(char_index), invert);
+            if (++char_index >= TEST_CHAR_COUNT) {
+                char_index = 0;
+                invert     = !invert;
+            }
+        }
+    }
+}
+
+// Test screen updating after drawing a single character or pixel.
+void test_slow_update(void) {
+    static uint8_t  phase, x, y, char_index, first_char;
+    static uint16_t timer;
+    static uint16_t delay = 500;
+
+    if (restart_test) {
+        // Initialize all state variables before starting the test.
+        restart_test = false;
+        phase        = 0;
+        x            = 0;
+        y            = 0;
+        char_index   = 0;
+        first_char   = 0;
+        delay        = 500;
+    } else {
+        // Wait for the specified time between steps.
+        if (timer_elapsed(timer) < delay) {
+            return;
+        }
+    }
+
+    timer = timer_read();
+    switch (phase) {
+        case 0:
+            // Phase 0: fill the whole screen with mostly distinct characters, one character at a time.  Here the
+            // inversion trick is not used, so that the frame which is drawn in subsequent phases would not be
+            // overlapped by the inverted character background.
+            oled_set_cursor(x, y);
+            oled_write_char(get_test_char(char_index), false);
+            if (++char_index >= TEST_CHAR_COUNT) {
+                char_index = 0;
+            }
+            if (++x >= oled_max_chars()) {
+                x = 0;
+                if (++y >= oled_max_lines()) {
+                    // The whole screen was filled - start the next phase.
+                    ++phase;
+                    x = y = 0;
+                }
+            }
+            delay = 250;
+            break;
+
+        case 1:
+            // Phase 1: draw a line along the left edge of the screen, one pixel at a time.
+            oled_write_pixel(x, y, true);
+            if (y < pixel_height() - 1) {
+                ++y;
+            } else {
+                // The bottom left corner is reached - start the next phase.
+                ++phase;
+                ++x;
+            }
+            delay = 50;
+            break;
+
+        case 2:
+            // Phase 2: draw a line along the bottom edge of the screen, one pixel at a time.
+            oled_write_pixel(x, y, true);
+            if (x < pixel_width() - 1) {
+                ++x;
+            } else {
+                // The bottom right corner was reached - start the next phase.
+                ++phase;
+                --y;
+            }
+            delay = 50;
+            break;
+
+        case 3:
+            // Phase 3: draw a line along the right edge of the screen, one pixel at a time.
+            oled_write_pixel(x, y, true);
+            if (y > 0) {
+                --y;
+            } else {
+                // The top right corner was reached - start the next phase.
+                ++phase;
+                --x;
+            }
+            delay = 50;
+            break;
+
+        case 4:
+            // Phase 4: draw a line along the top edge of the screen, one pixel at a time.
+            oled_write_pixel(x, y, true);
+            if (x > 0) {
+                --x;
+            } else {
+                // The top left corner was reached - start the next phase.
+                ++phase;
+            }
+            delay = 50;
+            break;
+
+        default:
+            // Restart from phase 0, but change the first character of the sequence to make screen updates visible.
+            if (++first_char >= TEST_CHAR_COUNT) {
+                first_char = 0;
+            }
+            phase      = 0;
+            x          = 0;
+            y          = 0;
+            char_index = first_char;
+            delay      = 500;
+            break;
+    }
+}
+
+oled_rotation_t oled_init_user(oled_rotation_t rotation) {
+    oled_scroll_set_area(0, 0);
+    oled_scroll_set_speed(scrolling_speed);
+    return rotation;
+}
+
+void oled_task_user(void) {
+    if (update_speed_test) {
+        // Speed test mode - wait for screen update completion.
+        if (!oled_dirty) {
+            // Update statistics and send the measurement result to the console.
+            update_speed_count++;
+            if (update_speed_count % 256 == 0) {
+                uprintf("OLED: %u updates, %lu ms\n", update_speed_count, timer_elapsed32(update_speed_start_timer));
+            }
+
+            // Toggle between the "all on" and "all off" states and trigger the screen update again.
+            if (test_mode == TEST_ALL_ON) {
+                test_mode = TEST_ALL_OFF;
+            } else {
+                test_mode = TEST_ALL_ON;
+            }
+            need_update = true;
+        }
+    }
+
+    // The sample implementation of oled_task_user() in the documentation redraws the image after every call, relying on
+    // the fact that drawing functions check whether the output actually changes anything in the image, and set dirty
+    // bits only when something has actually changed.  However, redrawing the image only when some of the underlying
+    // data has changed is more efficient.  Make it possible to test both modes here.
+    if (!draw_always || update_speed_test) {
+        // Draw the image only when the `need_update` flag is set, except for the "slow update" test.
+        // This mode is also forced when the screen update speed test is performed.
+        if (!need_update) {
+            if (test_mode != TEST_SLOW_UPDATE) {
+                return;
+            }
+        }
+        need_update = false;
+    }
+
+    switch (test_mode) {
+        case TEST_LOGO:
+            test_logo();
+            break;
+        case TEST_CHARACTERS:
+            test_characters();
+            break;
+        case TEST_SLOW_UPDATE:
+            test_slow_update();
+            break;
+        case TEST_ALL_ON:
+            oled_write_raw_P(fill_ff, sizeof(fill_ff));
+            break;
+        case TEST_FRAME:
+            test_frame();
+            break;
+        case TEST_ALL_OFF:
+            // `oled_clear()` is faster, but cannot be used with `draw_always`, because it does not check the previous
+            // content of the buffer and always marks the whole buffer as dirty.
+            if (update_speed_test) {
+                oled_clear();
+            } else {
+                test_fill(0x00, 0x00, 1);
+            }
+            break;
+        case TEST_FILL_HORZ_0:
+            test_fill(0x55, 0x55, 1);
+            break;
+        case TEST_FILL_HORZ_1:
+            test_fill(0xaa, 0xaa, 1);
+            break;
+        case TEST_FILL_VERT_0:
+            test_fill(0xff, 0x00, 1);
+            break;
+        case TEST_FILL_VERT_1:
+            test_fill(0x00, 0xff, 1);
+            break;
+        case TEST_FILL_CHECKERBOARD_1:
+            test_fill(0x55, 0xaa, 1);
+            break;
+        case TEST_FILL_CHECKERBOARD_2:
+            test_fill(0x33, 0xcc, 2);
+            break;
+        case TEST_FILL_CHECKERBOARD_4:
+            test_fill(0x0f, 0xf0, 4);
+            break;
+
+        case TEST_DRAW_ALWAYS_ON:
+            oled_write_P(PSTR("Draw Always"), false);
+            break;
+        case TEST_DRAW_ALWAYS_OFF:
+            oled_write_P(PSTR("Draw Once"), false);
+            break;
+    }
+}
+
+void keyboard_post_init_user(void) {
+    // Console messages are used for update speed test results
+    debug_enable = true;
+}
diff --git a/keyboards/handwired/onekey/keymaps/oled/readme.md b/keyboards/handwired/onekey/keymaps/oled/readme.md
new file mode 100644
index 0000000000..380b3eb522
--- /dev/null
+++ b/keyboards/handwired/onekey/keymaps/oled/readme.md
@@ -0,0 +1,23 @@
+# OLED tester
+
+Available commands using a single key:
+- Single tap: Switch to the next test pattern.
+- Single hold: Switch to the next orientation (note that 90° and 270° orientations may not work correctly with some displays).
+- Double tap: Toggle horizontal scrolling of the top row.  Note that this scrolling is implemented by the controller and has major limitations: it works only with SSD1306-based displays, blocks all display updates, may not work correctly if the display width is less than 128 pixels, and does not handle 90°/270° rotation properly.
+- Tap and hold: Change scrolling speed (because of controller limitations, scrolling needs to be started again manually using a double tap).
+- Triple tap: Start or stop the update speed test.  This test repeatedly fills the display with all-on and all-off pixels, measures the time required for updating the display, and prints the measured values to the HID console every 256th refresh.
+- Double tap and hold: Switch between the “draw once” (default) and “draw always” modes.  The “draw always” mode means that `oled_task_user()` redraws the whole picture completely every time it is called; the example code in the OLED feature documentation is written in this style.  Testing the “draw always” mode can uncover bugs in the implementation of drawing functions (they must not set the dirty mark if the buffer content is not actually changed).
+
+Available test patterns:
+- QMK logo (clipped to fit on the display).
+- Fill the whole screen with as much unique characters as possible (all 94 printable ASCII characters are used, and if the display has more character positions available, the same characters are printed again, but inverted).
+- “Slow update” test — instead of updating the whole screen at once, draw things piece by piece to uncover display update bugs.  The drawing sequence used by this test:
+  - Fill the whole screen with printable ASCII characters (similar to the previous test, but characters are drawn one by one with 250 ms intervals between them, and inverted characters are not used to avoid obscuring the next phases).
+  - Draw a frame along the screen edges, starting from the top left corner and going down along the left edge, then along the bottom, right and top edges, with 50 ms delay after every pixel.
+  - Repeat the same sequence again, but with the character sequence shifted by 1 character (so that the updates would be visible).
+- All pixels on.
+- Pixels at the edges of the screen on.
+- All pixels off.
+- Horizontal on/off 1px lines (two variants - starting from on or off state).
+- Vertical on/off 1px lines (two variants - starting from on or off state).
+- Checkerboard pattern (three variants - 1×1, 2×2, 4×4 pixels).
diff --git a/keyboards/handwired/onekey/keymaps/oled/rules.mk b/keyboards/handwired/onekey/keymaps/oled/rules.mk
new file mode 100644
index 0000000000..2ef0a8d04f
--- /dev/null
+++ b/keyboards/handwired/onekey/keymaps/oled/rules.mk
@@ -0,0 +1,2 @@
+OLED_DRIVER_ENABLE = yes
+TAP_DANCE_ENABLE = yes