Gui: Direct Draw API (#2215)

* Furi: allow on-fly thread priority change. Gui: Direct Draw API. DirectDraw debug app.
* Gui: drop input in direct draw
* Furi: handle priority change for starting threads
* DirectDraw: rollback to FreeRTOS primitives for priority change

applications/debug/direct_draw/application.fam

@@ -0,0 +1,10 @@
+App(
+    appid="direct_draw",
+    name="Direct Draw",
+    apptype=FlipperAppType.DEBUG,
+    entry_point="direct_draw_app",
+    requires=["gui", "input"],
+    stack_size=2 * 1024,
+    order=70,
+    fap_category="Debug",
+)

applications/debug/direct_draw/direct_draw.c

@@ -0,0 +1,112 @@
+#include <furi.h>
+#include <gui/gui.h>
+#include <gui/canvas_i.h>
+#include <input/input.h>
+
+#define BUFFER_SIZE (32U)
+
+typedef struct {
+    FuriPubSub* input;
+    FuriPubSubSubscription* input_subscription;
+    Gui* gui;
+    Canvas* canvas;
+    bool stop;
+    uint32_t counter;
+} DirectDraw;
+
+static void gui_input_events_callback(const void* value, void* ctx) {
+    furi_assert(value);
+    furi_assert(ctx);
+
+    DirectDraw* instance = ctx;
+    const InputEvent* event = value;
+
+    if(event->key == InputKeyBack && event->type == InputTypeShort) {
+        instance->stop = true;
+    }
+}
+
+static DirectDraw* direct_draw_alloc() {
+    DirectDraw* instance = malloc(sizeof(DirectDraw));
+
+    instance->input = furi_record_open(RECORD_INPUT_EVENTS);
+    instance->gui = furi_record_open(RECORD_GUI);
+    instance->canvas = gui_direct_draw_acquire(instance->gui);
+
+    instance->input_subscription =
+        furi_pubsub_subscribe(instance->input, gui_input_events_callback, instance);
+
+    return instance;
+}
+
+static void direct_draw_free(DirectDraw* instance) {
+    furi_pubsub_unsubscribe(instance->input, instance->input_subscription);
+
+    instance->canvas = NULL;
+    gui_direct_draw_release(instance->gui);
+    furi_record_close(RECORD_GUI);
+    furi_record_close(RECORD_INPUT_EVENTS);
+}
+
+static void direct_draw_block(Canvas* canvas, uint32_t size, uint32_t counter) {
+    size += 16;
+    uint8_t width = canvas_width(canvas) - size;
+    uint8_t height = canvas_height(canvas) - size;
+
+    uint8_t x = counter % width;
+    if((counter / width) % 2) {
+        x = width - x;
+    }
+
+    uint8_t y = counter % height;
+    if((counter / height) % 2) {
+        y = height - y;
+    }
+
+    canvas_draw_box(canvas, x, y, size, size);
+}
+
+static void direct_draw_run(DirectDraw* instance) {
+    size_t start = DWT->CYCCNT;
+    size_t counter = 0;
+    float fps = 0;
+
+    vTaskPrioritySet(furi_thread_get_current_id(), FuriThreadPriorityIdle);
+
+    do {
+        size_t elapsed = DWT->CYCCNT - start;
+        char buffer[BUFFER_SIZE] = {0};
+
+        if(elapsed >= 64000000) {
+            fps = (float)counter / ((float)elapsed / 64000000.0f);
+
+            start = DWT->CYCCNT;
+            counter = 0;
+        }
+        snprintf(buffer, BUFFER_SIZE, "FPS: %.1f", (double)fps);
+
+        canvas_reset(instance->canvas);
+        canvas_set_color(instance->canvas, ColorXOR);
+        direct_draw_block(instance->canvas, instance->counter % 16, instance->counter);
+        direct_draw_block(instance->canvas, instance->counter * 2 % 16, instance->counter * 2);
+        direct_draw_block(instance->canvas, instance->counter * 3 % 16, instance->counter * 3);
+        direct_draw_block(instance->canvas, instance->counter * 4 % 16, instance->counter * 4);
+        direct_draw_block(instance->canvas, instance->counter * 5 % 16, instance->counter * 5);
+        canvas_draw_str(instance->canvas, 10, 10, buffer);
+        canvas_commit(instance->canvas);
+
+        counter++;
+        instance->counter++;
+        furi_thread_yield();
+    } while(!instance->stop);
+}
+
+int32_t direct_draw_app(void* p) {
+    UNUSED(p);
+
+    DirectDraw* instance = direct_draw_alloc();
+    direct_draw_run(instance);
+    direct_draw_free(instance);
+
+    return 0;
+}