Update pong; change usb string descriptors

programs/pong/src/main.cpp

@@ -1,5 +1,6 @@
 #include "devicelib.h"
 
+#include <cmath>
 #include <hardware/clocks.h>
 #include <pico/bootrom.h>
 #include <tusb.h>
@@ -20,10 +21,14 @@ void draw_rectangle(float x, float y, float w, float h, uint8_t r, uint8_t g,
   int hi = h;
   display.set_update_area(x - w / 2, y - h / 2, wi, hi);
 
+  const uint8_t buf[24] = {
+    r, g, b, r, g, b, r, g, b, r, g, b, r, g, b, r, g, b, r, g, b, r, g, b,
+  };
+
   auto pixels = display.pixels();
-  for (int i = 0; i < (wi + 1) * (hi + 1); i++)
+  for (int i = 0; i < (wi + 1) * (hi + 1); i += 8)
   {
-    pixels.write(r, g, b);
+    pixels.write(buf, sizeof(buf));
   }
 }
 
@@ -61,15 +66,21 @@ int main()
   absolute_time_t previous_time = get_absolute_time();
   float time_since_last_display = 0;
 
-  constexpr float SPEED = 100;
+  constexpr float SPEED = 75;
   float paddle_x = 120;
   constexpr float paddle_y = 280;
 
+  constexpr float BALL_SPEED = 125;
+  float ball_x = 120;
+  float ball_y = 160;
+
+  float INITIAL_BALL_ANGLE = -3.1415926f / 4.0f;
+  float ball_dx = cosf(INITIAL_BALL_ANGLE);
+  float ball_dy = sinf(INITIAL_BALL_ANGLE);
+
   uint8_t left_history = 0;
   uint8_t right_history = 0;
 
-  bool moved = true;
-
   while (true)
   {
     tud_task();
@@ -77,6 +88,34 @@ int main()
     float dt = absolute_time_diff_us(previous_time, current) / 1000000.0f;
     previous_time = current;
 
+    float old_ball_pos_x = ball_x;
+    float old_ball_pos_y = ball_y;
+
+    ball_x += ball_dx * BALL_SPEED * dt;
+    ball_y += ball_dy * BALL_SPEED * dt;
+
+    if (ball_x - 2 <= 0 || ball_x + 2 >= 240)
+    {
+      ball_dx = -ball_dx;
+      ball_x += ball_dx * 2;
+    }
+    if (ball_y - 2 <= 0 || ball_y + 2 >= 320)
+    {
+      ball_dy = -ball_dy;
+      ball_y += ball_dy * 2;
+    }
+
+    if (ball_x + 2 >= paddle_x - 20 && ball_x - 2 <= paddle_x + 20
+        && ball_y + 3 >= paddle_y - 2 && ball_y - 3 <= paddle_y - 2)
+    {
+      float ball_angle = atan2f(ball_dy, ball_dx);
+      float diff = paddle_x - ball_x;
+      ball_angle += diff / 50.0f;
+      ball_dx = cosf(ball_angle);
+      ball_dy = -sinf(ball_angle);
+      ball_y = paddle_y - 6;
+    }
+
     float old_pos = paddle_x;
 
     left_history = (left_history << 1) | !gpio_get(BUTTON_LEFT);
@@ -85,21 +124,24 @@ int main()
     if (left_history == 0xFF)
     {
       paddle_x -= SPEED * dt;
-      moved = true;
     }
 
     if (right_history == 0xFF)
     {
       paddle_x += SPEED * dt;
-      moved = true;
     }
 
     time_since_last_display += dt;
 
-    if (moved && time_since_last_display > 0.016f)
+    if (time_since_last_display > 0.02f)
     {
-      moved = false;
-      draw_rectangle(old_pos, paddle_y, 50, 7, 0, 0, 0);
+      // ball
+      draw_rectangle(old_ball_pos_x, old_ball_pos_y, 12, 12, 0, 0, 0);
+      draw_rectangle(ball_x, ball_y, 4, 4, 0xFF, 0xFF, 0xFF);
+
+      // player paddle
+      draw_rectangle(old_pos - 20, paddle_y, 6, 7, 0, 0, 0);
+      draw_rectangle(old_pos + 20, paddle_y, 6, 7, 0, 0, 0);
       draw_rectangle(paddle_x, paddle_y, 40, 5, 0xFF, 0xFF, 0xFF);
       time_since_last_display = 0;
     }

src/usb_descriptors.c

@@ -46,7 +46,10 @@ enum
 };
 
 const char* string_desc_arr[]
-  = { (const char[]){ 0x09, 0x04 }, "shylie.info", "MtG Token", NULL };
+  = { [STRID_LANGID] = (const char[]){ 0x09, 0x04 },
+      [STRID_MANUFACTURER] = "shylie.info",
+      [STRID_PRODUCT] = "card device",
+      [STRID_SERIAL] = NULL };
 
 const uint16_t* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
 {