Add triangle example

gfx2d/CMakeLists.txt

@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.13)
+
+add_executable(gfx2d
+  src/main.cpp
+)
+
+target_link_libraries(gfx2d common picoled hardware_pwm)
+
+pico_enable_stdio_uart(gfx2d 0)
+pico_enable_stdio_usb(gfx2d 1)
+
+pico_add_extra_outputs(gfx2d)

gfx2d/src/main.cpp

@@ -0,0 +1,100 @@
+#include <cmath>
+#include <cstdlib>
+
+#include <hardware/structs/io_bank0.h>
+#include <pico/stdio_usb.h>
+#include <pico/time.h>
+#include <picoled/SSD1306.h>
+#include <picoled/gfx/2D.h>
+
+#include <pico/stdlib.h>
+#include <hardware/pwm.h>
+
+using namespace picoled;
+
+namespace
+{
+
+float get_random()
+{
+  return rand() / static_cast<float>(RAND_MAX);
+}
+
+int32_t get_encoder_delta(i2c_inst* i2c, uint8_t address)
+{
+  // SEESAW_ENCODER_BASE and SEESAW_ENCODER_DELTA values
+  // https://github.com/adafruit/Adafruit_Seesaw/blob/master/Adafruit_seesaw.h
+  uint8_t buf[4] = { 0x11, 0x40, 0x00, 0x00 };
+  i2c_write_blocking(i2c, address, buf, 2, false);
+  sleep_us(250);
+  i2c_read_blocking(i2c, address, buf, 4, false);
+  return
+    (static_cast<int32_t>(buf[0]) << 24) |
+    (static_cast<int32_t>(buf[1]) << 16) |
+    (static_cast<int32_t>(buf[2]) << 8 ) |
+    (static_cast<int32_t>(buf[3]) << 0 );
+}
+
+constexpr uint8_t LEFT_ENCODER_ADDRESS = 0x36;
+constexpr uint8_t RIGHT_ENCODER_ADDRESS = 0x37;
+constexpr uint8_t OLED_ADDRESS = 0x3C;
+
+}
+
+int main()
+{
+  stdio_usb_init();
+  srand(time_us_64());
+
+  i2c_init(i2c0, 1000 * 1000);
+  gpio_set_function(0, GPIO_FUNC_I2C);
+  gpio_set_function(1, GPIO_FUNC_I2C);
+  gpio_pull_up(0);
+  gpio_pull_up(1);
+
+  ssd1306 oled(i2c0, OLED_ADDRESS);
+  gfx::gfx2d gfx(oled);
+
+  float angle;
+  int64_t time = time_us_32();
+
+  buffer<pixel> tex(16, 16);
+  for (int x = 0; x < 16; x++)
+  {
+    for (int y = 0; y < 16; y++)
+    {
+      tex.write(x, y, x * y);
+    }
+  }
+
+  while (true)
+  {
+    oled.clear();
+
+    int64_t current = time_us_32();
+    const float dt = std::abs(current - time) / 1000000.0f;
+    time = current;
+
+    angle -= get_encoder_delta(i2c0, RIGHT_ENCODER_ADDRESS) / 12.0f * 3.1415926f;
+
+    const float angle2 = angle + (2 * 3.1415926f) / 3;
+    const float angle3 = angle + 2 * (2 * 3.1415926f) / 3;
+
+    const gfx::vec2 ap = { 30.0f + 20 * cosf(angle), 30.0f + 20 * sinf(angle) };
+    const gfx::vec2 bp = { 30.0f + 20 * cosf(angle2), 30.0f + 20 * sinf(angle2) };
+    const gfx::vec2 cp = { 30.0f + 20 * cosf(angle3), 30.0f + 20 * sinf(angle3) };
+
+    const gfx::vec2 at = { 0.0f, 0.0f };
+    const gfx::vec2 bt = { 0.0f, 0.0f };
+    const gfx::vec2 ct = { 1.0f, 1.0f };
+
+    gfx.draw_triangle({
+      { ap, at },
+      { bp, bt },
+      { cp, ct }
+    }, tex);
+
+    oled.swap_buffers();
+    oled.update();
+  }
+}

picoled

@@ -1 +1 @@
-Subproject commit 10e9176d13b249e2705745a441aa333d8a2c1823
+Subproject commit dfeccd50b9d2e3583675b80cd4225cb98215356c

pong/src/main.cpp

@@ -231,7 +231,7 @@ int main()
     ai.draw(oled);
     ball.draw(oled);
 
-    oled.update();
     oled.swap_buffers();
+    oled.update();
   }
 }