RGB565: unit tests and default constructor zeroes memory

Author: danngreen

tests/rgb565_tests.cc

@@ -0,0 +1,25 @@
+#include "doctest.h"
+#include "util/colors_rgb565.hh"
+
+TEST_CASE("Basic usage") {
+
+	RGB565 c1;
+	RGB565 c2{};
+	RGB565 c3{(uint8_t)0x80, 0x40, 0x20};
+	RGB565 c4{0.5f, 0.25f, 0.125f};
+	RGB565 c5{0x804020};
+
+	CHECK(c1.raw() == 0);
+	CHECK(c2.raw() == 0);
+	CHECK(c3.raw() == 0x8204);
+	CHECK(c4.raw() == 0x8204);
+	CHECK(c5.raw() == 0x8204);
+
+	CHECK(c5.red() == 0x80);
+	CHECK(c5.green() == 0x40);
+	CHECK(c5.blue() == 0x20);
+
+	c1 = 0x2334;
+	CHECK(c1.raw() == 0x2334);
+	CHECK((uint16_t)c1 == 0x2334);
+}

util/colors_rgb565.hh

@@ -5,11 +5,14 @@
 
 struct RGB565 {
 	// msb> rrrrr gggggg bbbbb <lsb
-	uint16_t b : 5;
-	uint16_t g : 6;
-	uint16_t r : 5;
+	uint16_t b : 5 {};
+	uint16_t g : 6 {};
+	uint16_t r : 5 {};
 
-	constexpr RGB565() {
+	constexpr RGB565()
+		: b{0}
+		, g{0}
+		, r{0} {
 	}
 
 	constexpr RGB565(uint8_t red, uint8_t green, uint8_t blue)