Moved graphics classes into own namespace, added unit testing with gtest

tests/bitmap_test/bitmap_test.cpp

@@ -0,0 +1,47 @@
+#include "graphics/Bitmap.hpp"
+
+#include <gtest/gtest.h>
+
+#include <optional>
+
+TEST(basic_test, Bitmap_createBitmapWithCertainSize_yieldsSpecifiedSize) {
+    auto bm     = ptprnt::graphics::Bitmap<ptprnt::graphics::ALPHA8>(16, 8);
+    auto width  = bm.getWidth();
+    auto height = bm.getHeight();
+    ASSERT_EQ(width, 16);
+    ASSERT_EQ(height, 8);
+}
+
+TEST(basic_test, Bitmap_getBitmapLineOutsideOfImage_yieldsNullopt) {
+    auto bm = ptprnt::graphics::Bitmap<ptprnt::graphics::ALPHA8>(16, 8);
+    // line 8 is out of bounds, count begins with 0
+    auto outOfBoundsLine = bm.getLine(8);
+    ASSERT_EQ(std::nullopt, outOfBoundsLine);
+}
+
+TEST(basic_test, Bitmap_getBitmapLineInsideOfImage_yieldsValidLineSize) {
+    auto bm   = ptprnt::graphics::Bitmap<ptprnt::graphics::ALPHA8>(16, 8);
+    auto line = bm.getLine(7);
+    if (!line) {
+        FAIL() << "Returned line is invalid";
+    }
+    auto lineSize = line->size();
+    ASSERT_EQ(16, lineSize);
+}
+
+TEST(basic_test, Bitmap_getBitmapRowOutsideOfImage_yieldsNullopt) {
+    auto bm = ptprnt::graphics::Bitmap<ptprnt::graphics::ALPHA8>(16, 8);
+    // row 16 is out of bounds, count begins with 0
+    auto outOfBoundsRow = bm.getRow(16);
+    ASSERT_EQ(std::nullopt, outOfBoundsRow);
+}
+
+TEST(basic_test, Bitmap_getBitmapRowInsideOfImage_yieldsValidRowSize) {
+    auto bm  = ptprnt::graphics::Bitmap<ptprnt::graphics::ALPHA8>(16, 8);
+    auto row = bm.getRow(15);
+    if (!row) {
+        FAIL() << "Returned Row is invalid";
+    }
+    auto rowSize = row->size();
+    ASSERT_EQ(8, rowSize);
+}