Generate labels with pangocairo (#8)

Goal of this PR is to have some basic labels generated with pangocairo
- size of the canvas should be matching the input text and grow/shrink accordingly
- basic formatting options like fontsize and align should be working

Reviewed-on: moritz/ptouch-prnt#8

src/graphics/Bitmap.cpp

@@ -1,6 +1,6 @@
 /* 
     ptrnt - print labels on linux
-    Copyright (C) 2023  Moritz Martinius
+    Copyright (C) 2023-2025  Moritz Martinius
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -19,32 +19,30 @@
 
 #include "Bitmap.hpp"
 
-#include <algorithm>
 #include <spdlog/spdlog.h>
 
-#include <iterator>
-#include <optional>
+#include <ranges>
+#include <stdexcept>
 #include <vector>
 
 namespace ptprnt::graphics {
 template <class T>
-Bitmap<T>::Bitmap(uint16_t width, uint16_t height)
-    : mWidth{width}, mHeight{height}, mPixels(width * height) {}
+Bitmap<T>::Bitmap(uint16_t width, uint16_t height) : mWidth{width}, mHeight{height}, mPixels(width * height) {}
 
 template <class T>
-uint16_t Bitmap<T>::getWidth() {
+[[nodiscard]] uint16_t Bitmap<T>::getWidth() const {
     return mWidth;
 }
 
 template <class T>
-uint16_t Bitmap<T>::getHeight() {
+[[nodiscard]] uint16_t Bitmap<T>::getHeight() const {
     return mHeight;
 }
 
 template <class T>
 bool Bitmap<T>::setPixels(const std::vector<T>& pixels) {
     if (pixels.size() != mPixels.size()) {
-        spdlog::error("Invalid pixel buffer size.");
+        spdlog::error("Invalid pixel buffer size (got {} vs. {} bitmap size).", pixels.size(), mPixels.size());
         return false;
     }
 
@@ -53,39 +51,34 @@ bool Bitmap<T>::setPixels(const std::vector<T>& pixels) {
 }
 
 template <class T>
-std::vector<T> Bitmap<T>::getPixelsCpy() {
+[[nodiscard]] std::vector<T> Bitmap<T>::getPixelsCpy() const {
     return mPixels;
 }
 
 template <class T>
-std::optional<std::vector<T>> Bitmap<T>::getLine(uint16_t line) {
-    if (line >= mHeight) {
-        // out of bound
-        return std::nullopt;
+[[nodiscard]] std::vector<T> Bitmap<T>::getLine(const uint16_t lineNo) const {
+    if (lineNo >= mHeight) {
+        throw(std::out_of_range("Line is out of range!"));
     }
-
-    auto lineStart = mPixels.begin() + (line * mWidth);
-    auto lineEnd   = mPixels.begin() + ((line + 1) * mWidth);
+    auto lineStart = mPixels.begin() + (lineNo * mWidth);
+    auto lineEnd   = mPixels.begin() + ((lineNo + 1) * mWidth);
     return std::vector<T>(lineStart, lineEnd);
 }
 
+// TODO: I guess this is borked
 template <class T>
-std::optional<std::vector<T>> Bitmap<T>::getCol(uint16_t col) {
-    if (col >= mWidth) {
-        // out of bound
-        return std::nullopt;
+[[nodiscard]] std::vector<T> Bitmap<T>::getCol(const uint16_t colNo) const {
+    if (colNo >= mWidth) {
+        throw(std::out_of_range("Col is out of range!"));
     }
 
-    // first pixel is always beginning of the col
-    std::vector<T> colPixels(mHeight);
-    auto it = std::next(mPixels.begin(), col);
-
-    for (auto& colElement : colPixels) {
-        colElement = *it;
-        std::advance(it, mWidth);
+    std::vector<T> col{};
+    col.reserve(mHeight);
+    for (size_t i{0}; i <= mPixels.size(); i++) {
+        if (i % mWidth == colNo) {
+            col.push_back(mPixels[i]);
+        }
     }
-
-    return colPixels;
+    return col;
 }
-
 }  // namespace ptprnt::graphics