feat: added text rendering class

Thesis/Thesis.tex

@@ -1791,13 +1791,13 @@ void TextRenderer::Load(const std::string &font, unsigned int fontSize)
 \label{fig:loadingFont}
 \end{figure}
 
-\paragraph{Loading characters}
+\subsubsection{Loading characters}
 In order to preload ASCII characters we use a method loadCharacter from TextRenderer, it uses FreeType library to load character, then generates textures for a character (it needs to allign a texture to character), sets options for texture and adds the character object to characters array
 
 \begin{figure}[htp]
 \centering
 \begin{tikzpicture}[node distance=1.5cm]
-\useasboundingbox (-5,0) rectangle (5, -13cm);  % Set a custom bounding box
+\useasboundingbox (-5,0) rectangle (5, -10cm);  % Set a custom bounding box
 \node (start) [startstop] {Load character};
 \node (pro1) [process, below of=start] {Load character using FreeType};
 \draw [arrow] (start) -- (pro1);
@@ -1822,6 +1822,49 @@ In order to preload ASCII characters we use a method loadCharacter from TextRend
 \label{fig:loadingCharacter}
 \end{figure}
 
+\newpage
+\paragraph{Texture options}
+
+\begin{itemize}
+    \item The first two lines set the wrapping mode of the texture in the S and T directions (usually the x and y axes) to \texttt{GL\_CLAMP\_TO\_EDGE}. This means if the texture coordinates go beyond [0,1], the texture will not repeat but instead clamp to the edge values.
+    \item The next two lines set the minification and magnification filter to \texttt{GL\_LINEAR}. This means when the texture is scaled down or up, it will use linear interpolation between the texture coordinates, resulting in a smoother texture appearance.
+\end{itemize}
+
+\begin{lstlisting}[style=C++Style]
+void TextRenderer::setTextureOptions() const {
+    // set texture options
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+}
+\end{lstlisting}
+
+\newpage
+\subsubsection{Rendering text}
+We are given text as a C++ string and a position, method is supposed to automatically render text so that it fits in a position that was provided \\
+We achieve that by iterating through each character of a string and putting it next to each other at a gap equal to a previous character width and height
+
+\begin{figure}[htp]
+\centering
+\includegraphics[scale=1.00]{images/glyph_offset.png}
+\caption{Glyph metrics from learnopengl}
+\label{}
+\end{figure}
+
+Calculating x and y positions of each character \\
+$x_{pos}$ and $y_{pos}$ is the final x/y position of character \\
+$x_{start}$ and $y_{start}$ is the position inputed to the method render text \\
+$x_{bearing}$ and $y_{bearing}$ is a parameter shown in image above \\
+$s$ is scale \\
+We calculate final bearing of $y_{pos}$ by subtracting bearing of "H" character from the bearing of actual character, we do it this way because "y" bearing of "H" character is highest \\
+\[
+x_{pos} = x_{start} + x_{bearing} * s
+\]
+\[
+y_{pos} = y_{start} + (H_{bearing} - y_{bearing}) * s
+\]
+
 \subsection{Dependency Management}
 There are several libraries: OpenGL, GLFW, stb\_image and freetype being integrated into engine, they are simply included at the top of any files that need them.