[Add] Implement initial interactive terminal.

client/src/main.cpp

@@ -1,7 +1,9 @@
 #include <cstdio>
-#include "gfx/txt_renderer.h"
 #include <GL/glew.h>
 #include <SDL3/SDL.h>
+#include <SDL3/SDL_keyboard.h>
+
+#include "terminal.h"
 
 const int SCREEN_WIDTH  = 1280;
 const int SCREEN_HEIGHT = 720;
@@ -49,18 +51,24 @@ int main(int argc, char** argv) {
   glEnable(GL_BLEND);
   glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
+  /* Listen for text input. */
+  SDL_StartTextInput(window);
+
   /* Init text renderer. */
   TextRenderer* txt_render_instance = new TextRenderer(SCREEN_WIDTH, SCREEN_HEIGHT);
-  txt_render_instance->load_font("assets/fonts/hack/Hack-Regular.ttf", 24);
+  txt_render_instance->load_font("assets/fonts/hack/Hack-Regular.ttf", 14);
+
+  /* Create terminal. */
+  Terminal* term = new Terminal();
 
   bool running = true;
   while(running) {
     /* Event handling. */
     SDL_Event event;
     while(SDL_PollEvent(&event)) {
-      if(event.type == SDL_EVENT_QUIT) {
-        running = false;
-      }
+      if(event.type == SDL_EVENT_QUIT) { running = false; }
+      /* Pass input to terminal. */
+      term->handle_input(&event);
     }
 
     /* Clear screen. */
@@ -69,14 +77,14 @@ int main(int argc, char** argv) {
 
     /* Render text. */
     float white[] = { 1.0f, 1.0f, 1.0f };
-    txt_render_instance->render_text("Hello World", 25.0f, SCREEN_HEIGHT - 50.0f, 
-                                     1.0f, white);
+    term->render(txt_render_instance);
 
     /* It's really odd to call it SwapWindow now, rather than SwapBuffer. */
     SDL_GL_SwapWindow(window);
   }
 
   /* Cleanup. */
+  delete term;
   delete txt_render_instance;
   SDL_GL_DestroyContext(context);
   SDL_DestroyWindow(window);

client/src/terminal.cpp

@@ -0,0 +1,57 @@
+#include <cstdio>
+#include "gfx/txt_renderer.h"
+#include "terminal.h"
+#include <SDL3/SDL_events.h>
+#include <SDL3/SDL_keycode.h>
+
+Terminal::Terminal(void) {
+  /* Placeholder welcome message to history. */
+  _history.push_back("Welcome to Bettola");
+}
+
+void Terminal::_on_ret_press(void) {
+  /* Add the command to history. */
+  _history.push_back("> " + _input_buffer);
+
+  /* For now, print the commmand clear buffer.
+   * TODO: Parse and execute commands.
+   */
+  printf("Command entered: %s\n", _input_buffer.c_str());
+
+  if(_input_buffer == "clear") {
+    _history.clear();
+  } else if(_input_buffer == "help") {
+    _history.push_back("Commands: help, clear");
+  }
+
+  _input_buffer.clear();
+}
+
+void Terminal::handle_input(SDL_Event* event) {
+  if(event->type == SDL_EVENT_TEXT_INPUT) {
+    /* Append chars to the input buffer. */
+    _input_buffer += event->text.text;
+  } else if(event->type == SDL_EVENT_KEY_DOWN) {
+    /* Handle special keys. */
+    if(event->key.key == SDLK_BACKSPACE && _input_buffer.length() > 0) {
+      _input_buffer.pop_back();
+    } else if(event->key.key == SDLK_RETURN) {
+      _on_ret_press();
+    }
+  }
+}
+
+void Terminal::render(TextRenderer* renderer) {
+  float white[]     = { 1.0f, 1.0f, 1.0f };
+  float green[]     = { 0.2f, 1.0f, 0.2f };
+  float line_height = 28.0f;
+
+  /* Draw history. */
+  for(size_t i = 0; i < _history.size(); ++i) {
+    renderer->render_text(_history[i].c_str(), 25.0f, 720.0f-50.0f-(i*line_height), 1.0f, white);
+  }
+
+  /* Draw current input line. */
+  std::string prompt = "> " + _input_buffer;
+  renderer->render_text(prompt.c_str(), 25.0f, 720.0f-50.0f-(_history.size()*line_height), 1.0f, green);
+}

client/src/terminal.h

@@ -0,0 +1,20 @@
+#pragma once
+#include <string>
+#include <vector>
+#include <SDL3/SDL.h>
+
+#include "gfx/txt_renderer.h"
+
+class Terminal {
+public:
+  Terminal(void);
+
+  void handle_input(SDL_Event* event);
+  void render(TextRenderer* renderer);
+
+private:
+  void _on_ret_press(void);
+
+  std::string _input_buffer;
+  std::vector<std::string> _history;
+};