From 01147c0d35994d77d2922cb0e302857b49a49d43 Mon Sep 17 00:00:00 2001
From: Aaron Mueller <mail@aaron-mueller.de>
Date: Wed, 16 Dec 2009 15:37:24 +0100
Subject: [PATCH] Adding game states and menu

 * Implement a simple state machine to simulate different game stats
 * Create a generic menu to display different menus
 * Update the Makefile for TTF support
 * Draw a simple diagram to show the stats
---
 Makefile                 |  2 +-
 snippets/state_graph.dot | 21 ++++++++++++
 src/config.c             |  4 +++
 src/config.h             | 29 ++++++++++++----
 src/display.c            | 44 ++++++++++++++++++++++++
 src/draw.c               | 16 ---------
 src/draw.h               |  9 ++---
 src/events.c             | 42 +++++++++++++++++++++++
 src/main.c               | 40 +++++++++++-----------
 src/menu.c               | 72 ++++++++++++++++++++++++++++++++++++++++
 src/menu.h               | 23 +++++++++++++
 src/states.c             | 17 ++++++++++
 src/states.h             | 34 +++++++++++++++++++
 13 files changed, 302 insertions(+), 51 deletions(-)
 create mode 100644 snippets/state_graph.dot
 create mode 100644 src/display.c
 create mode 100644 src/events.c
 create mode 100644 src/menu.c
 create mode 100644 src/menu.h
 create mode 100644 src/states.c
 create mode 100644 src/states.h

diff --git a/Makefile b/Makefile
index dc00a6c..55a5f38 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ CC=       gcc
 # Compiler flags
 CFLAGS=   -Wall -std=c99 -ggdb
 # Libraries
-CLIBS=    `sdl-config --cflags` -lSDL -lGL
+CLIBS=    `sdl-config --cflags` -lSDL -lSDL_ttf -lGL
 ####### Commands
 RM=       rm -r
 MKDIR=    mkdir -p
diff --git a/snippets/state_graph.dot b/snippets/state_graph.dot
new file mode 100644
index 0000000..b62a316
--- /dev/null
+++ b/snippets/state_graph.dot
@@ -0,0 +1,21 @@
+
+// dot -Tpng -Gcharset=latin1 state_graph.dot -o states.png
+
+digraph StateMachine {
+  node [style=rounded, shape=box, fontname="Helvetica"];
+  edge [fontsize=9, fontname="Helvetica"];
+
+  Start [shape=plaintext];
+  Ende [shape=plaintext];
+ 
+  Start -> "Hauptmenü";
+  "Hauptmenü" -> Ende [label="Spiel beenden"];
+  "Hauptmenü" -> Spielerwahl [label="Neues Spiel",labelfontsize=4.0];
+  "Hauptmenü" -> Credits [label="Credits"];
+  Credits -> "Hauptmenü" [label="Zurück"];
+  Spielerwahl -> "Hauptmenü" [label="Zurück"];
+  Spielerwahl -> "Spiel läuft" [label="1/2/3 Spieler"];
+  "Spiel läuft" -> "Spiel wirklich beenden?" [label="ESC, F10"];
+  "Spiel wirklich beenden?" -> "Hauptmenü" [label="Ja"];
+  "Spiel wirklich beenden?" -> "Spiel läuft" [label="Nein"];
+}
diff --git a/src/config.c b/src/config.c
index f49bae8..e50a810 100644
--- a/src/config.c
+++ b/src/config.c
@@ -6,6 +6,10 @@
 // Initialization for the global variables
 SDL_Surface *screen = NULL;
 SDL_Event event;
+TTF_Font *menuFont;
 bool gameRunning = true;
 int *terrain = NULL;
 
+enum states currentState;
+int currentMenuActionState = 0;
+
diff --git a/src/config.h b/src/config.h
index 9cb6ffc..e650fff 100644
--- a/src/config.h
+++ b/src/config.h
@@ -1,19 +1,36 @@
 
 #include <stdbool.h>
 #include "SDL.h"
+#include "SDL_ttf.h"
 
 // In this file we define all global variables for the whole project. All
 // variables definied here can be accessed from all other source files.
 
-// Global variables and definitions
-extern SDL_Surface *screen; // Screen to paint on
-extern SDL_Event event; // Event storage
-extern bool gameRunning; // Set this variable to false to shutdown the game
-extern int *terrain; // Game terrain
-
 // Constants
+#ifndef CONFIG_H
+#define CONFIG_H
+enum states {
+  STATE_MAINMENU,
+  STATE_NUMPLAYERS,
+  STATE_CREDITS,
+  STATE_RUNNINGGAME,
+  STATE_RLYQUIT,
+  STATE_EXIT,
+  MAX_STATES
+};
 
 // Screen size
 static const int SCREEN_WIDTH = 800;
 static const int SCREEN_HEIGHT = 600;
 
+#endif
+
+
+// Global variables and definitions
+extern SDL_Surface *screen; // Screen to paint on
+extern SDL_Event event; // Event storage
+extern TTF_Font *menuFont; // The font for the menu
+extern int *terrain; // Game terrain
+extern enum states currentState; // The current game state
+extern int currentMenuActionState; // The current selected action state in a menu
+
diff --git a/src/display.c b/src/display.c
new file mode 100644
index 0000000..f673f67
--- /dev/null
+++ b/src/display.c
@@ -0,0 +1,44 @@
+
+#include <stdlib.h>
+#include <stdio.h>
+#include "SDL.h"
+#include "SDL_ttf.h"
+#include "config.h"
+#include "states.h"
+#include "draw.h"
+#include "menu.h"
+
+void displayMainmenu() {
+  drawMenu(mainMenu, 3);
+}
+
+void displayNumplayers() {
+  drawMenu(numplayersMenu, 4);
+}
+
+void displayCredits() {
+  drawMenu(creditsMenu, 1);
+}
+
+void displayRunninggame() {
+  if (terrain == NULL) terrain = generateTerrain(150.0, 180.0);
+
+  Uint32 sky = SDL_MapRGB(screen->format, 186, 215, 217);
+  Uint32 green = SDL_MapRGB(screen->format, 101, 200, 21);
+  Uint32 darkGreen = SDL_MapRGB(screen->format, 52, 99, 14);
+  Uint32 ground = SDL_MapRGB(screen->format, 124, 88, 10);
+
+  for (int x=0; x<SCREEN_WIDTH; x++) {
+    int y = terrain[x];
+
+    drawLine(x, 0, x, y, sky);
+    if (y <= SCREEN_HEIGHT-15) drawLine(x, y, x, y+15, green);
+    if (y <= SCREEN_HEIGHT-20) drawLine(x, y+15, x, y+20, darkGreen);
+    if (y <= SCREEN_HEIGHT-21) drawLine(x, y+20, x, SCREEN_HEIGHT, ground);
+  }
+}
+
+void displayRlyquit() {
+  drawMenu(rlyquitMenu, 2);
+}
+
diff --git a/src/draw.c b/src/draw.c
index 29e585d..411e92d 100644
--- a/src/draw.c
+++ b/src/draw.c
@@ -97,19 +97,3 @@ int* generateTerrain(float peakheight, float flatness) {
   return &(yvals[0]);
 }
 
-void drawScreen() {
-  Uint32 sky = SDL_MapRGB(screen->format, 186, 215, 217);
-  Uint32 green = SDL_MapRGB(screen->format, 101, 200, 21);
-  Uint32 darkGreen = SDL_MapRGB(screen->format, 52, 99, 14);
-  Uint32 ground = SDL_MapRGB(screen->format, 124, 88, 10);
-
-  for (int x=0; x<SCREEN_WIDTH; x++) {
-    int y = terrain[x];
-
-    drawLine(x, 0, x, y, sky);
-    if (y <= SCREEN_HEIGHT-15) drawLine(x, y, x, y+15, green);
-    if (y <= SCREEN_HEIGHT-20) drawLine(x, y+15, x, y+20, darkGreen);
-    if (y <= SCREEN_HEIGHT-21) drawLine(x, y+20, x, SCREEN_HEIGHT, ground);
-  }
-}
-
diff --git a/src/draw.h b/src/draw.h
index 1f2ce60..ec8b828 100644
--- a/src/draw.h
+++ b/src/draw.h
@@ -14,14 +14,9 @@ void drawLine(int x1, int y1, int x2, int y2, int color);
 void drawRect(int x1, int y1, int x2, int y2, int color, bool filled);
 void drawCircle(int x, int y, int radius, int color, bool filled);
 
-
+/* Terrain generator
+ */
 int* generateTerrain(float peakheight, float flatness);
  
-/*
- * This function will be called for every frame. Here you can actual draw things
- * on the screen.
- */
-void drawScreen();
-
 #endif
 
diff --git a/src/events.c b/src/events.c
new file mode 100644
index 0000000..d29daf8
--- /dev/null
+++ b/src/events.c
@@ -0,0 +1,42 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "config.h"
+#include "states.h"
+#include "menu.h"
+#include "draw.h"
+
+void eventsMainmenu() {
+  handleMenuEvent(mainMenu, 3, STATE_EXIT);
+}
+
+void eventsNumplayers() {
+  handleMenuEvent(numplayersMenu, 4, STATE_MAINMENU);
+}
+
+void eventsCredits() {
+  handleMenuEvent(creditsMenu, 1, STATE_MAINMENU);
+}
+
+void eventsRunninggame() {
+  if (event.type == SDL_KEYDOWN) {
+    switch (event.key.keysym.sym) {
+      case SDLK_RETURN:
+        free(terrain);
+        terrain = generateTerrain(150.0, 180.0);
+        printf("New terrain generated.\n");
+        break;
+      case SDLK_ESCAPE:
+      case SDLK_F10:
+        currentState = STATE_RLYQUIT;
+        break;
+      default:
+        break;
+    }
+  }
+}
+
+void eventsRlyquit() {
+  handleMenuEvent(rlyquitMenu, 2, STATE_RUNNINGGAME);
+}
+
diff --git a/src/main.c b/src/main.c
index ee29ffe..4fc146b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,47 +2,45 @@
 #include <stdio.h>
 #include <stdbool.h>
 #include <stdlib.h>
+#include <time.h>
 #include "SDL.h"
+#include "SDL_ttf.h"
 #include "config.h"
 #include "draw.h"
+#include "states.h"
+#include "menu.h"
+
 
 int main(int argc, char **argv) {
   // Initialize SDL and open up a screen
   SDL_Init(SDL_INIT_VIDEO);
+  TTF_Init();
   screen = SDL_SetVideoMode(SCREEN_WIDTH, SCREEN_HEIGHT, 32, SDL_HWSURFACE | SDL_DOUBLEBUF);
+  menuFont = TTF_OpenFont("/usr/share/fonts/corefonts/verdana.ttf", 50);
+
+  currentState = STATE_MAINMENU;
 
   // Initialize internal game state
   srand(time(NULL));
   terrain = generateTerrain(150.0, 180.0);
-  
+
+
+  // Choose right state
+  stateTable[currentState].drawFun();
+  stateTable[currentState].handleEventsFun();
+
   // the main game loop
-  while (gameRunning == true) {
+  while (currentState != STATE_EXIT) {
     // Check for events
     if (SDL_PollEvent(&event)) {
       // Make it possible to close the game window
-      if (event.type == SDL_QUIT) gameRunning = false;
-
-      // Keyboard interaction
-      if (event.type == SDL_KEYDOWN) {
-        switch (event.key.keysym.sym) {
-          case SDLK_RETURN:
-            free(terrain);
-            terrain = generateTerrain(150.0, 180.0);
-            printf("New terrain generated.\n");
-            break;
-          case SDLK_ESCAPE:
-          case SDLK_F10:
-            gameRunning = false;
-            break;
-          default:
-            break;
-        }
-      }
+      if (event.type == SDL_QUIT) currentState = STATE_EXIT;
+      stateTable[currentState].handleEventsFun();
     }
 
     // Draw the stuff on the screen and "flip" th the next frame
     SDL_FillRect(screen, NULL, 0x000000);
-    drawScreen();
+    stateTable[currentState].drawFun();
     SDL_Flip(screen);
   }
 
diff --git a/src/menu.c b/src/menu.c
new file mode 100644
index 0000000..5094666
--- /dev/null
+++ b/src/menu.c
@@ -0,0 +1,72 @@
+
+#include "SDL.h"
+#include "states.h"
+#include "menu.h"
+
+
+struct menuItem mainMenu[] = {
+  {"Neues Spiel", STATE_NUMPLAYERS},
+  {"Credits", STATE_CREDITS},
+  {"Spiel beenden", STATE_EXIT}
+};
+struct menuItem numplayersMenu[] = {
+  {"Einspieler", STATE_RUNNINGGAME},
+  {"Zweispieler", STATE_RUNNINGGAME},
+  {"Dreispieller", STATE_RUNNINGGAME},
+  {"Zurueck", STATE_MAINMENU}
+};
+struct menuItem creditsMenu[] = {
+  {"Zurueck", STATE_MAINMENU}
+};
+struct menuItem rlyquitMenu[] = {
+  {"Beenden", STATE_MAINMENU},
+  {"Weiterspielen", STATE_RUNNINGGAME}
+};
+
+void handleMenuEvent(struct menuItem items[], int numItems, enum states prevState) {
+  if (event.type == SDL_KEYDOWN) {
+    switch (event.key.keysym.sym) {
+      case SDLK_DOWN:
+      case SDLK_j:
+        currentMenuActionState++;
+        if (currentMenuActionState > numItems-1) currentMenuActionState = 0;
+        break;
+      case SDLK_UP:
+      case SDLK_k:
+        currentMenuActionState--;
+        if (currentMenuActionState < 0) currentMenuActionState = numItems-1;
+        break;
+      case SDLK_RETURN:
+      case SDLK_SPACE:
+        currentState = items[currentMenuActionState].targetState;
+        currentMenuActionState = 0;
+        break;
+      case SDLK_ESCAPE:
+      case SDLK_BACKSPACE:
+        currentMenuActionState = 0;
+        currentState = prevState;
+        break;
+      default:
+        break;
+    }
+  }
+}
+
+void drawMenu(struct menuItem items[], int numItems) {
+  SDL_Surface *text;
+  SDL_Rect targetPos;
+
+  SDL_Color colorSelected = {0, 255, 66};
+  SDL_Color colorNormal = {59, 71, 62};
+  
+  for (int i=0; i<numItems; i++) {
+    targetPos.x = 200;
+    targetPos.y = i*60+200;
+    targetPos.w = SCREEN_WIDTH-200;
+    targetPos.h = 50;
+    text = TTF_RenderText_Solid(menuFont, items[i].buttonDescription,
+        currentMenuActionState == i ? colorSelected : colorNormal);
+    SDL_BlitSurface(text, NULL, screen, &targetPos);
+  }
+}
+
diff --git a/src/menu.h b/src/menu.h
new file mode 100644
index 0000000..5690f6a
--- /dev/null
+++ b/src/menu.h
@@ -0,0 +1,23 @@
+
+#ifndef MENU_H
+#define MENU_H
+
+#include "states.h"
+#include "config.h"
+
+struct menuItem {
+  char buttonDescription[30];
+  enum states targetState;
+};
+
+struct menuItem mainMenu[3];
+struct menuItem numplayersMenu[4];
+struct menuItem creditsMenu[1];
+struct menuItem rlyquitMenu[2];
+
+
+void handleMenuEvent(struct menuItem items[], int numItems, enum states prevState);
+void drawMenu(struct menuItem items[], int numItems);
+
+#endif
+
diff --git a/src/states.c b/src/states.c
new file mode 100644
index 0000000..7f73ec6
--- /dev/null
+++ b/src/states.c
@@ -0,0 +1,17 @@
+
+#include "states.h"
+
+struct gameState stateTable[] = {
+    {*displayMainmenu, *eventsMainmenu},       /* STATE_MAINMENU */
+    {*displayNumplayers, *eventsNumplayers},   /* STATE_NUMPLAYERS */
+    {*displayCredits, *eventsCredits},         /* STATE_CREDITS */
+    {*displayRunninggame, *eventsRunninggame}, /* STATE_RUNNINGGAME */
+    {*displayRlyquit, *eventsRlyquit},         /* STATE_RLYQUIT */
+    {*exitGame, *exitGame}                     /* STATE_EXIT */
+};
+
+void exitGame() {
+  currentState = STATE_EXIT;
+}
+
+
diff --git a/src/states.h b/src/states.h
new file mode 100644
index 0000000..a931da6
--- /dev/null
+++ b/src/states.h
@@ -0,0 +1,34 @@
+
+#ifndef STATES_H
+#define STATES_H
+
+#include "config.h"
+
+// All possible game states are defined in config.h
+
+
+// A single game state
+struct gameState {
+  void(*drawFun)();
+  void(*handleEventsFun)();
+};
+
+struct gameState stateTable[MAX_STATES];
+
+// State Functions prototypes
+void displayMainmenu();
+void displayNumplayers();
+void displayCredits();
+void displayRunninggame();
+void displayRlyquit();
+
+void eventsMainmenu();
+void eventsNumplayers();
+void eventsCredits();
+void eventsRunninggame();
+void eventsRlyquit();
+
+void exitGame();
+
+#endif
+