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authorSilvan Jegen <s.jegen@gmail.com>2018-09-22 20:01:40 +0200
committerSilvan Jegen <s.jegen@gmail.com>2018-09-22 20:05:53 +0200
commit5d5bc3e446ee50601f98ca30d4f21172d6e75e29 (patch)
treeabdbe68d23373c095e2d50b2cd8f15af40dfdb65
Initial commit
-rwxr-xr-xbuild_linux.sh7
-rw-r--r--echidna_ai.c245
-rw-r--r--entities.pngbin0 -> 11676 bytes
-rw-r--r--failscreen_01.pngbin0 -> 29998 bytes
-rw-r--r--game.c203
-rw-r--r--gpl.txt674
-rw-r--r--helpscreen.c31
-rw-r--r--helpscreen.pngbin0 -> 51467 bytes
-rw-r--r--level.c236
-rw-r--r--main.c117
-rw-r--r--render.c138
-rw-r--r--tiles.pngbin0 -> 2618 bytes
-rw-r--r--titlescreen.pngbin0 -> 22328 bytes
-rw-r--r--winningscreen.pngbin0 -> 33319 bytes
14 files changed, 1651 insertions, 0 deletions
diff --git a/build_linux.sh b/build_linux.sh
new file mode 100755
index 0000000..1b2c8a8
--- /dev/null
+++ b/build_linux.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+CC=gcc
+FLAGS="-Wall $(sdl2-config --cflags --libs) -lSDL_image"
+
+arch="$(uname -m)"
+${CC} $FLAGS main.c -o "echidna_menace.linux_$arch"
diff --git a/echidna_ai.c b/echidna_ai.c
new file mode 100644
index 0000000..64759a4
--- /dev/null
+++ b/echidna_ai.c
@@ -0,0 +1,245 @@
+
+/* The echidna AI has three modes:
+ *
+ * MODE_HUNT
+ * The echidna tries to close the space between itself and the player
+ *
+ * MODE_FOLLOW_WALL
+ * The echidna has hit a wall and is now following it
+ *
+ * MODE_CORNER
+ * This mode makes the monster move around a corner after it has been following a wall
+ *
+ * See the developer documentation for more information about how this large algorithm works.
+ */
+
+// Give each of the modes a numerical value
+#define MODE_HUNT 1
+#define MODE_FOLLOW_WALL 2
+
+// The echidna structure is declared in 'level.c' so it can be loaded
+
+
+// is_square solid returns 1 if a square is not passable ( ie a wall or closed door )
+// and 0 if it is ( ie floor, button )
+int is_square_solid( struct level_struct *currentlevel, int xpos, int ypos )
+{
+
+ switch ( currentlevel->squares[ xpos ][ ypos ] )
+ {
+ case T_WALL: return 1;
+ case T_BLUE_DOOR_UP: return 1;
+ case T_YELL_DOOR_UP: return 1;
+ case T_RED_DOOR_UP: return 1;
+
+ // The default case occurs when none of the above are met
+ default: return 0; // ie the square is walkable on
+ }
+}
+
+// run_all_echidnaAI_onestep runs one 'step' of echidna AI for every echidna in a level
+void run_all_echidnaAI_onestep( struct level_struct *currentlevel )
+{
+ // Ieterate through each and every echinda
+ int ech_no; // Echidna number
+ for ( ech_no = 0; ech_no < 10; ech_no++ )
+ {
+ struct echidna *current_echidna = &currentlevel->echidnas[ech_no];
+
+
+ if ( current_echidna->this_echidna_exists == 1 )
+ {
+
+ // This echidna is alive and we can move it
+
+ // How the echidna is going to move, similiar to the player code;
+ signed int x = 0;
+ signed int y = 0;
+
+
+ /////////////////////////////////////////////////////////////////////////////////////////////// HUNT MODE
+ if ( current_echidna->mode == MODE_HUNT )
+ {
+ // Find the orthoganol ( x and y, not true or diagonal ) distances between the echidna and player
+ // NB abs() returns the absolute value of something, which fixes negative numbers by changing
+ // them to be position
+ int distx = abs( current_echidna->xpos - currentlevel->px );
+ int disty = abs( current_echidna->ypos - currentlevel->py );
+
+ if ( distx > disty )
+ {
+
+ // Now check whether the player is to the left or right of the echidna
+ if ( currentlevel->px > current_echidna->xpos )
+ {
+ // Echidna is left of player
+ x = 1;
+ }
+ else
+ {
+ // Echidna is right of player
+ x = -1;
+ }
+ }
+ else
+ {
+ // Is the player abov or below the echidna
+ if ( currentlevel->py > current_echidna->ypos )
+ {
+ // Echidna is below player
+ y = 1;
+ }
+ else
+ {
+ // Echidna is above player
+ y = -1;
+ }
+ }
+
+ // Now check if this is going to make the echidna try to walk into a wall
+ // If it will, change mode to MODE_FOLLOW_WALL
+ if ( is_square_solid( currentlevel, current_echidna->xpos + x, current_echidna->ypos + y ) == 1 )
+ {
+ current_echidna->mode = MODE_FOLLOW_WALL;
+
+ // Make a decision about which way to move
+ // This scheme ensures the echidna moves clockwise
+ current_echidna->move_x = 0;
+ current_echidna->move_y = 0;
+ if ( x == 1 ) current_echidna->move_y = 1;
+ else if ( x == -1 ) current_echidna->move_y = -1;
+ else if ( y == 1 ) current_echidna->move_x = -1;
+ else if ( y == -1 ) current_echidna->move_x = 1;
+
+ // Make sure the echidna checks the wall its following
+ // to see if it still exists
+ current_echidna->check_x = x;
+ current_echidna->check_y = y;
+ }
+ }
+
+ ///////////////////////////////////////////////////////////////////////////////////////////// FOLLOW WALL MODE
+ if ( current_echidna->mode == MODE_FOLLOW_WALL )
+ {
+
+ // Check the wall we are following
+ if ( is_square_solid( currentlevel, current_echidna->xpos + current_echidna->check_x, current_echidna->ypos + current_echidna->check_y ) == 1 )
+ {
+ // The wall is still there, so keep following it
+ x = current_echidna->move_x;
+ y = current_echidna->move_y;
+
+ // Check if a new wall is in the way
+ while ( is_square_solid( currentlevel, current_echidna->xpos + x, current_echidna->ypos + y ) == 1 )
+ {
+ // We need to follow another wall now. Same clockwise logic as before
+ current_echidna->check_x = x;
+ current_echidna->check_y = y;
+ if ( x == 1 ) { x = 0; y = 1; }
+ else if ( x == -1 ) { x = 0; y =-1; }
+ else if ( y == 1 ) { x =-1; y = 0; }
+ else if ( y == -1 ) { x = 1; y = 0; }
+ current_echidna->move_x = x;
+ current_echidna->move_y = y;
+ }
+ }
+ else
+ {
+ // The wall has gone, so immediately go around the corner
+ x = current_echidna->check_x;
+ y = current_echidna->check_y;
+
+
+ // And resume HUNT mode next time
+ current_echidna->mode = MODE_HUNT;
+ }
+ }
+
+ ////////////////////////////////////////////// MOVE THE ECHIDNA
+
+ // Move
+ current_echidna->xpos = current_echidna->xpos + x;
+ current_echidna->ypos = current_echidna->ypos + y;
+
+ // Check if we have moved ontop of an Echidna, and if so then move back to where we started
+ // ( it will appear as if we have not moved at all )
+
+ int target_num;
+ for ( target_num = 0; target_num < ech_no; target_num++ ) // Check all of the echidnas BEFORE the current one, so we can have right of way
+ {
+ struct echidna target_echidna = currentlevel->echidnas[target_num];
+ if ( target_echidna.this_echidna_exists == 1 )
+ {
+ if ( target_echidna.xpos == current_echidna->xpos && target_echidna.ypos == current_echidna->ypos )
+ {
+ // We have a clash, so move back to the original square
+ current_echidna->xpos = current_echidna->xpos - x;
+ current_echidna->ypos = current_echidna->ypos - y;
+ }
+ }
+ }
+ }
+ }
+}
+
+
+
+// Returns 1 if an echidna is in the same spot as the player
+int check_echidna_proximity( struct level_struct *currentlevel )
+{
+ // Ieterate through eacha and every echinda
+ int ech_no; // Echidna number
+
+
+ for ( ech_no = 0; ech_no < 10; ech_no++ )
+ {
+ struct echidna currentechidna = currentlevel->echidnas[ech_no];
+
+ // First make sure we are checking an echidna that ACTUALLY EXISTS
+ // Until I wrote this code to check that, I was mysteriously dieing halfway
+ // throught some levels. Fun :)
+ if ( currentechidna.this_echidna_exists == 1 )
+ {
+ if ( currentechidna.xpos == currentlevel->px && currentechidna.ypos == currentlevel->py ) // && means 'and'
+ {
+ // An echidna is atop a player
+ return 1;
+ }
+ }
+ }
+
+ // No echidna is atop the player
+ return 0;
+}
+
+// Echidnas are the onlt things that can toggler the red levers, and this loop checks to see if that need to happen
+void check_echidna_on_switches( struct level_struct *currentlevel )
+{
+ // Ieterate through each and every echinda
+ int ech_no; // Echidna number
+
+
+ for ( ech_no = 0; ech_no < 10; ech_no++ )
+ {
+ struct echidna currentechidna = currentlevel->echidnas[ech_no];
+
+ if ( currentechidna.this_echidna_exists == 1 )
+ {
+ // Get the square the echinda is standing on
+ char square = currentlevel->squares[ currentechidna.xpos ][ currentechidna.ypos ] ;
+
+ if ( square == T_RED_SWITCH_ON )
+ {
+ level_replace_tiles( currentlevel, T_RED_SWITCH_ON, T_RED_SWITCH_OFF ); // change ALL levers
+ level_replace_tiles( currentlevel, T_RED_DOOR_UP, T_RED_DOOR_DOWN ); // open all red doors
+ }
+ else if ( square == T_RED_SWITCH_OFF )
+ {
+ level_replace_tiles( currentlevel, T_RED_SWITCH_OFF, T_RED_SWITCH_ON ); // change ALL levers
+ level_replace_tiles( currentlevel, T_RED_DOOR_DOWN, T_RED_DOOR_UP ); // close all red doors
+ }
+ }
+ }
+}
+
+
diff --git a/entities.png b/entities.png
new file mode 100644
index 0000000..f1b4462
--- /dev/null
+++ b/entities.png
Binary files differ
diff --git a/failscreen_01.png b/failscreen_01.png
new file mode 100644
index 0000000..0c58261
--- /dev/null
+++ b/failscreen_01.png
Binary files differ
diff --git a/game.c b/game.c
new file mode 100644
index 0000000..eaac7f9
--- /dev/null
+++ b/game.c
@@ -0,0 +1,203 @@
+#define PLAYER_IS_OK 1
+#define PLAYER_IS_DEAD 2
+#define PLAYER_HAS_WON 3
+
+
+
+// player_action moves the player
+// It returns one of the three PLAYER_ define values ( top of this file )
+int player_action( signed int xdiff, signed int ydiff, struct level_struct *currentlevel )
+{
+ // Find the tile the player moved into/onto using the player's current position
+ int newx = currentlevel->px + xdiff;
+ int newy = currentlevel->py + ydiff;
+
+ // Cycle through the player's faces
+ currentlevel->player_face++;
+ if ( currentlevel->player_face == 4 ) currentlevel->player_face = 0;
+
+ // Check to make sure these directions are not solid ( ie walls )
+ // and also to see if they are interactive ( ie buttons )
+ char targetsquare = currentlevel->squares[newx][newy];
+
+ if ( targetsquare == T_WALL || targetsquare == T_YELL_DOOR_UP || targetsquare == T_BLUE_DOOR_UP || targetsquare == T_RED_DOOR_UP ) // remember '||' means 'OR'
+ {
+ // Cannot move, so do nothing
+ return PLAYER_IS_OK;
+ }
+ else
+ {
+ // Move onto the new square
+ currentlevel->px = newx;
+ currentlevel->py = newy;
+
+ // Check to see if the new square is interactive ( ie a button )
+
+ switch ( targetsquare )
+ {
+ case T_BLUE_BUTT_UP: // Blue button
+ // Change the button to be depressed
+ currentlevel->squares[newx][newy] = T_BLUE_BUTT_DOWN;
+ // Change all blue doors in the level to be unlocked
+ level_replace_tiles( currentlevel, T_BLUE_DOOR_UP, T_BLUE_DOOR_DOWN );
+ return PLAYER_IS_OK;
+
+ case T_YELL_BUTT_UP: // Yellow button
+ // Change the button to be depressed
+ currentlevel->squares[newx][newy] = T_YELL_BUTT_DOWN;
+ // Change all blue doors in the level to be unlocked
+ level_replace_tiles( currentlevel, T_YELL_DOOR_UP, T_YELL_DOOR_DOWN );
+ return PLAYER_IS_OK;
+
+ case T_EXIT:
+ // User is on the exit
+ return PLAYER_HAS_WON;
+
+ case T_SPIKE:
+ // The daft player walked onto spikes
+ return PLAYER_IS_DEAD;
+
+
+
+ default:
+ // This has to be here to stop the compiler complaining
+ // Basically the 'default' is run if no other case is run
+ return PLAYER_IS_OK;
+
+ }
+ }
+
+ // Code should never reach this point
+ // The return line here is just to make the compiler happy
+
+ return 0;
+
+}
+
+
+int play_level( struct level_struct *currentlevel, SDL_Surface * surf_screen )
+{
+ // Loop until the user completes the level
+ int player_status = PLAYER_IS_OK;
+
+ while ( player_status == PLAYER_IS_OK )
+ {
+ SDL_Event userinput;
+
+ // WaitEvent is like PollEvent, but instead we pause the program's
+ // execution until we get input
+ SDL_WaitEvent( &userinput );
+ render( currentlevel, surf_screen );
+
+ // Player movement
+ signed int y, x;
+
+ if ( userinput.type == SDL_KEYDOWN )
+ {
+ switch ( userinput.key.keysym.sym )
+ {
+ case SDLK_UP:
+ x = 0;
+ y = -1;
+ break;
+
+ case SDLK_DOWN:
+ x = 0;
+ y = 1;
+ break;
+
+ case SDLK_RIGHT:
+ x = 1;
+ y = 0;
+ break;
+
+ case SDLK_LEFT:
+ x = -1;
+ y = 0;
+ break;
+
+ case SDLK_q:
+ exit(0); // Quit the game
+ break;
+
+ case SDLK_h:
+ // View the help screen
+ help( surf_screen );
+ x = 0;
+ y = 0;
+
+ default:
+ // The user hits any other key
+ // ( do nothing )
+ x = 0;
+ y = 0;
+ break;
+ }
+
+ // Now move the player
+ player_status = player_action( x, y, currentlevel );
+
+ // Move all of the echidnas
+ run_all_echidnaAI_onestep( currentlevel );
+ // And make sure we open/close red doors if any of them are stepping on red levers
+ check_echidna_on_switches( currentlevel );
+
+ // Check to see if the player has run into an echidna
+ if ( check_echidna_proximity( currentlevel ) == 1 ) player_status = PLAYER_IS_DEAD;
+
+ // Show a losing screen if applicable
+ if (player_status == PLAYER_IS_DEAD) render_a_losingscreen( currentlevel, surf_screen);
+ }
+
+ }
+
+
+
+ // The code running play_level needs to know if too advance to the next level
+ // or just repeat the current one ( if the player has died )
+ return player_status;
+}
+
+void game_loop( SDL_Surface * surf_screen )
+{
+
+ struct level_struct currentlevel;
+ level_load_resources( &currentlevel ); // load pixmaps
+
+ // Initialise initial player face
+ currentlevel.player_face = 2;
+
+ int level_number; // Level's number in progression of game, also used as the filename to load the level from
+
+ // Run through each of the levels
+
+ for ( level_number = 2; level_number <= 10; level_number++ )
+ {
+ int level_state = PLAYER_IS_OK;
+
+ while ( level_state != PLAYER_HAS_WON )
+ {
+ // Load the level
+ level_load( level_number, &currentlevel );
+
+ // Set the player's new position
+ currentlevel.px = currentlevel.sx;
+ currentlevel.py = currentlevel.sy;
+
+ // Main game loop
+ level_state = play_level( &currentlevel, surf_screen );
+
+
+ }
+ // When the game loop ends, then the user has successfully completed the level, and we can move on
+ }
+
+ // The user has now completed all of the game
+ // Show them the winning screen
+ SDL_BlitSurface( currentlevel.surf_winning_screen, NULL, surf_screen, NULL);
+ SDL_Flip( surf_screen );
+
+ SDL_Delay(20 * 1000); // 20 * 1000msecs = 20 seconds
+
+ // Once this function ends, we return to the menu
+}
diff --git a/gpl.txt b/gpl.txt
new file mode 100644
index 0000000..818433e
--- /dev/null
+++ b/gpl.txt
@@ -0,0 +1,674 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
+ The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+
+ The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works. By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users. We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors. You can apply it to
+your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
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+
+ Nothing in this License shall be construed as excluding or limiting
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+
+ 12. No Surrender of Others' Freedom.
+
+ If conditions are imposed on you (whether by court order, agreement or
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+
+ 13. Use with the GNU Affero General Public License.
+
+ Notwithstanding any other provision of this License, you have
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+
+ 14. Revised Versions of this License.
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+
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+
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+
+ 15. Disclaimer of Warranty.
+
+ THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
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+ 16. Limitation of Liability.
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+SUCH DAMAGES.
+
+ 17. Interpretation of Sections 15 and 16.
+
+ If the disclaimer of warranty and limitation of liability provided
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+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+ <one line to give the program's name and a brief idea of what it does.>
+ Copyright (C) <year> <name of author>
+
+ 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
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+ If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+ <program> Copyright (C) <year> <name of author>
+ This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+ You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<http://www.gnu.org/licenses/>.
+
+ The GNU General Public License does not permit incorporating your program
+into proprietary programs. If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License. But first, please read
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.
diff --git a/helpscreen.c b/helpscreen.c
new file mode 100644
index 0000000..dbbbce0
--- /dev/null
+++ b/helpscreen.c
@@ -0,0 +1,31 @@
+
+void help( SDL_Surface * surf_screen )
+{
+ // Load help image
+ SDL_Surface *surf_help = IMG_Load( "helpscreen.png" );
+
+ // Draw this image onto screen
+ SDL_BlitSurface( surf_help, NULL, surf_screen, NULL);
+ SDL_Flip( surf_screen );
+
+ // now free the memory we used to draw this image
+ free( surf_help );
+
+ // Now wait until the user presses a key
+ SDL_Event event;
+ int waiting_for_user = 1;
+
+ while ( waiting_for_user )
+ {
+ while ( SDL_PollEvent( &event ) )
+ {
+ if ( event.type == SDL_KEYDOWN )
+ {
+ waiting_for_user = 0;
+ break;
+ }
+ }
+ }
+}
+
+
diff --git a/helpscreen.png b/helpscreen.png
new file mode 100644
index 0000000..283d6e9
--- /dev/null
+++ b/helpscreen.png
Binary files differ
diff --git a/level.c b/level.c
new file mode 100644
index 0000000..bfa3ec1
--- /dev/null
+++ b/level.c
@@ -0,0 +1,236 @@
+/*
+ * Each of the different types of tile in the levels are numbered
+ * These are also the values used in the level text files
+ *
+ * All of the level tiles are stored in one image, hence the 'Rows'
+ * below are literally the rows there are positioned in the image.
+ * Have a look at tiles.png in the game's folder to see them all.
+ */
+
+// Row 1 - main squares
+#define T_WALL 0
+#define T_FLOOR 1
+#define T_SPIKE 2
+#define T_EXIT 3
+// Row two - blue button related
+#define T_BLUE_BUTT_UP 4 // unpressed button
+#define T_BLUE_BUTT_DOWN 5 // depressed button
+#define T_BLUE_DOOR_UP 6 // door unlocked by a button
+#define T_BLUE_DOOR_DOWN 7 // door locked and impassible
+// Row three - yellow button related
+#define T_YELL_BUTT_UP 8
+#define T_YELL_BUTT_DOWN 9
+#define T_YELL_DOOR_UP 10
+#define T_YELL_DOOR_DOWN 11
+// Row four - red lever/switch related
+#define T_RED_SWITCH_ON 12
+#define T_RED_SWITCH_OFF 13
+#define T_RED_DOOR_UP 14
+#define T_RED_DOOR_DOWN 15
+
+// An echidna is one of the monsters
+// The structure is define here in level.c so it can be loaded from the level files
+struct echidna
+{
+ int xpos, ypos; // Position on map
+ int face; // Which of the echidna pictures to use
+
+ int mode; // As described at the top of the document
+
+ int this_echidna_exists; // When this is equal to 1, the echidna is alive and on the level
+
+ // These movement directions are used in the AI code
+ signed int move_x;
+ signed int move_y;
+ // ditto here
+ signed int check_x;
+ signed int check_y;
+
+};
+
+/* The level structure is passed to the rendering module, so everything that needs to be seen
+ * on-screen is also stored here as well
+ *
+ * Eg:
+ * - player position
+ * - resource locations ( graphics )
+ */
+struct level_struct
+{
+
+ char squares[SCREEN_WIDTH_SQUARES][SCREEN_HEIGHT_SQUARES]; // Squares of the level
+
+ // Player details
+ int player_face; // Picture number ( player has 4 different looks )
+ int px, py; // Player X and Y position, on the tiles
+ int sx, sy; // Player X and Y starting positions
+
+ // Resources
+ SDL_Surface * surf_entities; // Player and echidna pictures
+ SDL_Surface * surf_tiles; // Level tiles/squares
+
+ // A various selection of losing screens
+ SDL_Surface * surf_losingscreens[5];
+
+ // The screen to display when the game ends
+ SDL_Surface * surf_winning_screen;
+
+ // Up to ten echidnas
+ struct echidna echidnas[10];
+
+};
+
+
+
+/* eat_until_newline will 'eat' one character at a time from a file until it detects it has
+ * finished a line, then stops. This is used to make sure a line of text in the level files
+ * has been finished before we move on to the next */
+void eat_until_newline( FILE *currentfile )
+{
+ char letter='a';
+ while ( letter != '\n' ) // The '\n' represents the invisible line ending characters (either CRLF or LF)
+ {
+ // Every time a character is read, the current position inside of the file is also moved forward
+ // one character
+ letter = fgetc( currentfile );
+ }
+}
+
+
+
+// Load the graphics used in levels
+void level_load_resources( struct level_struct *level )
+{
+ // Load the images for things into their own 'surfaces'
+ level->surf_entities = IMG_Load( "entities.png" );
+ level->surf_tiles = IMG_Load( "tiles.png" );
+
+ // Do the same for the losing screens
+ level->surf_losingscreens[0] = IMG_Load("failscreen_01.png");
+ level->surf_winning_screen = IMG_Load("winningscreen.png");
+
+}
+
+
+
+// level_load will load a level from a text file into a level_struct
+void level_load( int level_number, struct level_struct *level )
+{
+
+ // Create the level's actual filename from its number
+ char levelname[20];
+ sprintf( levelname, "level_%02d.level", level_number );
+
+ // Attempt to open the file
+ FILE *levelfile = fopen( levelname, "r"); // r = reading mode
+
+
+ // Check if the file loaded, quit program if this has failed
+ if ( levelfile == NULL )
+ {
+ // For some reason the file cannot be accessed
+ // This could be because it does not exist or we don't have permission to open it
+
+ fprintf(stderr, "Error: Could not open level file %d, perhaps it is somewhere else or does not exist?\n", level_number );
+ fprintf(stderr, "Exiting... \n\n" );
+
+ exit(1);
+ }
+
+ // First we need to skip the first line of the file, which is dedicated to title, author etc information
+ eat_until_newline( levelfile );
+
+ // The second line contains the starting position of the player
+ fscanf( levelfile, "%d %d", &level->sx, &level->sy );
+ eat_until_newline(levelfile);
+
+ printf("Loading level %s, player at position: %d %d\n", levelname, level->sx, level->sy );
+
+ /* Ieterate through the file and load the squares into the level's structure
+ * Each row/line in the file represents a row of squares in the level
+ * Each square is represented in the rows by a number from 0 to 255
+ * Open up one of the level files with a text editor to study its structure further
+ */
+
+ /* WARNING: This code assumes the file is structured correctly in the first place!
+ * The game will behave in an unexpected manner if the level files are not perfect!
+ */
+
+ int row, column; // Current position
+
+ for ( row=0; row < SCREEN_HEIGHT_SQUARES; row++ )
+ {
+ for ( column=0; column < SCREEN_WIDTH_SQUARES; column++ )
+ {
+ /* we read each two letter number into a three letter character array ( string )
+ * the third character is used to represent the end or 'termination' of the string
+ */
+ char tempstring[3];
+ fgets( tempstring, 3, levelfile );
+
+ // atoi() is a standard C function used to covert a string of numbers in character
+ // form into an actual number ( integer )
+ level->squares[column][row] = atoi( tempstring );
+ }
+
+ // We need to make sure that we finish the current line of numbers/characters in the
+ // level file, and are up to the next, else bad things may happen
+ eat_until_newline( levelfile );
+ }
+
+ /* Now start loading the echidna positions
+ * Every line after the main level tile body is an echidna
+ * The format for each line is:
+ * xpos ypos face
+ * Where each of them is a number, face being a number from 0 to 3 choosing the particular face of the echidna
+ */
+
+ int ech_no; // Echidna number
+
+ for ( ech_no = 0; ech_no < 10; ech_no++ )
+ {
+ level->echidnas[ech_no].this_echidna_exists = 0;
+ level->echidnas[ech_no].mode = 1; // Start in hunt mode
+
+ // Now load the echidna values in
+ if ( fscanf( levelfile, "%d %d %d", &level->echidnas[ech_no].xpos, &level->echidnas[ech_no].ypos, &level->echidnas[ech_no].face ) == 3 )
+ {
+ // When fscanf returns a number other than '3' ( which is how many numbers we are reading per line )
+ // we know there are no more lines in the file and we should stop, hence the == 3
+ level->echidnas[ech_no].this_echidna_exists = 1;
+
+ printf("Echidna loaded at x:%d y:%d\n", level->echidnas[ech_no].xpos, level->echidnas[ech_no].ypos );
+ }
+ }
+
+
+}
+
+
+
+// Replace every tile in the level of firsttype with secondtype
+// Useful for eg opening doors
+void level_replace_tiles( struct level_struct *currentlevel, char firsttype, char secondtype )
+{
+ int tilex, tiley; // Where we are up to
+
+ for ( tiley=0; tiley < SCREEN_WIDTH_SQUARES; tiley++ )
+ {
+ for ( tilex=0; tilex < SCREEN_WIDTH_SQUARES; tilex++ )
+ {
+ if ( currentlevel->squares[tilex][tiley] == firsttype ) currentlevel->squares[tilex][tiley] = secondtype;
+ }
+ }
+}
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..5561051
--- /dev/null
+++ b/main.c
@@ -0,0 +1,117 @@
+// Standard libraries ( not written by me )
+#include <stdio.h>
+#include <string.h>
+
+// SDL libraries ( not written by me )
+#include "SDL2/SDL.h"
+#include "SDL2/SDL_image.h"
+
+#ifdef __WIN32__
+ // Work around a TCC<->SDL bug regarding the redefintion of main.
+ // Note: the error messages from TCC make no sense
+ #undef main
+#endif
+
+
+// Window dimensions
+#define SCREEN_WIDTH 640
+#define SCREEN_HEIGHT 480
+#define TILE_SIZE 32 // Width and height of 'squares' in the game
+
+#define SCREEN_WIDTH_SQUARES SCREEN_WIDTH / TILE_SIZE
+#define SCREEN_HEIGHT_SQUARES SCREEN_HEIGHT / TILE_SIZE
+
+// Modules of the game I have written ( in directory with this source file )
+#include "level.c" // Level structures, loading, other levely stuff
+#include "helpscreen.c" // Help-screen code
+#include "echidna_ai.c" // Echidna movement A
+#include "render.c" // Normal in-game rendering
+#include "game.c" // Normal in-game code
+
+/* error_sdl is called when SDL 'throws' an error
+ * SDL can throw an error if the computer is for example incapable of displaying
+ * the game, because it is too old ( ie made before the year 1998 ) */
+void error_sdl( char* reason )
+{
+ // Print the error message and then close the game
+ fprintf( stderr, "Error (SDL): %s: %s\n", reason, SDL_GetError() );
+ exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+ /// Initialisation
+
+ /* First we need to tell SDL to create a window. A 'surface' is created called surf_screen,
+ * 'surfaces' are simply images of what we see on-screen.
+ *
+ * To make things appear on the screen, I copy ('blit') images onto this surface at different locations
+ */
+
+ // Initialise SDL
+ printf("Initialising SDL... ");
+ if ( SDL_Init( SDL_INIT_VIDEO ) == -1 ) error_sdl("Could not initialise SDL");
+ atexit(SDL_Quit);
+
+ // Set surf_screen
+ SDL_Surface* surf_screen = NULL;
+ SDL_Window * sdlWindow = SDL_CreateWindow("EchidneaMenace", SDL_WINDOWPOS_UNDEFINED,
+ SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_FULLSCREEN | SDL_WINDOW_OPENGL );
+ if ( surf_screen == NULL ) error_sdl("Could not set videomode");
+ SDL_Renderer *renderer = SDL_CreateRenderer(sdlWindow, -1, 0);
+
+ printf("done\n");
+
+
+ /// Menu
+ printf(" ==== Entered menu\n");
+
+ // Events are variables used to store user input
+ SDL_Event menuevent;
+ // Load the menu graphic into memory
+ SDL_Surface *surf_title = IMG_Load( "titlescreen.png" );
+
+
+ /* We loop the menu continously for a number of reasons:
+ * 1) To make sure we capture and respond to user input
+ * 2) To continue redrawing the menu graphic.
+ *
+ * If we did not do number 2 then the window would appear blank if minimised
+ * and then de-minimised again, amongst other situations
+ */
+ while ( 1 )
+ {
+ SDL_BlitSurface( surf_title, NULL, surf_screen, NULL); // Draw menu
+ SDL_Flip( surf_screen ); // Update screen
+
+ // The while statement attempts to go through every key the user has pressed
+ // it stops when the user has not pressed any more keys
+ // this is useful incase the user presses keys fast or multiple at once
+ while ( SDL_PollEvent( &menuevent ) )
+ {
+ if ( menuevent.type == SDL_KEYDOWN )
+ {
+ // Menu choice selection
+ if ( menuevent.key.keysym.sym == SDLK_p ) game_loop( surf_screen );
+ else if ( menuevent.key.keysym.sym == SDLK_h ) help( surf_screen );
+ else if ( menuevent.key.keysym.sym == SDLK_q || menuevent.key.keysym.sym == SDLK_ESCAPE ) exit(0);
+ }
+ }
+
+ // If we do not 'wait' or sleep in every ieteration of the loop
+ // the game will loop as fast as it can, utilising 100% of the CPU
+ SDL_Delay( 200 );
+ }
+
+
+
+
+ /* Technically the computer will never reach this point, because the while statement
+ * above will run forever until the user quits the game.
+ *
+ * The 'return' statement is still written here so the compiler does not complain
+ */
+
+ return 0;
+
+}
diff --git a/render.c b/render.c
new file mode 100644
index 0000000..8a91b59
--- /dev/null
+++ b/render.c
@@ -0,0 +1,138 @@
+
+
+/* Different areas of the entities.png image contain different things.
+ * For example the first row are player pictures whilst the second are
+ * of echidnas.
+ *
+ * 'SDL_Rect's are simple structures containing the location and size
+ * of these individual pictures inside of the larger 'entities.png'
+ *
+ * The same thing is done for the different level graphics
+ */
+
+// Sets the SDL_Rect * crop to the location of specified echinida
+// ( there are four echidna pictures, so which_echidna can be 0-3)
+void get_pixmap_echidna(int which_echidna, SDL_Rect * crop )
+{
+ crop->x = which_echidna * TILE_SIZE;
+ crop->y = 1 * TILE_SIZE; // all echidnas are in the second row
+}
+
+// Same as above, but for the player (lemon)
+void get_pixmap_lemon(int which_lemon, SDL_Rect * crop )
+{
+ crop->x = which_lemon * TILE_SIZE;
+ crop->y = 0; // all lemons are in the first row
+}
+
+// Getting the rectangle for level tiles is a little harder, as they are spread
+// across multiple rows. Otherwise this does similarly to above modules
+void get_pixmap_level( char number, SDL_Rect * crop )
+{
+ int row, column;
+
+ row = 0;
+ column = (int)number;
+
+ // Compensate for the fact these pictures span multiple rows
+ while ( column >= 4 )
+ {
+ column = column - 4;
+ row++; // add one to row's value
+ }
+
+ crop->x = column * TILE_SIZE;
+ crop->y = row * TILE_SIZE;
+}
+
+
+
+
+// render() paints everything onto the screen when called
+void render( struct level_struct *currentlevel, SDL_Surface * surf_screen )
+{
+ /* The picture on-screen is made in three steps:
+ * 1) Draw the level onto the screen surface
+ * 2) Draw the player and echidnas ontop of this
+ * 3) 'flip' the screen, so the changes can be seen
+ */
+
+ SDL_Rect destination; // where the image is going to be painted to on-screen
+ SDL_Rect pixmap_crop; // where the tile image is on the source image
+ destination.w = TILE_SIZE;
+ destination.h = TILE_SIZE;
+ pixmap_crop.w = TILE_SIZE;
+ pixmap_crop.h = TILE_SIZE;
+
+
+ /// Level drawing
+
+ // ieterate through each square of the level, drawing the appropriate
+ // pictures for each onto the screen
+
+
+ int tilex, tiley; // Where we are up to
+
+ for ( tiley=0; tiley < SCREEN_WIDTH_SQUARES; tiley++ )
+ {
+ for ( tilex=0; tilex < SCREEN_WIDTH_SQUARES; tilex++ )
+ {
+ /// Determine which section of the entities image we are going to use
+ get_pixmap_level( currentlevel->squares[tilex][tiley] , &pixmap_crop );
+ // remember that the currentlevel structure contains the array of
+ // level squares/tiles
+
+ /// Determine where we are going to draw this image on-screen
+ destination.x = tilex * TILE_SIZE;
+ destination.y = tiley * TILE_SIZE;
+
+ /// Draw this tile onto the screen
+ SDL_BlitSurface ( currentlevel->surf_tiles, &pixmap_crop, surf_screen, &destination );
+ }
+ }
+
+ /// Entity drawing
+ // First of all the character
+ get_pixmap_lemon( currentlevel->player_face, &pixmap_crop );
+ destination.x = currentlevel->px * TILE_SIZE;
+ destination.y = currentlevel->py * TILE_SIZE;
+
+ // Draw onto screen
+ SDL_BlitSurface ( currentlevel->surf_entities, &pixmap_crop, surf_screen, &destination );
+
+ // Now draw all of the echidnas
+ int ech_no; // Echidna number
+
+ for ( ech_no = 0; ech_no < 10; ech_no++ )
+ {
+ struct echidna current_echidna = currentlevel->echidnas[ech_no];
+
+ if ( current_echidna.this_echidna_exists == 1 )
+ {
+ // This echidnas exists and is alive
+
+ // Get its location and face
+ get_pixmap_echidna( current_echidna.face, &pixmap_crop );
+ destination.x = current_echidna.xpos * TILE_SIZE;
+ destination.y = current_echidna.ypos * TILE_SIZE;
+
+ // Draw it onscreen
+ SDL_BlitSurface ( currentlevel->surf_entities, &pixmap_crop, surf_screen, &destination );
+ }
+
+ }
+
+ /// Flip screen, so everything we have 'blitted' can now be seen
+ SDL_Flip( surf_screen );
+
+}
+
+void render_a_losingscreen( struct level_struct *currentlevel, SDL_Surface * surf_screen )
+{
+ // Render a losing screen
+ SDL_BlitSurface ( currentlevel->surf_losingscreens[0], NULL, surf_screen, NULL );
+ SDL_Flip( surf_screen );
+
+ // Wait a second so the user can see the losing screen
+ SDL_Delay(500);
+}
diff --git a/tiles.png b/tiles.png
new file mode 100644
index 0000000..8de19a6
--- /dev/null
+++ b/tiles.png
Binary files differ
diff --git a/titlescreen.png b/titlescreen.png
new file mode 100644
index 0000000..36dbff5
--- /dev/null
+++ b/titlescreen.png
Binary files differ
diff --git a/winningscreen.png b/winningscreen.png
new file mode 100644
index 0000000..d1e8de4
--- /dev/null
+++ b/winningscreen.png
Binary files differ