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Getting Started: Getting Started: C-Revisions and C-Revisions and Introduction to GraphicsIntroduction to Graphics

• Next: Simulation Essentials, Memory Handling

Topics for Discussion

Elements of the Tank Game

Compiling your program

Simple Animation

Double-buffering technique

Keyboard handling

Mouse handling

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Demo

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Tank GameTank Game

Elements of the Game

Graphics Engine

Keyboard & mouse control

Physics Engine

Dynamic Memory handling

Objects: Tank, Alien, Bomb, Bullet, Wall, Ledge

Transformation Equations, Zooming features

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Trigonometric Equations

Demo

• C:\Core\Massey Papers\159234\Animation-2008-v.4.0

• C:\Core\Massey Papers\159234\Bomb-v.1.0

• C:\Core\Massey Papers\159234\Bomb-v.11.0

• C:\Core\Massey Papers\159234\TankGame-2008-v.1.0

• C:\Core\Massey Papers\159234\Assignments\Samples\A1-06193242-Sample\Tank 2.0

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Why resort to writing codes using the Why resort to writing codes using the Object-Oriented approach?Object-Oriented approach?

What can you notice here?What can you notice here?

if(clock() > detonationTime){ for(int i=0; i < count; i++){

//Note: append Tank's x and y-components

Wx = Xdev(WBound,DBound,x(obj[i].t,obj[i].vO, obj[i].theta) + TankX); Wy = Ydev(WBound,DBound,y(obj[i].t,obj[i].vO, obj[i].theta) + TankY);

setlinestyle(SOLID_LINE, 0, 1);

fillellipse(Wx,Wy,Xdev(WBound,DBound,3.0),Xdev(WBound,DBound,3.0)); obj[i].t=obj[i].t + obj[i].tInc; } t=t+tinc;}

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What about here?What about here?

for(int i=0; i < numOfBombs; i++){

b[i].activate();

b[i].tick(tfm);

b[i].draw(tfm);

}

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C-Programming RevisionsC-Programming Revisions

C-LANGUAGE STRUCTUREC-LANGUAGE STRUCTURE

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/* include statements */#include <stdio.h>#include <string.h>

/* define statements */#define MAX 2000

/* function prototypes */void subfunc(int argument);

/* global variables */int i, j;char c;float x,y;char s[80];

/* functions */void subfunc(int argument) { int i; /* local variables */ statements...}

/* main program */int main() { statements...}

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Compiling your Program

MAKEFILE (for JFEJFE)

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MyProg.exe : MyProg.o graphics.o gcc -wl,-s -o MyProg.exe MyProg.o graphics.o

MyProg.o : MyProg.cpp graphics.h gcc -c -fpermissive -fconserve-space MyProg.cpp

graphics.o : graphics.cpp graphics.hgcc -c -fpermissive -fconserve-space graphics.cpp

Should start with a tab This is the minimum requirement for compilation.

Turn on all the warning messages possible

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Graphics Project

WORKSPACE (JFE)

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MYPROG.CPPGRAPHICS.CPPGRAPHICS.HMAKEFILE

GAME.WSP

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Compiling your Program

MAKEFILE (for scitescite)

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MyProg.exe : MyProg.o graphics.o g++ g++ -wl,-s -o MyProg.exe MyProg.o graphics.o

MyProg.o : MyProg.cpp graphics.h g++ g++ -c -fpermissive -fconserve-space MyProg.cpp

graphics.o : graphics.cpp graphics.hg++ g++ -c -fpermissive -fconserve-space graphics.cpp

This is the minimum requirement for compilation.

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Makefile

graphics.cpp

graphics.h

MyProg.cpp

All must reside in the same folder

It’s better to put classes in separate files.

physics.cpp

physics.h

The cppcpp file will include the function Implementations, while the header file (*.h*.h) willinclude the function prototypes and the classdefinition.

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Incorporating more files...

MAKEFILE (for scite)

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MyProg.exe : MyProg.o transform.o fuzzylogic.o physics.o bomb.o graphics.o g++ -Wl,-s -o MyProg.exe MyProg.o transform.o fuzzylogic.o physics.o bomb.o graphics.o

MyProg.o : MyProg.cpp graphics.h transform.h fuzzylogic.h bomb.h gameDef.hg++ -c -fpermissive -fconserve-space MyProg.cpp

transform.o : transform.cpp transform.hg++ -c -fpermissive -fconserve-space transform.cpp

fuzzylogic.o : fuzzylogic.cpp fuzzylogic.hg++ -c -fpermissive -fconserve-space fuzzylogic.cpp

physics.o : physics.cpp physics.hg++ -c -fpermissive -fconserve-space physics.cpp

bomb.o : bomb.cpp bomb.hg++ -c -fpermissive -fconserve-space bomb.cpp

graphics.o : graphics.cpp graphics.hg++ -c -fpermissive -fconserve-space graphics.cpp

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C-Programming RevisionsC-Programming Revisions

INITIALIZING GRAPHICSINITIALIZING GRAPHICS

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#include <windows.h>#include <stdio.h>#include <math.h>#include <time.h>#include "graphics.h"

int main(void){

srand(time(NULL)); // Seed the random number generatorint GraphDriver=0,GraphMode=0;initgraph(&GraphDriver, &GraphMode, "", 1280, 1024 );

TankGame(); //start the game – this is user-defined functionreturn 0;

}

User-defined, take note of the double quotes.

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Simple AnimationSimple Animation

Single Page Animation (Single Page Animation (flickery!flickery!))

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void SinglePage(){ int i; int x,y;

cleardevice(); y=getmaxy()/2; while( (GetAsyncKeyState(VK_ESCAPE))==0 ) for(x=0;x<getmaxx();x++) { if(GetAsyncKeyState(VK_ESCAPE) != 0) break; setactivepage(0); cleardevice(); setfillstyle(SOLID_FILL,RED); fillellipse(x,y,12,12); rectangle(x,y+(getmaxy()/12),x+100,y+(getmaxy()/11)); settextjustify(CENTER_TEXT, CENTER_TEXT); settextstyle(TRIPLEX_FONT, HORIZ_DIR, 4); outtextxy(getmaxx()/2,getmaxy()/8,"PAGE 0"); } }

Check if the ESC key has been pressed

Demo

• C:\Core\Massey Papers\159234\TankGame-2008-v.1.0

• See SinglePage and double buffering See SinglePage and double buffering animationsanimations

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Simple AnimationSimple Animation

Double-buffering Animation (Double-buffering Animation (flicker-free!flicker-free!))

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void MultiplePages(){ int i, x, y; bool PageFlag=TRUE; setactivepage(1); cleardevice(); outtext("PAGE 1"); setvisualpage(1); y=getmaxy()/2; while( (GetAsyncKeyState(VK_ESCAPE))==0 ) for(x=0;x<getmaxx();x++) { if(GetAsyncKeyState(VK_ESCAPE) != 0) break; if (PageFlag) { setactivepage(0); cleardevice(); setfillstyle(SOLID_FILL,RED); fillellipse(x,y,12,12); rectangle(x,y+(getmaxy()/12),x+100,y+(getmaxy()/11)); settextjustify(CENTER_TEXT, CENTER_TEXT); settextstyle(TRIPLEX_FONT, HORIZ_DIR, 4); outtextxy(getmaxx()/2,getmaxy()/8,"PAGE 0"); setvisualpage(0); }

Continued...Continued...

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C-Programming RevisionsC-Programming Revisions

Double-buffering Animation (Double-buffering Animation (flicker-free!flicker-free!))

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void MultiplePages(){ ... while( (GetAsyncKeyState(VK_ESCAPE))==0 ) for(x=0;x<getmaxx();x++) { if(GetAsyncKeyState(VK_ESCAPE) != 0) break; if (PageFlag) { ... } else { setactivepage(1); cleardevice(); setfillstyle(SOLID_FILL,RED); fillellipse(x,y,12,12); rectangle(x,y+(getmaxy()/12),x+100,y+(getmaxy()/11)); settextjustify(CENTER_TEXT, CENTER_TEXT); settextstyle(TRIPLEX_FONT, HORIZ_DIR, 4); outtextxy(getmaxx()/2,getmaxy()/8,"PAGE 1"); setvisualpage(1); } if(mousedown()) { } PageFlag=!PageFlag; } }

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Graphics Functions

void cleardevice (void);

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cleardevice erases (that is, fills with the current background color) the entire graphics screen and moves the CP (current position) to home (0,0).

e.g. 1280 x 1024 pixels

Device System of Coordinates

+x

+y

0

(XDevice,YDevice)

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Maximum Boundariesint getmaxx (void); int getmaxy (void);

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outtextxy(getmaxx()/2, getmaxy()/2, “Graphics");

(getmaxx(), getmaxy())

(0,0)

Graphics

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Graphics Functions

DISPLAYING TEXT

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setcolor(YELLOW);settextstyle(DEFAULT_FONT, HORIZ_DIR, 3);settextjustify(CENTER_TEXT, CENTER_TEXT);outtextxy(200, 300, “Graphics");

See graphics.h for more options

Demo

• C:\Core\Massey Papers\159234\TankGame-2008-v.1.0

• See GraphicsDemo()GraphicsDemo()

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Graphics Functions

DISPLAYING TEXT

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char mx[80];float N;

sprintf(mx,"%d",mousecurrentx());moveto(105, 224);outtext(mx);

N=4.5;sprintf(mx,"%3.2f", N);outtextxy(100, 250, mx);

Get mouse current x-position

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Graphics Functions

DISPLAYING TEXT

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void settextstyle (int font, int direction, int charsize);

Name Value    Description

DEFAULT_FONT 0 8x8 bit-mapped font

TRIPLEX_FONT 1 Stroked triplex font

SMALL_FONT 2 Stroked small font

SANS_SERIF_FONT 3 Stroked sans-serif font

GOTHIC_FONT 4 Stroked gothic font

SCRIPT_FONT 5 Stroked script font

SIMPLEX_FONT 6 Stroked triplex script font

TRIPLEX_SCR_FONT    7 Stroked triplex script font

COMPLEX_FONT 8 Stroked complex font

EUROPEAN_FONT 9 Stroked European font

BOLD_FONT 10 Stroked bold font

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Graphics Functions

DISPLAYING TEXT

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void settextjustify (int horiz, int vert);

Description    Name Value    Action

horiz    LEFT_TEXT 0 left-justify text

CENTER_TEXT 1 center text

RIGHT_TEXT 2 right-justify text

vertical    BOTTOM_TEXT 0 bottom-justify text

CENTER_TEXT 1 center text

TOP_TEXT 2 top-justify text

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Text Height, Text Widthint textheight (char *textstring); int textwidth (char *textstring);

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Use textheight to compute the height of strings, instead of doing the computations manually. By using this function, no source code modifications have to be made when different fonts are selected

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Mouse Routinesint mousecurrentx();int mousecurrenty();

int whichmousebutton(); LEFT_BUTTONRIGHT_BUTTON

bool mouseup();bool mousedown();void clearmouse();

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Introducing Delayvoid delay (int millisec);

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the length of time to sleep in milliseconds.

delay(50);Sleep(100);

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Setting the Colorvoid setcolor (int color);

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• Sets the text, line, circle, rectangle, ellipse, arc colors• Affects outline color of all filled shapes

setcolor(RED);setcolor(50);

//From 0 to 64

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Line Stylevoid setlinestyle (int linestyle, unsigned upattern, int thickness);

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Name Value    Description

SOLID_LINE 0 Solid line

DOTTED_LINE 1 Dotted line

CENTER_LINE 2 Centered line

DASHED_LINE 3 Dashed line

USERBIT_LINE    4 User-defined line style

thickness specifies whether the width of subsequent lines drawn will be normal or thick.

Name Value    Description

NORM_WIDTH 1 1 pixel wide

THICK_WIDTH    3 3 pixels wide

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Rectanglevoid rectangle (int left, int top, int right, int bottom);

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Fill Stylevoid setfillstyle (int pattern, int color);

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Pattern:

EMPTY_FILL, SOLID_FILL, LINE_FILL, LTSLASH_FILL, SLASH_FILL, BKSLASH_FILL,LTBKSLASH_FILL, HATCH_FILL, XHATCH_FILL, INTERLEAVE_FILL, WIDE_DOT_FILL, CLOSE_DOT_FILL, USER_FILL

• Affects filled-shapes

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barvoid bar (int left, int top, int right, int bottom);

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The upper left and lower right corners of the rectangle are given by (left, top) and (right, bottom), respectively. The coordinates refer to pixels.

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Bar3Dvoid bar3d (int left, int top, int right, int bottom, int depth, int topflag);

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bar3d draws a three-dimensional rectangular bar, then fills it using the current fill pattern and fill color. The three-dimensional outline of the bar is drawn in the current line style and color. The bar's depth in pixels is given by depth. The topflag parameter governs whether a three-dimensional top is put on the bar. If topflag is nonzero, a top is put on; otherwise, no top is put on the bar (making it possible to stack several bars on top of one another). The upper left and lower right corners of the rectangle are given by (left, top) and (right, bottom), respectively. To calculate a typical depth for bar3d, take 25% of the width of the bar, like this:

bar3d(left,top,right,bottom, (right-left)/4,1);

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Circlevoid circle (int x, int y, int radius);

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Ellipsevoid ellipse (int x, int y, int stangle, int endangle, int xradius, int yradius);

void fillellipse (int x, int y, int xradius, int yradius);

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ellipse draws an elliptical arc in the current drawing color with its center at (x,y) and the horizontal and vertical axes given by xradius and yradius, respectively. The ellipse travels from stangle to endangle. If stangle equals 0 and endangle equals 360, the call to ellipse draws a complete ellipse.

The angle for ellipse is reckoned counterclockwise, with 0 degrees at 3 o'clock, 90 degrees at 12 o'clock, and so on.

The linestyle parameter does not affect arcs, circles, ellipses, or pie slices. Only the thickness parameter is used.

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Putpixelvoid putpixel (int x, int y, int color);

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Arcvoid arc (int x, int y, int stangle, int endangle, int radius);

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Angles in degrees 0-360.0-right. Counter-clockwise (90-up, 180-left, 270-down)

The linestyle parameter does not affect arcs, circles, ellipses, or pie slices. Only the thickness parameter is used.

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Pieslicevoid pieslice (int x, int y, int stangle, int endangle, int radius);

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Use with setcolor() and setfillstyle() functions

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Fillpolyvoid fillpoly (int numpoints, int *polypoints);

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fillpoly draws the outline of a polygon with numpoints points in the current line style and color (just as drawpoly does), then fills the polygon using the current fill pattern and fill color. polypoints points to a sequence of (numpoints * 2) integers. Each pair of integers gives the x- and y-coordinates of a point on the polygon.

Array of integers

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Fillpoly Examplevoid fillpoly (int numpoints, int *polypoints);

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int poly[8]; int maxx, maxy;

maxx = getmaxx(); maxy = getmaxy(); poly[0] = 20; /* first vertex */ poly[1] = maxy / 2; poly[2] = maxx - 20; /* second vertex */ poly[3] = 20; poly[4] = maxx - 50; /* third vertex */ poly[5] = maxy - 20; poly[6] = maxx / 2; /* fourth, vertex */ poly[7] = maxy / 2; /* automatically closes the polygon */

fillpoly(4, poly); 4 points, 8 array elements

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Keyboard Handling

GetAsyncKeyState

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The GetAsyncKeyState function determines whether a key is up or down at the time the function is called, and whether the key was pressed after a previous call to GetAsyncKeyState.

To find other pre-defined constants: Using googlegoogle, type the following keywords: msdn vk_shift

Virtual-key code e.g.

vk_shiftvk_control

SHORT GetAsyncKeyState( int vKey ); // vKey - virtual-key code

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Keyboard Handling

GetAsyncKeyState

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void MoveSprite(){

if(GetAsyncKeyState(VK_UP) < 0) { SpriteY = SpriteY - 2; //up outtext("UP"); }

if(GetAsyncKeyState(VK_DOWN) < 0) { SpriteY = SpriteY + 2; //down outtext("DOWN"); ….

To find other pre-defined constants: Using google, type the following keywords: msdn virtual key codeshttp://msdn.microsoft.com/en-us/library/ms645540(VS.85).aspx

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Keyboard HandlingKeyboard HandlingMonitoring the Control and Shift keys:

if(GetAsyncKeyState(VK_CONTROL)<0) { ControlFlag =! ControlFlag; }

bool ControlFlag, ShiftFlag;

if(GetAsyncKeyState(VK_SHIFT)<0) { ShiftFlag =! ShiftFlag; }

For the Tank to Jump to the Right: Control + Shift + Right Arrow key

For the Tank to Jump to the Left: Control + Shift + Left Arrow key

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Keyboard HandlingKeyboard HandlingPossible approach in monitoring key combinations :

if(GetAsyncKeyState(VK_RIGHT)<0) {

XDir=RIGHT; if(ShiftFlag) {

outtext("SHIFT + RIGHT"); ShiftFlag=!ShiftFlag; } if(ControlFlag)

{ outtext("CTRL + RIGHT"); if (TankX < getmaxx()-W) TankX += 2; Angle=Angle-5; RaiseWheelFlag=TRUE; ControlFlag=!ControlFlag; }

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