Tetris clone in an hour with C++.

Evil_Greven · 2012-04-06T04:15:39

I often see people asking "How to make tetris?" or "how should I start my first game?" Well, here's a short and sweet lesson on making a simple tetris clone. No fancy stuff this time, just the basics. This mini-tutorial is strictly for C++. I'll assume at least basic familiarization. You must create this project as a Win32 Application project. It includes only three files, main.cpp, bitmapobject.cpp, and bitmapobject.h. EDIT: MetaCipher converted the code to SDL format, which can be found on page 6. Go have a look! In main.cpp: //FALLING BLOCK GAME! //main.cpp //tell compiler to not include many unneeded header files. #define WIN32_LEAN_AND_MEAN //need this for windows stuff. #include <windows.h> //need this for srand and rand #include <stdlib.h> //now let's include our bitmapobject definitions #include "bitmapobject.h" That's all you need to start off. Next, let's include some handy-dandy defines that makes editing your program a thousand times easier. Seriously. //let's give our window a name #define WINDOWCLASS "FallingBlockGame" //let's give our window a title...er caption. #define WINDOWTITLE "A Falling Block Game!" That takes care of Windows. Now let's think ahead. What should we use if we're going to make a tetris clone? Hmm... well, seems to me map tiles would work perfectly! Let's make a size for each tile, then make a size for the map, PLUS an 8-block wide sidebar. //since we're using square blocks, let's only use a single size. const int TILESIZE=16; //now for the map... const int MAPWIDTH=10; const int MAPHEIGHT=30; const int GREY=8; Easy! Now, let's have some (you can use enumerations if you prefer) variables for the future bitmap. We need 9 colors, and 1 Do Not Draw, so 10 in all. const int TILENODRAW=-1; const int TILEBLACK=0; const int TILEGREY=1; const int TILEBLUE=2; const int TILERED=3; const int TILEGREEN=4; const int TILEYELLOW=5; const int TILEWHITE=6; const int TILESTEEL=7; const int TILEPURPLE=8; Alright, that's done. Let's do some function prototypes. We will need Game Init, Game Loop, Game Done, Draw Tile, Draw Map, New Block, Rotate Block, Collision Test, Move Block, Remove Row, and New Game. bool GameInit(); // game initialization function void GameLoop(); //where the game actually takes place void GameDone(); //clean up! void DrawTile(int x, int y, int tile); //coordinates & tile type void DrawMap(); //draw the whole map.. render function, basically void NewBlock(); //create a new block! void RotateBlock(); //rotate a block.. if you can! void Move(int x, int y); //coordinates to move. int CollisionTest(int nx, int ny); //test collision of blocks void RemoveRow(int row); //remove a row.. that would be the 'x'. void NewGame(); //make a new game! Pretty simple so far, eh? Now, let's throw in some global variables, bwahahahah! Global variables are preferred, because they are FAST. Speed is essential to a game. Thus, when you can, use them. But, be careful with them. The first two we need are an application handle and a main window handle. HINSTANCE hInstMain=NULL; //main app handle HWND hWndMain=NULL; //main window handle These are necessary for windows programming. Remember this, always. Next, let's create an array to hold the play area map's tile types. We will add one extra row for Map to make Y-movement collision detection easier. int Map[MAPWIDTH][MAPHEIGHT+1]; //the game map! Now, let's make a little structure for a game piece, then two variables of that structure; one for the actual piece, and one for the preview piece. struct Piece { int size[4][4]; int x; int y; }; Piece sPrePiece; //preview piece. Piece sPiece; //the 's' prefixes indicate this is a 'structure' Simple! Now, something we *REALLY* need is for timing. Let's call it start_time, of the DWORD type. We also need a GAMESTARTED boolean. DWORD start_time; //used in timing bool GAMESTARTED=false; //used by NewBlock() NOW, let's leave main.cpp briefly, and visit bitmapobject.h: //BitMapObject.h #ifndef BITMAPOBJECT_H #define BITMAPOBJECT_H #pragma once //we need this for windows stuff. #include <windows.h> Just the usual basics. We need to make a class for the bitmap object.. to store the bitmap, that is. We need a handle to a device context.. that is, an HDC, which refers to an output device, or multiple output devices. We also need a pair of HBITMAP; one old, and one new. We also need a width and height of the bitmap. class BitMapObject { private: //memory dc HDC hdcMemory; //new bitmap! HBITMAP hbmNewBitMap; //old bitmap. HBITMAP hbmOldBitMap; //width & height as integers. int iWidth; int iHeight; Now, let's add some functions. We need, of course, a constructor and destructor, a Load function, a Create function, a Destroy function, functions to return iHeight/iWidth, and a conversion to HDC (bwahah). Then we're done with the .h file. public: //constructor BitMapObject(); //destructor ~BitMapObject(); //loads bitmap from a file void Load(HDC hdcCompatible,LPCTSTR lpszFilename); //creates a blank bitmap void Create(HDC hdcCompatible, int width, int height); //destroys bitmap and dc void Destroy(); //return width int GetWidth(); //return height int GetHeight(); //converts to HDC operator HDC(); }; #endif Now, we're done with that. Let's go on and make the functions for the class in the bitmapobject.cpp file: //BitMapObject.cpp #include "bitmapobject.h" So we need the header file. Let's make the constructor, first, then the destructor. We need to set the values of the variables to 0/NULL (I prefer NULL on non-basic variables, and 0 on int/char/long/etc). BitMapObject::BitMapObject() { hdcMemory=NULL; hbmNewBitMap=NULL; hbmOldBitMap=NULL; iWidth=0; iHeight=0; } BitMapObject::~BitMapObject() { //if the hdcMemory hasn't been destroyed, do so if(hdcMemory) Destroy(); } Simple, yes? Now, let's load a bitmap! Fun! It really is easy. void BitMapObject::Load(HDC hdcCompatible, LPCTSTR lpszFilename) { //if hdcMemory isn't null, make it so captain! if(hdcMemory) Destroy(); //create memory dc. hdcMemory=CreateCompatibleDC(hdcCompatible); //load the bitmap hbmNewBitMap=(HBITMAP)LoadImage(NULL,lpszFilename,IMAGE_BITMAP,0,0,LR_LOADFROMFILE); //shove the image into the dc hbmOldBitMap=(HBITMAP)SelectObject(hdcMemory,hbmNewBitMap); //grab the bitmap's properties BITMAP bmp; GetObject(hbmNewBitMap,sizeof(BITMAP),(LPVOID)&bmp); //grab the width & height iWidth=bmp.bmWidth; iHeight=bmp.bmHeight; } Not hard. You might look up on MSDN for more info on the above functions, as they explain it better than I could :). Now, let's make that Create function! void BitMapObject::Create(HDC hdcCompatible, int width, int height) { //if hdcMemory isn't null, blow it up! if(hdcMemory) Destroy(); //create the memory dc. hdcMemory=CreateCompatibleDC(hdcCompatible); //create the bitmap hbmNewBitMap=CreateCompatibleBitmap(hdcCompatible, width, height); //shove the image into the dc hbmOldBitMap=(HBITMAP)SelectObject(hdcMemory, hbmNewBitMap); //change the width and height. iWidth=width; iHeight=height; } Not much new here. Now let's build that Destroy() function we've used so much! void BitMapObject::Destroy() { //restore old bitmap. SelectObject(hdcMemory, hbmOldBitMap); //delete new bitmap. DeleteObject(hbmNewBitMap); //delete device context. DeleteDC(hdcMemory); //set members to 0/NULL hdcMemory=NULL; hbmNewBitMap=NULL; hbmOldBitMap=NULL; iWidth=0; iHeight=0; } Pretty easy. Lastly to finish up the .cpp, let's do the HDC conversion, and the Height/Width functions. BitMapObject::operator HDC() { //return hdcMemory. return(hdcMemory); } int BitMapObject::GetWidth() { //return width return(iWidth); } int BitMapObject::GetHeight() { //return height return(iHeight); } Beautiful! We're finished with this file, now we can go back to main.cpp, where we left off.. in Global variables. Why did I leave off where I did? Because we need this class. Badly. We need to make a variable with this class to handle the Map, and one to handle the Blocks. //map for the program BitMapObject bmoMap; //block images BitMapObject bmoBlocks; That's that. Now, let's build a simple message handler. To make that more clear, Windows sends messages to the window all the bloody time. Some of those are useful to us, like a key being pressed or a mouse button being pressed. Most Windows applications have this function. DestroyWindow() beings the shutdown, and PostQuitMessage() tells the program it's exiting. The WM_PAINT might be confusing. It is called a LOT, and basically redraws the window. BitBlt() is the function we'll be using to draw our bitmaps. Yay Windows GDI! Don't have to bother with DirectX, and it still runs fairly well. LRESULT CALLBACK TheWindowProc(HWND hwnd,UINT uMsg,WPARAM wParam,LPARAM lParam) { //which message did we get? switch(uMsg) { case WM_KEYDOWN: { //check for escape key if(wParam==VK_ESCAPE) { DestroyWindow(hWndMain); return(0);//handled message } else if(wParam==VK_DOWN) //check for down arrow key { Move(0,1); return(0);//handled message } else if(wParam==VK_UP) //check for up arrow key { RotateBlock(); return(0);//handled message } else if(wParam==VK_LEFT) //check for left arrow key { Move(-1,0); return(0);//handled message } else if(wParam==VK_RIGHT) //check for right arrow key { Move(1,0); return(0);//handled message } }break; case WM_DESTROY://the window is being destroyed { //tell the application we are quitting PostQuitMessage(0); //handled message, so return 0 return(0); }break; case WM_PAINT://the window needs repainting { //a variable needed for painting information PAINTSTRUCT ps; //start painting HDC hdc=BeginPaint(hwnd,&ps); //redraw the map BitBlt(hdc,0,0,TILESIZE*MAPWIDTH+TILESIZE*GREY,TILESIZE*MAPHEIGHT,bmoMap,0,0,SRCCOPY); //end painting EndPaint(hwnd,&ps); //handled message, so return 0 return(0); }break; } //pass along any other message to default message handler return(DefWindowProc(hwnd,uMsg,wParam,lParam)); } Next, we come to the ever-formidable evil mountain that is known as WinMain(). This is where you make your window, and your pact with Bill Gates! Just smile and nod as you sign away your soul. But seriously, once you've made this window, you're going to use pretty much the same framework code for other games. Again, MSDN provides more uh, useful info on it. Yeah. int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nShowCmd) { //assign instance to global variable hInstMain=hInstance; //create window class WNDCLASSEX wcx; //set the size of the structure wcx.cbSize=sizeof(WNDCLASSEX); //class style wcx.style = CS_OWNDC | CS_HREDRAW | CS_VREDRAW | CS_DBLCLKS; //window procedure wcx.lpfnWndProc=TheWindowProc; //class extra wcx.cbClsExtra=0; //window extra wcx.cbWndExtra=0; //application handle wcx.hInstance=hInstMain; //icon wcx.hIcon=LoadIcon(NULL,IDI_APPLICATION); //cursor wcx.hCursor=LoadCursor(NULL,IDC_ARROW); //background color wcx.hbrBackground=(HBRUSH)GetStockObject(BLACK_BRUSH); //menu wcx.lpszMenuName=NULL; //class name wcx.lpszClassName=WINDOWCLASS; //small icon wcx.hIconSm=NULL; //register the window class, return 0 if not successful if(!RegisterClassEx(&wcx)) return(0); //create main window hWndMain=CreateWindowEx(0,WINDOWCLASS,WINDOWTITLE, WS_BORDER | WS_SYSMENU | WS_CAPTION| WS_VISIBLE,0,0,320,240,NULL,NULL,hInstMain,NULL); //error check if(!hWndMain) return(0); //if program initialization failed, then return with 0 if(!GameInit()) return(0); //message structure MSG msg; //message pump for( ; ; ) { //look for a message if(PeekMessage(&msg,NULL,0,0,PM_REMOVE)) { //there is a message //check that we arent quitting if(msg.message==WM_QUIT) break; //translate message TranslateMessage(&msg;; //dispatch message DispatchMessage(&msg;; } //run main game loop GameLoop(); } //clean up program data GameDone(); //return the wparam from the WM_QUIT message return(msg.wParam); } Now we get to the beginnings of the actual game! WHEE! First, Initialization is the key to victory. We use a temporar rectangle (RECT rcTemp) to clear out the window. Then, we create the map image, and similiarly clear it out. Lastly, we load the blocks bitmap file (which you will have to create on your own, more on that at the bottom of this mini-tutorial). Let's also put in the GameDone().. it has no code in it, since there's no need for it currently. Hey, you can use the framework for your own games :)! bool GameInit() { //set the client area size RECT rcTemp; SetRect(&rcTemp,0,0,MAPWIDTH*TILESIZE+TILESIZE*GREY,MAPHEIGHT*TILESIZE);//160x480 client area AdjustWindowRect(&rcTemp,WS_BORDER | WS_SYSMENU | WS_CAPTION| WS_VISIBLE,FALSE);//adjust the window size based on desired client area SetWindowPos(hWndMain,NULL,0,0,rcTemp.right-rcTemp.left,rcTemp.bottom-rcTemp.top,SWP_NOMOVE);//set the window width and height //create map image HDC hdc=GetDC(hWndMain); bmoMap.Create(hdc,MAPWIDTH*TILESIZE+TILESIZE*GREY,MAPHEIGHT*TILESIZE); FillRect(bmoMap,&rcTemp,(HBRUSH)GetStockObject(BLACK_BRUSH)); ReleaseDC(hWndMain,hdc); bmoBlocks.Load(NULL,"blocks.bmp"); NewGame(); return(true);//return success } void GameDone() { //clean up code goes here } Piece of cake. Actually, I'm having a cookie, but anyway, let's make the Game Loop. I bet you think this part will be hard? HAH! Well, we need to do timing, but that's about it. GetTickCount() runs in milliseconds, thus this locks the game to 1fps, and 1-second movement. You can change this in various ways, such as 1000 to 33 (for 30fps hard lock) and changing the automatic Move(0,1) on a timer (ex: if(timer==30) {timer=0; Move(0,1); } timer++;) void GameLoop() { if( (GetTickCount() - start_time) > 1000) { Move(0,1); start_time=GetTickCount(); } } See? SEE? I bet you didn't believe me, did you? Bah! Anyway, now to build the NewGame() function. We set up the start_time, and we initialize the Map array, then tell it to put in a new block & new void NewGame() { start_time=GetTickCount(); GAMESTARTED=false; //start out the map for(int x=0;x< MAPWIDTH;x++) { for(int y=0;y< MAPHEIGHT+1;y++) { if(y==MAPHEIGHT) //makes Y-collision easier. Map[x][y]=TILEGREY; else Map[x][y]=TILEBLACK; } } NewBlock(); DrawMap(); } Easy. Now, let's build the DrawTile() function. Simple enough, take a pair of coordinates and place the tile (block) of the specified type.. err color... er you get the picture. edit: I want to explain BitBlt() more. The first variable it needs is an a DESTINATION handle to the device context (remember the operator HDC() function? bmoMap returns that). The second two are starting X and Y coordinates, respectively, and the upper left corner of a window is 0,0, and the bottom right just depends on the size you have; in this case, 160,480. The next two determine how MUCH of the bitmap is sent to bmoMap, that is, they are the width and height respectively (since we have a square, we're using one size: TILESIZE). After that, it's another HDC, this time bmoBlocks, which is the SOURCE. Then, we have another pair of coordinates; these two determine where on the bitmap you are starting at... that is, if you wanted to be able to draw the whole bitmap, you'd use 0,0, but if you wanted to draw only the bottom right of the bitmap, you would use (for 16x16) 8,8. Lastly, you can use either SRCAND, SRCPAINT, or SRCCOPY, and these determine HOW the hmoBlocks are copied to hmoMap: SRCCOPY is a straight copy of the source that overwrites whatever's in the destination in that area, SRCAND copies the source to the destination using the AND operation (and we use it for bitmasking), while SRCPAINT copies the source to the destination using the XOR operation. void DrawTile(int x,int y,int tile)//put a tile { //mask first BitBlt(bmoMap,x*TILESIZE,y*TILESIZE,TILESIZE,TILESIZE,bmoBlocks,tile*TILESIZE,TILESIZE,SRCAND); //then image BitBlt(bmoMap,x*TILESIZE,y*TILESIZE,TILESIZE,TILESIZE,bmoBlocks,tile*TILESIZE,0,SRCPAINT); } Now we have a simple tile drawing function in place! Works great. First, it masks the spot with a background image (so you can do like, see-through numbers or whatever. It prints an image from bmoBlocks to bmoMap (which basically functions as a buffer). Now let's do our main rendering function; DrawMap()! Real easy, just draw the toolbar, then the preview block on top of that, then draw the background blocks and the moving piece that the player controls on that! void DrawMap()//draw screen { int xmy, ymx; //place the toolbar for(xmy=MAPWIDTH; xmy< MAPWIDTH+GREY; xmy++) for(ymx=0; ymx< MAPHEIGHT; ymx++) DrawTile(xmy, ymx, TILEGREY); //draw preview block for(xmy=0; xmy<4; xmy++) for(ymx=0; ymx<4; ymx++) if(sPrePiece.size[xmy][ymx] != TILENODRAW) DrawTile(sPrePiece.x+xmy, sPrePiece.y+ymx, sPrePiece.size[xmy][ymx]); //draw the map //loop through the positions for(xmy=0;xmy< MAPWIDTH;xmy++) for(ymx=0;ymx< MAPHEIGHT;ymx++) DrawTile(xmy,ymx,Map[xmy][ymx]); //draw moving block for(xmy=0; xmy<4; xmy++) for(ymx=0; ymx<4; ymx++) if(sPiece.size[xmy][ymx] != TILENODRAW) DrawTile(sPiece.x+xmy, sPiece.y+ymx, sPiece.size[xmy][ymx]); //invalidate the window rect InvalidateRect(hWndMain,NULL,FALSE); } We're doing good! Now, let's tackle the NewBlock() function. This is where we generate our little blocks. Let's assume the default shapes that Tetris(TM) fans are familiar with. We'll need to generate a preview piece, then replace the piece the player uses when s/he's finished with the current one. We'll also need to do a special case generation for the initial startup of the game. void NewBlock() { int newblock; int i,j; // 0 1 2 3 4 5 6 // X These // X XX X XX XX XX XX are // X XX XXX XX XX X X block // X X X types //begin game! make generate a block and then one in preview. srand(GetTickCount()); //initialize the piece to all blank. for(i=0; i<4; i++) for(j=0; j<4; j++) sPiece.size[ i ][j]=TILENODRAW; sPiece.x=MAPWIDTH/2-2; sPiece.y=-1; //let's see if the game's started yet if(GAMESTARTED == false) { //guess not.. //Generate a piece right off. //From now on, use previous preview block. GAMESTARTED=true; newblock=rand()%7; switch (newblock) { case 0: //Tower! { sPiece.size[1][0]=TILERED; sPiece.size[1][1]=TILERED; sPiece.size[1][2]=TILERED; sPiece.size[1][3]=TILERED; sPiece.y=0; }break; case 1: //Box! { sPiece.size[1][1]=TILEBLUE; sPiece.size[1][2]=TILEBLUE; sPiece.size[2][1]=TILEBLUE; sPiece.size[2][2]=TILEBLUE; }break; case 2: //Pyramid! { sPiece.size[1][1]=TILESTEEL; sPiece.size[0][2]=TILESTEEL; sPiece.size[1][2]=TILESTEEL; sPiece.size[2][2]=TILESTEEL; }break; case 3://Left Leaner { sPiece.size[0][1]=TILEYELLOW; sPiece.size[1][1]=TILEYELLOW; sPiece.size[1][2]=TILEYELLOW; sPiece.size[2][2]=TILEYELLOW; }break; case 4://Right Leaner { sPiece.size[2][1]=TILEGREEN; sPiece.size[1][1]=TILEGREEN; sPiece.size[1][2]=TILEGREEN; sPiece.size[0][2]=TILEGREEN; }break; case 5://Left Knight { sPiece.size[1][1]=TILEWHITE; sPiece.size[2][1]=TILEWHITE; sPiece.size[2][2]=TILEWHITE; sPiece.size[2][3]=TILEWHITE; }break; case 6://Right Knight { sPiece.size[2][1]=TILEPURPLE; sPiece.size[1][1]=TILEPURPLE; sPiece.size[1][2]=TILEPURPLE; sPiece.size[1][3]=TILEPURPLE; }break; } } else { for(i=0; i<4; i++) for(j=0; j<4; j++) sPiece.size[ i ][j]=sPrePiece.size[ i ][j]; } newblock=rand()%7; for(i=0; i<4; i++) for(j=0; j<4; j++) sPrePiece.size[ i ][j]=TILENODRAW; sPrePiece.x=MAPWIDTH+GREY/4; sPrePiece.y=GREY/4; switch (newblock) { case 0: //Tower! { sPrePiece.size[1][0]=TILERED; sPrePiece.size[1][1]=TILERED; sPrePiece.size[1][2]=TILERED; sPrePiece.size[1][3]=TILERED; }break; case 1: //Box! { sPrePiece.size[1][1]=TILEBLUE; sPrePiece.size[1][2]=TILEBLUE; sPrePiece.size[2][1]=TILEBLUE; sPrePiece.size[2][2]=TILEBLUE; }break; case 2: //Pyramid! { sPrePiece.size[1][1]=TILESTEEL; sPrePiece.size[0][2]=TILESTEEL; sPrePiece.size[1][2]=TILESTEEL; sPrePiece.size[2][2]=TILESTEEL; }break; case 3://Left Leaner { sPrePiece.size[0][1]=TILEYELLOW; sPrePiece.size[1][1]=TILEYELLOW; sPrePiece.size[1][2]=TILEYELLOW; sPrePiece.size[2][2]=TILEYELLOW; }break; case 4://Right Leaner { sPrePiece.size[2][1]=TILEGREEN; sPrePiece.size[1][1]=TILEGREEN; sPrePiece.size[1][2]=TILEGREEN; sPrePiece.size[0][2]=TILEGREEN; }break; case 5://Left Knight { sPrePiece.size[1][1]=TILEWHITE; sPrePiece.size[2][1]=TILEWHITE; sPrePiece.size[2][2]=TILEWHITE; sPrePiece.size[2][3]=TILEWHITE; }break; case 6://Right Knight { sPrePiece.size[2][1]=TILEPURPLE; sPrePiece.size[1][1]=TILEPURPLE; sPrePiece.size[1][2]=TILEPURPLE; sPrePiece.size[1][3]=TILEPURPLE; }break; } DrawMap(); } Ah, randomization. You could adjust these values to a more weighted approach, but these are straight, equal chance randomizations. Now, let's build our rotation function, RotateBlock(). Simple and easy: copy & rotate to a temporary, then check collisions, then copy it back to the original. Like switching two variables, sorta. void RotateBlock() { int i, j, temp[4][4]; //copy &rotate the piece to the temporary array for(i=0; i<4; i++) for(j=0; j<4; j++) temp[3-j][ i ]=sPiece.size[ i ][j]; //check collision of the temporary array with map borders for(i=0; i<4; i++) for(j=0; j<4; j++) if(temp[ i ][j] != TILENODRAW) if(sPiece.x + i < 0 || sPiece.x + i > MAPWIDTH - 1 || sPiece.y + j < 0 || sPiece.y + j > MAPHEIGHT - 1) return; //check collision of the temporary array with the blocks on the map for(int x=0; x< MAPWIDTH; x++) for(int y=0; y< MAPHEIGHT; y++) if(x >= sPiece.x && x < sPiece.x + 4) if(y >= sPiece.y && y < sPiece.y +4) if(Map[x][y] != TILEBLACK) if(temp[x - sPiece.x][y - sPiece.y] != TILENODRAW) return; //end collision check //successful! copy the rotated temporary array to the original piece for(i=0; i<4; i++) for(j=0; j<4; j++) sPiece.size[ i ][j]=temp[ i ][j]; DrawMap(); return; } And you thought game programming was hard. Well, it can be. Just not Tetris-clones. Now, let's build our Move() function. Check for a collision, then move, or put piece to map / remove row / start a new game if you're too high. void Move(int x, int y) { if(CollisionTest(x, y)) { if(y == 1) { if(sPiece.y<1) { //you lose! new game. NewGame(); } else { bool killblock=false; int i,j; //new block time! add this one to the list! for(i=0; i<4; i++) for(j=0; j<4; j++) if(sPiece.size[ i ][j] != TILENODRAW) Map[sPiece.x+i][sPiece.y+j] = sPiece.size[ i ][j]; //check for cleared row! for(j=0; j< MAPHEIGHT; j++) { bool filled=true; for(i=0; i< MAPWIDTH; i++) if(Map[ i ][j] == TILEBLACK) filled=false; if(filled) { RemoveRow(j); killblock=true; } } if(killblock) { for(i=0; i<4; i++) for(j=0; j<4; j++) sPiece.size[ i ][j]=TILENODRAW; } NewBlock(); } } } else { sPiece.x+=x; sPiece.y+=y; } DrawMap(); } Now, let's put in the CollisionTest() function. Really easy, just testing bounds and if it its another block. int CollisionTest(int nx, int ny) { int newx=sPiece.x+nx; int newy=sPiece.y+ny; int i,j,x,y; for(i=0; i< 4; i++) for(j=0; j< 4; j++) if(sPiece.size[ i ][j] != TILENODRAW) if(newx + i < 0 || newx + i > MAPWIDTH - 1 || newy + j < 0 || newy + j > MAPHEIGHT - 1) return 1; for(x=0; x< MAPWIDTH; x++) for(y=0; y< MAPHEIGHT; y++) if(x >= newx && x < newx + 4) if(y >= newy && y < newy +4) if(Map[x][y] != TILEBLACK) if(sPiece.size[x - newx][y - newy] != TILENODRAW) return 1; return 0; } Simple, yes? Now, the RemoveRow() function. Easy stuff here, just deleting a row and moving the rest down. void RemoveRow(int row) { int x,y; int counter=0; for(x=0; x< MAPWIDTH; x++) for(y=row; y>0; y--) Map[x][y]=Map[x][y-1]; } And that's it! You've got the code, now you just need the graphics. To make the graphics, create a new bitmap of a size TILESIZE*9 width, and TILESIZE*2 height. Now, divide this into 16x16 squares, or whatever TILESIZE you have, and you'll have two rows of 9 columns. Make the bottom row totally black (0 r,0 g,0 b). Make each column of the top row a different color. In order, make the columns Black, Grey, Blue, Red, Green, Yellow, White, Steel, and Purple. Black and Grey should be totally 1 color, while (for a good look!) the other colors should be in this format: x x x x x x x x x x x x x x x x x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m x o o o o o o o o o o o o o o m m m m m m m m m m m m m m m m m Where o = normal shade of a color, x = lighter shade of the color, and m = darker shade of the color. Enjoy. -Greven edit: annoying smilies. and the italic code. Gr. and the weird vanishing code. Double Gr. edit2: Re-added CollisionTest() function. Sorry about that. I had had it before, but somehow I had deleted it when trying to fix the vanishing code / italic code problems. My appologies. edit3: another annoying forum/code problem. added more detailed description of BitBlt() and timing edit4: changed the description of #define WIN32_LEAN_AND_MEAN, per correction from James Gregory edit5: Thanks for the SDL version, MetaCipher! [Edited by - Evil_Greven on July 13, 2004 12:13:46 AM]

For Beginners

Started by Evil_Greven November 22, 2003 12:56 AM

148 comments, last by jbadams 12 years ago

demonrealms

122

April 20, 2004 04:05 PM

got this: compiles fine but Bulding...that''s a difrfernt story:

------------------Configuration: tetris - Win32 Debug--------------------Linking...main.obj : error LNK2001: unresolved external symbol "public: __thiscall BitMapObject::~BitMapObject(void)" (??1BitMapObject@@QAE@XZ)main.obj : error LNK2001: unresolved external symbol "void __cdecl RotateBlock(void)" (?RotateBlock@@YAXXZ)main.obj : error LNK2001: unresolved external symbol "void __cdecl Move(int,int)" (?Move@@YAXHH@Z)main.obj : error LNK2001: unresolved external symbol "void __cdecl DrawMap(void)" (?DrawMap@@YAXXZ)main.obj : error LNK2001: unresolved external symbol "void __cdecl NewBlock(void)" (?NewBlock@@YAXXZ)Debug/tetris.exe : fatal error LNK1120: 5 unresolved externalsError executing link.exe.tetris.exe - 6 error(s), 0 warning(s)

Vigo

122

April 20, 2004 11:01 PM

Artgeek, I would suggest if you want to understand and tinker with the code, you need to get it into your memory more. Get a book on WinAPI as a reference and a book on DX just for some fun so ya don''t have to go through all that code with no result.. WinAPI is complicated and extremely hard to remember at times, but the key is repetition and taking a break with something fun..for instance DirectX, there are lots of stuffs you can tinker with. And with DirectX alot of it uses winapi as a backbone so you get the best of both worlds. Btw, whoever said the key to learning to program is to make a tetris clone..is an idiot.. The key to learning how to program is repetition, result, and fun.. heh btw nice game

Compiles great for me on dev-cpp. Duno about Linux tho, i''ll have to test that out on my debian box.
-Vigo.

GloveMan

122

April 28, 2004 10:10 AM

Good job however,
I am running visual c++ 6.0 and I am getting these errors, any ideas?? cuz I am all out of them.

--------------------Configuration: Tetris - Win32 Debug--------------------
Compiling...
main.cpp
F:\Projects\Tetris\main.cpp(144) : error C2601: ''WinMain'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(208) : error C2601: ''GameInit'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(225) : error C2601: ''GameDone'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(230) : error C2601: ''GameLoop'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(239) : error C2601: ''NewGame'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(260) : error C2601: ''DrawTile'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(269) : error C2601: ''DrawMap'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(298) : error C2601: ''NewBlock'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(447) : error C2601: ''RotateBlock'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(479) : error C2601: ''Move'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(532) : error C2601: ''CollisionTest'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(556) : error C2601: ''RemoveRow'' : local function definitions are illegal
F:\Projects\Tetris\main.cpp(567) : fatal error C1004: unexpected end of file found
Error executing cl.exe.

main.obj - 13 error(s), 0 warning(s)

GloveMan

122

April 28, 2004 10:24 AM

One more question, does the ''WinMain'' class replace the normal ''void main'' class when you are using windows.h? I am new to windows programming so I am just trying to figure this all out.

GloveMan

MetaCipher

145

April 28, 2004 01:27 PM

quote:Original post by GloveMan
One more question, does the ''WinMain'' class replace the normal ''void main'' class when you are using windows.h? I am new to windows programming so I am just trying to figure this all out.

GloveMan

Yes it does, and do keep in mind that the C++ standard now is to use ''int main''.

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GuerillaTactiks

April 06, 2011 03:23 AM

Maybe I just don't know enough C++ yet, but I think this was a terrible "lesson". I didn't even bother finishing because I had no idea what I was doing. I found myself copying what you had provided and trying to make sense of it myself since there was no explanation given.

jbadams

26,386

April 06, 2011 04:07 AM

You realise the last reply to this was [i]7 years ago[/i], and that the original post is from [i]2003[/i]?

I'm sure this topic was helpful to a lot of people, but you're right that it isn't the best learning resource available. You're unlikely to get any response or updates from the original poster at this point though. If you're interested in C++ game development and have spent some time learning the basics you could consider trying [url="http://lazyfoo.net/SDL_tutorials/index.php"]Lazy Foo's SDL tutorials[/url].

- Jason Astle-Adams

Mike Peck

100

April 06, 2012 03:09 AM

it may be an old post, but i think its just as valuable today as it was then, i just found it myself and wish ppl where still paying attention enough to answer questions, i have one or two

Mike Peck

100

April 06, 2012 03:25 AM

for example this one...i know im a noob but anyone know what this error is from?

Building Makefile: "C:\Dev-Cpp\projects\Makefile.win"
Executing make...
make.exe -f "C:\Dev-Cpp\projects\Makefile.win" all
g++.exe -c main.cpp -o main.o -I"C:/Dev-Cpp/lib/gcc/mingw32/3.4.2/include" -I"C:/Dev-Cpp/include/c++/3.4.2/backward" -I"C:/Dev-Cpp/include/c++/3.4.2/mingw32" -I"C:/Dev-Cpp/include/c++/3.4.2" -I"C:/Dev-Cpp/include"

g++.exe main.o bitmapobject.o -o "tetris.exe" -L"C:/Dev-Cpp/lib" -mwindows

C:/Dev-Cpp/lib/libmingw32.a(main.o)(.text+0x106):main.c: undefined reference to `WinMain@16'
collect2: ld returned 1 exit status

make.exe: *** [tetris.exe] Error 1

Execution terminated

jbadams

26,386

April 06, 2012 04:15 AM

Hehe, and that[i] last[/i] time I replied was around a year ago today. To be honest, you'd be better off simply starting a new topic; you could link to this one if you'd like to refer other people to it. The code in question is pretty old, and likely has a number of problems including incompatibility with more modern versions of the libraries used.

I'm going to close this topic -- but as mentioned, feel free to start a new one and link to this if you would like to.

I will however firstly point out [url="http://www.jasonbadams.net/20081218/why-you-shouldnt-use-dev-c/"]why you shouldn't use Dev-C++[/url], and also re-iterate what I said a year ago; while there is possibly still some value in this topic, as a beginner starting now you're probably better off with a more recently updated resource such as [url="http://lazyfoo.net/SDL_tutorials/index.php"]Lazy Foo's SDL tutorials[/url] (linked above). The original post of this topic is now 10 years old, and unfortunately that means that a lot of it simply isn't relevant any more, and the choice of Dev-C++ as a development environment will be nothing but harmful to your learning experience.

I hope that's helpful! [img]http://public.gamedev.net//public/style_emoticons/default/smile.png[/img]

- Jason Astle-Adams

Tetris clone in an hour with C++.

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