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, 1 month ago

Goosey

122

March 05, 2004 07:45 PM

Thx for the help Greven. I found my error.. I had decided to use an enum instead of the const int''s for the list of TILECOLORs.. Well in the prototype I had accounted for this alteration, but I did not anywhere else in the code! Have it working perfectly now.

Thanks a lot for the help and for the great tutorial!

http://www.goosey.orgAIM: DarkGoosey ICQ: 14128911 MSN: DarkGoosey@hotmail.com Email: Goosey@gmail.com

122

March 06, 2004 10:31 AM

nice job! thanks man

Drevay

100

March 06, 2004 03:46 PM

Very cool, very impressive, and very nice of you to do such a thing.

Two thumbs up.

_________________Politics is the ability to foretell what is going to happen tomorrow, next week, next month and next year. And to have the ability afterwards to explain why it didn't happen. -- Winston ChurchillGDNet-0.2 - rate users the easy way with this nifty Firefox extension. Updated with new features.

CyberSlag5k

514

April 06, 2004 11:19 AM

Awsome. Definitely article worthy.

When you find yourself in the company of a halfling and an ill-tempered Dragon, remember, you do not have to outrun the Dragon...

Without order nothing can exist - without chaos nothing can evolve.

DigitalChaos

215

April 07, 2004 06:45 AM

I''m so glad this was re-stickied. It is awesome and a great tutorial!

Fishy1500

122

April 13, 2004 05:13 PM

Hi, i was able to get all the code to compile on VS.NET 2003 (i created a blank win32 project for this) but when I try to run it, nothing happens, no errors, nothing. Has anyone else had this problem???

Not sure what to do...

Evil_Greven

410

Author

April 13, 2004 08:59 PM

Did you create the bitmap file that it requires?

-Greven

Fishy1500

122

April 15, 2004 05:12 PM

I just copied the bitmap file from his tutorial

Evil_Greven

410

Author

April 15, 2004 07:22 PM

Well, I don''t have VS.NET but it sounds to me like the program is exiting immediately, if nothing is showing up at all.

This could be caused by a few things. Check your WinMain() function to see if it is correct, and also check TheWindowProc() function.

For instance, if in TheWindowProc() you happen to have:

//check for escape keyif(wParam=VK_ESCAPE)				{DestroyWindow(hWndMain);				return(0);//handled message	}

instead of:

//check for escape keyif(wParam==VK_ESCAPE)				{DestroyWindow(hWndMain);				return(0);//handled message	}

You won''t recieve any errors... and it will exit instantly and you''ll never even see the window created.

Check for something like that.

-Greven

ArtGeek

122

April 16, 2004 10:02 PM

Wow. If this is the basics of basic game programming, I'm screwed!

No, really. I kinda understand what's going on in the tutorial, but not enough to be confident in creating my own tetris clone without the help of the tutorial.

It isn't that the tut is bad, its just hard for me, personally, to learn from just looking at/typing up someone else's code. It doesn't click for me.

In order for me to learn well, I generally have to tinker. I've done some tinkering with the things I understand here (changing the size of the tiles and such) but I need some guidance as to how this code can be changed and what the changes would do.

I already have some ideas, like I'm guessing that if I changed the numbers [-][-] in the switch (newblock) statement I'd end up with some pretty funky looking block groupss! I also suppose that I could fairly easily ADD groups of blocks to the game so long as I make appropriate changes to the newblock=rand()%[number]; line.

Any other suggestions for tinkering that would help me understand the code better?

Thanks for the tutorial btw. I read that article that said the first step to learning to program was making a tetris clone, to which I responded 'Well, how do I do that?' Now I can find out... eventually.

[edited by - ArtGeek on April 16, 2004 11:06:12 PM]

[edited by - ArtGeek on April 16, 2004 11:41:18 PM]

----------------------RobynThis is probably some really stupid problem that can be fixed with the push of a button, but there''s a lot of buttons, and I don''t know which one to push.

Tetris clone in an hour with C++.

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