MrTheFoxx

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About MrTheFoxx

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  1. FPS Limiting

    Right now, I have a loop for the game. I'll post some pseudo code to illustrate it. while(playing) { frames++; if(frames>FPS) frames=0; if(frames==FPS) { // All game functions for displaying the player and map and stuff. } } Am I going about this the right way? It has really slowed the game down, but there is still a lot of CPU being used. How can I cut down on that the right way? Is this a good way to limit the FPS? Thank you. :3
  2. Frame Independent Motion/Animation in SDL

    Thanks! So I can set up some if statements and if the time elapsed is equal to or beyond a certain value, change the animation frame for the player and/or the position? Good. Thanks!
  3. Frame Independent Motion/Animation in SDL

    I found something about that while I was Googling, but it has to do with C++. The timer class likely isn't present in C itself because C++ is C with Classes. There has to be some other alternative in C to what is available in C++. Or maybe I could program my own time calculator and integrate that in there...
  4. I've done a lot of research to find nothing, so I'm posting here. Here goes nothing. I have two images: a red circle and a blue circle. I have some controls set up. I want the sprite to swap between the red circle and the blue circle every half second and I want it to move across the screen at the same speed of forty pixels per second, both independent from the frame rate. Can anyone give me a minimal example of this being done in C (not C++ or C#... C)? Thank you.
  5. Screen Cropping SDL

    Ahh! Thanks for clearing that up. It really helped out. This should be all that I need in order to get scrolling working and everything, so thank you very much! Selecting the green arrow next to "Was this post useful to you?" increases your Reputation, right? I'll be doing that now on all of your posts here. Thanks again!
  6. Screen Cropping SDL

    Minimal Example: [CODE] #include <SDL/SDL.h> #include <SDL/SDL_image.h> int main() { SDL_Event kbrd; SDL_Surface *player, *screen, *background; player=IMG_Load("dot.png"); background=IMG_Load("white.png"); SDL_Rect playerpos; playerpos.x=-100; playerpos.y=-100; printf("Original Position: %d, %d\n",playerpos.x,playerpos.y); SDL_Init( SDL_INIT_EVERYTHING ); screen = SDL_SetVideoMode( 640, 480, 32, SDL_SWSURFACE ); unsigned char done=0, keydown=0, direction; while(!done) { while ( SDL_PollEvent(&kbrd) ) { switch (kbrd.type) { case SDL_KEYDOWN: #ifndef _WIN32_WCE if ( kbrd.key.keysym.sym == SDLK_ESCAPE ) { done = 1; } else if(kbrd.key.keysym.sym==SDLK_RIGHT) { direction=1; keydown=1; } else if(kbrd.key.keysym.sym==SDLK_LEFT) { direction=2; keydown=1; } else if(kbrd.key.keysym.sym==SDLK_UP) { direction=3; keydown=1; } else if(kbrd.key.keysym.sym==SDLK_DOWN) { direction=4; keydown=1; } #else done = 1; #endif break; case SDL_KEYUP: if(kbrd.key.keysym.sym==SDLK_RIGHT || kbrd.key.keysym.sym==SDLK_LEFT || kbrd.key.keysym.sym==SDLK_UP || kbrd.key.keysym.sym==SDLK_DOWN) keydown=0; break; case SDL_QUIT: done = 1; break; default: break; } } SDL_BlitSurface(background,NULL,screen,NULL); SDL_BlitSurface(player,NULL,screen,&playerpos); SDL_Flip(screen); if(keydown && direction==1) playerpos.x+=4; if(keydown && direction==2) playerpos.x-=4; if(keydown && direction==3) playerpos.y-=4; if(keydown && direction==4) playerpos.y+=4; if(keydown) printf("%d, %d\n",playerpos.x,playerpos.y); } return(0); } [/CODE] I used a 640x480 solid white image for white.png and a 16x16 red dot for dot.png. Substitute these with whatever you have readily available. The player (dot) will not go into negative coordinates no matter what. (Controls are Up, Down, Left, and Right on the keyboard.) I was hoping there would be a way to take the "world space co-ordinates" and crop out the "screen space co-ordinates" without having to shift objects around.
  7. Screen Cropping SDL

    So what you are saying is to go through and subtract the camera position from the position of each object on the map, from the player to the blocks that make up the stage itself? This is something that I have tried, but the objects that go under 0, 0 as their coordinates (-100, 0, for example) are rendered at the origin (upper-left-hand corner) of the screen. Perhaps adding [b]if(object[c].x-camera.x<0 || object[c].y-camera.y<0) display[c]=0; [/b](with display[c]=0; disabling displaying the tile) will make the object not be displayed if it has such coordinates? Did I read your response incorrectly, or are we on the same page? Move all of the objects in the map in order to have camera movement? And does the solution I posted work? Thank you for your time. I appreciate it. EDIT: The problem with the code I posted is that if an object goes beyond 0, 0, it isn't displayed. This is good, but part of the object would be cut off each time. Time for another diagram. [img]http://i1115.photobucket.com/albums/k545/MrTheFoxx/ScreensDiagramMovementBlock.png[/img] And because the block can't be drawn from before 0 so it is only halfway into or halfway out of the viewing area, that is not an option. How would I avoid such a problem? I know I could put a black border around the screen, but there has to be some other way to do this. Do you understand what I'm saying? Even if the X Coordinate of a block is -400, it is still displayed at 0 on the screen for its X Coordinate. Again, thanks. I apologize if I am not being easy to understand. EDIT #2: I made a program prints the X Coordinate of an object after setting that to -400 and it prints 0 instead. I'm going to conclude that object.x and object.y are unsigned integers and therefore can't be set equal to anything less than 0 and be expected to work. All of this is how I got lost in the first place when trying to figure out how to get a camera working. Please give me your insight. Thanks.
  8. Screen Cropping SDL

    This is one of the few things bugging me. Getting a camera to scroll. I load the whole area, but I need to crop out only a certain part of the screen and display it... like so: [quote] [img]http://i1115.photobucket.com/albums/k545/MrTheFoxx/Whole.png[/img] Becomes... [img]http://i1115.photobucket.com/albums/k545/MrTheFoxx/Part.png[/img] [/quote] (I used Quote tags so the white in the images doesn't blend with the post background.) I would change the offset to crop throughout the map as the player moved, which would equal camera scrolling. Can someone give me some example SDL code for doing this? I'm sure it is simple. I just don't understand it. I can already do it with an image and make scrolling backgrounds. It is just making the player and enemies and such move with the camera that is confusing. Please clear this up for me. Thank you. [img]http://public.gamedev.net//public/style_emoticons/default/smile.png[/img]
  9. SDL - Camera Movement

    Thanks for the input. However, this was what I was describing, the theorem you mentioned. The problem with it is that the upper-left-hand-corner of the screen itself stays locked at 0, 0. Anything that attempts to pass that boundary can't and is therefore locked at 0, 0 as well. So let's say the player was going screen right. Everything was moving screen left as to keep the whole thing in the viewing range and to show that the stage was moving. Whenever the stage parts collided with the left-most side of the screen, they didn't go beyond that and began cumulating at that part of the screen. Then, when the player decided to move screen left, they couldn't due to this same problem, and the stage wouldn't properly move to the right to show camera movement. All of the parts that met 0, 0 retained that value and were moving at the same rate. This is kind of difficult to explain. I will provide a set of diagrams if necessary. Instead, it would be better if the viewing range (0,0 to 640, 480) moved with the player and we saw different regions of the screen without having to go about subtracting or adding to the enemies, map tiles, and so on. How to do that was my initial question. It doesn't seem impossible.
  10. SDL - Camera Movement

    My progress was going well until I realized that I'm going to need some sort of camera movement in my levels. At first, I felt that I could just have each tile moved as the player moves and that would be camera movement from one part of the level to the next. Is there a more efficient way to do this, such as having the viewing area itself follow the player instead of leaving it in one place and moving each and every part of the area (including enemies and other things) based on player movement? Thank you! ^^