SDL is Simple DirectMedia Layer.It is a cross-platform development library designed to provide low level access to audio, keyboard, mouse, joystick, and graphics hardware via OpenGL and Direct3D.It can be used to make animations and video games.
- It basically provides a set of APIs to interact with various devices like graphics hardware, audio, keyboard, mouse, etc.
- It is written in C programming language and works with C++ and various other languages like c# and python.
Installation on Linux ( For OS which uses the apt package manager eg : Ubuntu ):
- Run command sudo apt-get update on your terminal.
- Run command sudo apt-get install clang on your terminal.
- Run command sudo apt-get install libsdl2-2.0-0 libsdl2-dbg libsdl2-dev libsdl2-image-2.0-0 libsdl2-image-dbg libsdl2-image-dev on your terminal.
- We need to make a Makefile.So open a text editor of your choice and start writing the code below.
# A simple Makefile for compiling small SDL projects
# set the compiler
CC := clang
# set the compiler flags
CFLAGS := `sdl2-config --libs --cflags` -ggdb3 -O0 --std=c99 -Wall -lSDL2_image -lm
# add header files here
HDRS :=
# add source files here
SRCS := #file-name.c
# generate names of object files
OBJS := $(SRCS:.c=.o)
# name of executable
EXEC := #name your executable file
# default recipe
all: $(EXEC)
showfont: showfont.c Makefile
$(CC) -o $@ $@.c $(CFLAGS) $(LIBS)
glfont: glfont.c Makefile
$(CC) -o $@ $@.c $(CFLAGS) $(LIBS)
# recipe for building the final executable
$(EXEC): $(OBJS) $(HDRS) Makefile
$(CC) -o $@ $(OBJS) $(CFLAGS)
# recipe for building object files
#$(OBJS): $(@:.o=.c) $(HDRS) Makefile
# $(CC) -o $@ $(@:.o=.c) -c $(CFLAGS)
# recipe to clean the workspace
clean:
rm -f $(EXEC) $(OBJS)
.PHONY: all cleanHeader Files:
C++
// for initializing and shutdown functions#include <SDL2/SDL.h>// for rendering images and graphics on screen#include <SDL2/SDL_image.h>// for using SDL_Delay() functions#include <SDL2/SDL_timer.h> |
Initialization:
C++
#include <SDL2/SDL.h>#include <SDL2/SDL_image.h>#include <SDL2/SDL_timer.h>int main(int argc, char *argv[])
{ // returns zero on success else non-zero
if (SDL_Init(SDL_INIT_EVERYTHING) != 0) {
printf("error initializing SDL: %s\n", SDL_GetError());
}
SDL_Window* win = SDL_CreateWindow("GAME",
SDL_WINDOWPOS_CENTERED,
SDL_WINDOWPOS_CENTERED,
1000, 1000, 0);
while (1)
;
return 0;
} |
That will create a empty window on your screen.
Output:
We will write a simple program to explain rendering and I/O handling:
C++
#include <SDL2/SDL.h>#include <SDL2/SDL_image.h>#include <SDL2/SDL_timer.h>int main(int argc, char *argv[])
{ // returns zero on success else non-zero
if (SDL_Init(SDL_INIT_EVERYTHING) != 0) {
printf("error initializing SDL: %s\n", SDL_GetError());
}
SDL_Window* win = SDL_CreateWindow("GAME", // creates a window
SDL_WINDOWPOS_CENTERED,
SDL_WINDOWPOS_CENTERED,
1000, 1000, 0);
// triggers the program that controls
// your graphics hardware and sets flags
Uint32 render_flags = SDL_RENDERER_ACCELERATED;
// creates a renderer to render our images
SDL_Renderer* rend = SDL_CreateRenderer(win, -1, render_flags);
// creates a surface to load an image into the main memory
SDL_Surface* surface;
// please provide a path for your image
surface = IMG_Load("path");
// loads image to our graphics hardware memory.
SDL_Texture* tex = SDL_CreateTextureFromSurface(rend, surface);
// clears main-memory
SDL_FreeSurface(surface);
// let us control our image position
// so that we can move it with our keyboard.
SDL_Rect dest;
// connects our texture with dest to control position
SDL_QueryTexture(tex, NULL, NULL, &dest.w, &dest.h);
// adjust height and width of our image box.
dest.w /= 6;
dest.h /= 6;
// sets initial x-position of object
dest.x = (1000 - dest.w) / 2;
// sets initial y-position of object
dest.y = (1000 - dest.h) / 2;
// controls animation loop
int close = 0;
// speed of box
int speed = 300;
// animation loop
while (!close) {
SDL_Event event;
// Events management
while (SDL_PollEvent(&event)) {
switch (event.type) {
case SDL_QUIT:
// handling of close button
close = 1;
break;
case SDL_KEYDOWN:
// keyboard API for key pressed
switch (event.key.keysym.scancode) {
case SDL_SCANCODE_W:
case SDL_SCANCODE_UP:
dest.y -= speed / 30;
break;
case SDL_SCANCODE_A:
case SDL_SCANCODE_LEFT:
dest.x -= speed / 30;
break;
case SDL_SCANCODE_S:
case SDL_SCANCODE_DOWN:
dest.y += speed / 30;
break;
case SDL_SCANCODE_D:
case SDL_SCANCODE_RIGHT:
dest.x += speed / 30;
break;
default:
break;
}
}
}
// right boundary
if (dest.x + dest.w > 1000)
dest.x = 1000 - dest.w;
// left boundary
if (dest.x < 0)
dest.x = 0;
// bottom boundary
if (dest.y + dest.h > 1000)
dest.y = 1000 - dest.h;
// upper boundary
if (dest.y < 0)
dest.y = 0;
// clears the screen
SDL_RenderClear(rend);
SDL_RenderCopy(rend, tex, NULL, &dest);
// triggers the double buffers
// for multiple rendering
SDL_RenderPresent(rend);
// calculates to 60 fps
SDL_Delay(1000 / 60);
}
// destroy texture
SDL_DestroyTexture(tex);
// destroy renderer
SDL_DestroyRenderer(rend);
// destroy window
SDL_DestroyWindow(win);
// close SDL
SDL_Quit();
return 0;
} |
That will render a image on the window which can be controlled via your keyboard up, down, left, right.
Output:
References: https://www.libsdl.org/, https://github.com/vivek9236/rocket_game
Article Tags :
Recommended Articles