SDL 基本使用

晕哥 · 2018-07-01 07:35:36

windows mingw 搭建SDL开发环境:
https://whycan.cn/t_687.html#p2375

官方例程:
https://wiki.libsdl.org/SDL_CreateWindow

// Example program:
// Using SDL2 to create an application window

#include "SDL.h"
#include <stdio.h>

int main(int argc, char* argv[]) {

    SDL_Window *window;                    // Declare a pointer

    SDL_Init(SDL_INIT_VIDEO);              // Initialize SDL2

    // Create an application window with the following settings:
    window = SDL_CreateWindow(
        "An SDL2 window",                  // window title
        SDL_WINDOWPOS_UNDEFINED,           // initial x position
        SDL_WINDOWPOS_UNDEFINED,           // initial y position
        640,                               // width, in pixels
        480,                               // height, in pixels
        SDL_WINDOW_OPENGL                  // flags - see below
    );

    // Check that the window was successfully created
    if (window == NULL) {
        // In the case that the window could not be made...
        printf("Could not create window: %s\n", SDL_GetError());
        return 1;
    }

    // The window is open: could enter program loop here (see SDL_PollEvent())

    SDL_Delay(3000);  // Pause execution for 3000 milliseconds, for example

    // Close and destroy the window
    SDL_DestroyWindow(window);

    // Clean up
    SDL_Quit();
    return 0;
}

运行结果:

晕哥 · 2018-07-01 07:39:10

http://lazyfoo.net/tutorials/SDL/index.php#Hello SDL

开始游戏编程v2.0
上次更新时间1/21/18

向大家致意，欢迎从头开始重新编码SDL开始的游戏编程。这次我们将使用已在SDL网站上发布的SDL 2进行编码。

这些教程是为希望从基于文本的游戏转移到带有图形的实时游戏的C ++程序员而设计的。通过这些教程的结尾，
您将了解制作您的第一个真正的视频游戏的基础知识！

晕哥 · 2018-07-01 07:49:10

http://lazyfoo.net/tutorials/SDL/02_getting_an_image_on_the_screen/index.php

/*This source code copyrighted by Lazy Foo' Productions (2004-2015)
and may not be redistributed without written permission.*/

//Using SDL and standard IO
#include <SDL2/SDL.h>
#include <stdio.h>

//Screen dimension constants
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;

//Starts up SDL and creates window
bool init();

//Loads media
bool loadMedia();

//Frees media and shuts down SDL
void close();

//The window we'll be rendering to
SDL_Window* gWindow = NULL;
	
//The surface contained by the window
SDL_Surface* gScreenSurface = NULL;

//The image we will load and show on the screen
SDL_Surface* gHelloWorld = NULL;

bool init()
{
	//Initialization flag
	bool success = true;

	//Initialize SDL
	if( SDL_Init( SDL_INIT_VIDEO ) < 0 )
	{
		printf( "SDL could not initialize! SDL_Error: %s\n", SDL_GetError() );
		success = false;
	}
	else
	{
		//Create window
		gWindow = SDL_CreateWindow( "SDL Tutorial", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN );
		if( gWindow == NULL )
		{
			printf( "Window could not be created! SDL_Error: %s\n", SDL_GetError() );
			success = false;
		}
		else
		{
			//Get window surface
			gScreenSurface = SDL_GetWindowSurface( gWindow );
		}
	}

	return success;
}

bool loadMedia()
{
	//Loading success flag
	bool success = true;

	//Load splash image
	gHelloWorld = SDL_LoadBMP( "02_getting_an_image_on_the_screen/hello_world.bmp" );
	if( gHelloWorld == NULL )
	{
		printf( "Unable to load image %s! SDL Error: %s\n", "02_getting_an_image_on_the_screen/hello_world.bmp", SDL_GetError() );
		success = false;
	}

	return success;
}

void close()
{
	//Deallocate surface
	SDL_FreeSurface( gHelloWorld );
	gHelloWorld = NULL;

	//Destroy window
	SDL_DestroyWindow( gWindow );
	gWindow = NULL;

	//Quit SDL subsystems
	SDL_Quit();
}

int main( int argc, char* args[] )
{
	//Start up SDL and create window
	if( !init() )
	{
		printf( "Failed to initialize!\n" );
	}
	else
	{
		//Load media
		if( !loadMedia() )
		{
			printf( "Failed to load media!\n" );
		}
		else
		{
			//Apply the image
			SDL_BlitSurface( gHelloWorld, NULL, gScreenSurface, NULL );
			
			//Update the surface
			SDL_UpdateWindowSurface( gWindow );

			//Wait two seconds
			SDL_Delay( 2000 );
		}
	}

	//Free resources and close SDL
	close();

	return 0;
}

晕哥 · 2018-07-01 08:07:18

http://lazyfoo.net/tutorials/SDL/03_event_driven_programming/index.php

事件驱动的编程

在之前的教程中，我们让程序在关闭之前等待几秒钟。在这个应用程序中，我们让应用程序等待，直到用户在关闭之前退出。

所以当用户没有退出时，我们会有应用程序循环。这个循环在应用程序处于活动状态时保持运行，称为主循环，有时称为主循环。
它是任何游戏应用程序的核心。

/*This source code copyrighted by Lazy Foo' Productions (2004-2015)
and may not be redistributed without written permission.*/

//Using SDL and standard IO
#include <SDL2/SDL.h>
#include <stdio.h>

//Screen dimension constants
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;

//Starts up SDL and creates window
bool init();

//Loads media
bool loadMedia();

//Frees media and shuts down SDL
void close();

//The window we'll be rendering to
SDL_Window* gWindow = NULL;
	
//The surface contained by the window
SDL_Surface* gScreenSurface = NULL;

//The image we will load and show on the screen
SDL_Surface* gXOut = NULL;

bool init()
{
	//Initialization flag
	bool success = true;

	//Initialize SDL
	if( SDL_Init( SDL_INIT_VIDEO ) < 0 )
	{
		printf( "SDL could not initialize! SDL_Error: %s\n", SDL_GetError() );
		success = false;
	}
	else
	{
		//Create window
		gWindow = SDL_CreateWindow( "SDL Tutorial", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN );
		if( gWindow == NULL )
		{
			printf( "Window could not be created! SDL_Error: %s\n", SDL_GetError() );
			success = false;
		}
		else
		{
			//Get window surface
			gScreenSurface = SDL_GetWindowSurface( gWindow );
		}
	}

	return success;
}

bool loadMedia()
{
	//Loading success flag
	bool success = true;

	//Load splash image
	gXOut = SDL_LoadBMP( "03_event_driven_programming/x.bmp" );
	if( gXOut == NULL )
	{
		printf( "Unable to load image %s! SDL Error: %s\n", "03_event_driven_programming/x.bmp", SDL_GetError() );
		success = false;
	}

	return success;
}

void close()
{
	//Deallocate surface
	SDL_FreeSurface( gXOut );
	gXOut = NULL;

	//Destroy window
	SDL_DestroyWindow( gWindow );
	gWindow = NULL;

	//Quit SDL subsystems
	SDL_Quit();
}

int main( int argc, char* args[] )
{
	//Start up SDL and create window
	if( !init() )
	{
		printf( "Failed to initialize!\n" );
	}
	else
	{
		//Load media
		if( !loadMedia() )
		{
			printf( "Failed to load media!\n" );
		}
		else
		{			
			//Main loop flag
			bool quit = false;

			//Event handler
			SDL_Event e;

			//While application is running
			while( !quit )
			{
				//Handle events on queue
				while( SDL_PollEvent( &e ) != 0 )
				{
					//User requests quit
					if( e.type == SDL_QUIT )
					{
						quit = true;
					}
				}

				//Apply the image
				SDL_BlitSurface( gXOut, NULL, gScreenSurface, NULL );
			
				//Update the surface
				SDL_UpdateWindowSurface( gWindow );
			}
		}
	}

	//Free resources and close SDL
	close();

	return 0;
}

晕哥 · 2018-07-01 08:22:08

/*This source code copyrighted by Lazy Foo' Productions (2004-2015)
and may not be redistributed without written permission.*/

//Using SDL, standard IO, and strings
#include <SDL2/SDL.h>
#include <stdio.h>
#include <string>

//Screen dimension constants
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;

//Key press surfaces constants
enum KeyPressSurfaces
{
	KEY_PRESS_SURFACE_DEFAULT,
	KEY_PRESS_SURFACE_UP,
	KEY_PRESS_SURFACE_DOWN,
	KEY_PRESS_SURFACE_LEFT,
	KEY_PRESS_SURFACE_RIGHT,
	KEY_PRESS_SURFACE_TOTAL
};

//Starts up SDL and creates window
bool init();

//Loads media
bool loadMedia();

//Frees media and shuts down SDL
void close();

//Loads individual image
SDL_Surface* loadSurface( std::string path );

//The window we'll be rendering to
SDL_Window* gWindow = NULL;
	
//The surface contained by the window
SDL_Surface* gScreenSurface = NULL;

//The images that correspond to a keypress
SDL_Surface* gKeyPressSurfaces[ KEY_PRESS_SURFACE_TOTAL ];

//Current displayed image
SDL_Surface* gCurrentSurface = NULL;

bool init()
{
	//Initialization flag
	bool success = true;

	//Initialize SDL
	if( SDL_Init( SDL_INIT_VIDEO ) < 0 )
	{
		printf( "SDL could not initialize! SDL Error: %s\n", SDL_GetError() );
		success = false;
	}
	else
	{
		//Create window
		gWindow = SDL_CreateWindow( "SDL Tutorial", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN );
		if( gWindow == NULL )
		{
			printf( "Window could not be created! SDL Error: %s\n", SDL_GetError() );
			success = false;
		}
		else
		{
			//Get window surface
			gScreenSurface = SDL_GetWindowSurface( gWindow );
		}
	}

	return success;
}

bool loadMedia()
{
	//Loading success flag
	bool success = true;

	//Load default surface
	gKeyPressSurfaces[ KEY_PRESS_SURFACE_DEFAULT ] = loadSurface( "04_key_presses/press.bmp" );
	if( gKeyPressSurfaces[ KEY_PRESS_SURFACE_DEFAULT ] == NULL )
	{
		printf( "Failed to load default image!\n" );
		success = false;
	}

	//Load up surface
	gKeyPressSurfaces[ KEY_PRESS_SURFACE_UP ] = loadSurface( "04_key_presses/up.bmp" );
	if( gKeyPressSurfaces[ KEY_PRESS_SURFACE_UP ] == NULL )
	{
		printf( "Failed to load up image!\n" );
		success = false;
	}

	//Load down surface
	gKeyPressSurfaces[ KEY_PRESS_SURFACE_DOWN ] = loadSurface( "04_key_presses/down.bmp" );
	if( gKeyPressSurfaces[ KEY_PRESS_SURFACE_DOWN ] == NULL )
	{
		printf( "Failed to load down image!\n" );
		success = false;
	}

	//Load left surface
	gKeyPressSurfaces[ KEY_PRESS_SURFACE_LEFT ] = loadSurface( "04_key_presses/left.bmp" );
	if( gKeyPressSurfaces[ KEY_PRESS_SURFACE_LEFT ] == NULL )
	{
		printf( "Failed to load left image!\n" );
		success = false;
	}

	//Load right surface
	gKeyPressSurfaces[ KEY_PRESS_SURFACE_RIGHT ] = loadSurface( "04_key_presses/right.bmp" );
	if( gKeyPressSurfaces[ KEY_PRESS_SURFACE_RIGHT ] == NULL )
	{
		printf( "Failed to load right image!\n" );
		success = false;
	}

	return success;
}

void close()
{
	//Deallocate surfaces
	for( int i = 0; i < KEY_PRESS_SURFACE_TOTAL; ++i )
	{
		SDL_FreeSurface( gKeyPressSurfaces[ i ] );
		gKeyPressSurfaces[ i ] = NULL;
	}

	//Destroy window
	SDL_DestroyWindow( gWindow );
	gWindow = NULL;

	//Quit SDL subsystems
	SDL_Quit();
}

SDL_Surface* loadSurface( std::string path )
{
	//Load image at specified path
	SDL_Surface* loadedSurface = SDL_LoadBMP( path.c_str() );
	if( loadedSurface == NULL )
	{
		printf( "Unable to load image %s! SDL Error: %s\n", path.c_str(), SDL_GetError() );
	}

	return loadedSurface;
}


int main( int argc, char* args[] )
{
	//Start up SDL and create window
	if( !init() )
	{
		printf( "Failed to initialize!\n" );
	}
	else
	{
		//Load media
		if( !loadMedia() )
		{
			printf( "Failed to load media!\n" );
		}
		else
		{	
			//Main loop flag
			bool quit = false;

			//Event handler
			SDL_Event e;

			//Set default current surface
			gCurrentSurface = gKeyPressSurfaces[ KEY_PRESS_SURFACE_DEFAULT ];

			//While application is running
			while( !quit )
			{
				//Handle events on queue
				while( SDL_PollEvent( &e ) != 0 )
				{
					//User requests quit
					if( e.type == SDL_QUIT )
					{
						quit = true;
					}
					//User presses a key
					else if( e.type == SDL_KEYDOWN )
					{
						//Select surfaces based on key press
						switch( e.key.keysym.sym )
						{
							case SDLK_UP:
							gCurrentSurface = gKeyPressSurfaces[ KEY_PRESS_SURFACE_UP ];
							break;

							case SDLK_DOWN:
							gCurrentSurface = gKeyPressSurfaces[ KEY_PRESS_SURFACE_DOWN ];
							break;

							case SDLK_LEFT:
							gCurrentSurface = gKeyPressSurfaces[ KEY_PRESS_SURFACE_LEFT ];
							break;

							case SDLK_RIGHT:
							gCurrentSurface = gKeyPressSurfaces[ KEY_PRESS_SURFACE_RIGHT ];
							break;

							default:
							gCurrentSurface = gKeyPressSurfaces[ KEY_PRESS_SURFACE_DEFAULT ];
							break;
						}
					}
				}

				//Apply the current image
				SDL_BlitSurface( gCurrentSurface, NULL, gScreenSurface, NULL );
			
				//Update the surface
				SDL_UpdateWindowSurface( gWindow );
			}
		}
	}

	//Free resources and close SDL
	close();

	return 0;
}

http://lazyfoo.net/tutorials/SDL/04_key_presses/index.php

这个demo演示响应 up/down/left/right 按键事件.

晕哥 · 2018-07-01 09:20:21

05

晕哥 · 2018-07-01 09:20:27

06

晕哥 · 2018-07-01 09:20:30

07

晕哥 · 2018-07-01 09:21:02

/*This source code copyrighted by Lazy Foo' Productions (2004-2015)
and may not be redistributed without written permission.*/

//Using SDL, SDL_image, standard IO, math, and strings
#include <SDL.h>
#include <SDL_image.h>
#include <stdio.h>
#include <string>
#include <cmath>

//Screen dimension constants
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 480;

//Starts up SDL and creates window
bool init();

//Loads media
bool loadMedia();

//Frees media and shuts down SDL
void close();

//Loads individual image as texture
SDL_Texture* loadTexture( std::string path );

//The window we'll be rendering to
SDL_Window* gWindow = NULL;

//The window renderer
SDL_Renderer* gRenderer = NULL;

bool init()
{
	//Initialization flag
	bool success = true;

	//Initialize SDL
	if( SDL_Init( SDL_INIT_VIDEO ) < 0 )
	{
		printf( "SDL could not initialize! SDL Error: %s\n", SDL_GetError() );
		success = false;
	}
	else
	{
		//Set texture filtering to linear
		if( !SDL_SetHint( SDL_HINT_RENDER_SCALE_QUALITY, "1" ) )
		{
			printf( "Warning: Linear texture filtering not enabled!" );
		}

		//Create window
		gWindow = SDL_CreateWindow( "SDL Tutorial", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN );
		if( gWindow == NULL )
		{
			printf( "Window could not be created! SDL Error: %s\n", SDL_GetError() );
			success = false;
		}
		else
		{
			//Create renderer for window
			gRenderer = SDL_CreateRenderer( gWindow, -1, SDL_RENDERER_ACCELERATED );
			if( gRenderer == NULL )
			{
				printf( "Renderer could not be created! SDL Error: %s\n", SDL_GetError() );
				success = false;
			}
			else
			{
				//Initialize renderer color
				SDL_SetRenderDrawColor( gRenderer, 0xFF, 0xFF, 0xFF, 0xFF );

				//Initialize PNG loading
				int imgFlags = IMG_INIT_PNG;
				if( !( IMG_Init( imgFlags ) & imgFlags ) )
				{
					printf( "SDL_image could not initialize! SDL_image Error: %s\n", IMG_GetError() );
					success = false;
				}
			}
		}
	}

	return success;
}

bool loadMedia()
{
	//Loading success flag
	bool success = true;

	//Nothing to load
	return success;
}

void close()
{
	//Destroy window	
	SDL_DestroyRenderer( gRenderer );
	SDL_DestroyWindow( gWindow );
	gWindow = NULL;
	gRenderer = NULL;

	//Quit SDL subsystems
	IMG_Quit();
	SDL_Quit();
}

SDL_Texture* loadTexture( std::string path )
{
	//The final texture
	SDL_Texture* newTexture = NULL;

	//Load image at specified path
	SDL_Surface* loadedSurface = IMG_Load( path.c_str() );
	if( loadedSurface == NULL )
	{
		printf( "Unable to load image %s! SDL_image Error: %s\n", path.c_str(), IMG_GetError() );
	}
	else
	{
		//Create texture from surface pixels
        newTexture = SDL_CreateTextureFromSurface( gRenderer, loadedSurface );
		if( newTexture == NULL )
		{
			printf( "Unable to create texture from %s! SDL Error: %s\n", path.c_str(), SDL_GetError() );
		}

		//Get rid of old loaded surface
		SDL_FreeSurface( loadedSurface );
	}

	return newTexture;
}

int main( int argc, char* args[] )
{
	//Start up SDL and create window
	if( !init() )
	{
		printf( "Failed to initialize!\n" );
	}
	else
	{
		//Load media
		if( !loadMedia() )
		{
			printf( "Failed to load media!\n" );
		}
		else
		{	
			//Main loop flag
			bool quit = false;

			//Event handler
			SDL_Event e;

			//While application is running
			while( !quit )
			{
				//Handle events on queue
				while( SDL_PollEvent( &e ) != 0 )
				{
					//User requests quit
					if( e.type == SDL_QUIT )
					{
						quit = true;
					}
				}

				//Clear screen
				SDL_SetRenderDrawColor( gRenderer, 0xFF, 0xFF, 0xFF, 0xFF );
				SDL_RenderClear( gRenderer );

				//Render red filled quad
				SDL_Rect fillRect = { SCREEN_WIDTH / 4, SCREEN_HEIGHT / 4, SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2 };
				SDL_SetRenderDrawColor( gRenderer, 0xFF, 0x00, 0x00, 0xFF );		
				SDL_RenderFillRect( gRenderer, &fillRect );

				//Render green outlined quad
				SDL_Rect outlineRect = { SCREEN_WIDTH / 6, SCREEN_HEIGHT / 6, SCREEN_WIDTH * 2 / 3, SCREEN_HEIGHT * 2 / 3 };
				SDL_SetRenderDrawColor( gRenderer, 0x00, 0xFF, 0x00, 0xFF );		
				SDL_RenderDrawRect( gRenderer, &outlineRect );
				
				//Draw blue horizontal line
				SDL_SetRenderDrawColor( gRenderer, 0x00, 0x00, 0xFF, 0xFF );		
				SDL_RenderDrawLine( gRenderer, 0, SCREEN_HEIGHT / 2, SCREEN_WIDTH, SCREEN_HEIGHT / 2 );

				//Draw vertical line of yellow dots
				SDL_SetRenderDrawColor( gRenderer, 0xFF, 0xFF, 0x00, 0xFF );
				for( int i = 0; i < SCREEN_HEIGHT; i += 4 )
				{
					SDL_RenderDrawPoint( gRenderer, SCREEN_WIDTH / 2, i );
				}

				//Update screen
				SDL_RenderPresent( gRenderer );
			}
		}
	}

	//Free resources and close SDL
	close();

	return 0;
}

http://lazyfoo.net/tutorials/SDL/08_geometry_rendering/index.php

晕哥 · 2018-07-02 21:56:48

终于把 ucgui 3.98 移植到 SDL 平台上了，感觉颜色有点不对劲, 得再改一改。

WhyCan Forum(哇酷开发者社区)

楼主 #1 2018-07-01 07:35:36 分享评论

SDL 基本使用

楼主 #2 2018-07-01 07:39:10 分享评论

Re: SDL 基本使用

楼主 #3 2018-07-01 07:49:10 分享评论

Re: SDL 基本使用

楼主 #4 2018-07-01 08:07:18 分享评论

Re: SDL 基本使用

楼主 #5 2018-07-01 08:22:08 分享评论

Re: SDL 基本使用

楼主 #6 2018-07-01 09:20:21 分享评论

Re: SDL 基本使用

楼主 #7 2018-07-01 09:20:27 分享评论

Re: SDL 基本使用

楼主 #8 2018-07-01 09:20:30 分享评论

Re: SDL 基本使用

楼主 #9 2018-07-01 09:21:02 分享评论

Re: SDL 基本使用

楼主 #10 2018-07-02 21:56:48 分享评论

Re: SDL 基本使用

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