如何在MFC对话框中使用SDL2

方法/步骤

新建MFC应用程序，工程名称为MFCSDL

本例使用基于对话框的程序，注意勾选“基于对话框”

在MFCSDLDlg.h中添加SDL library 头文件和库文件应用，并定义所需变量。

#include "../SDL2-2.0.3/include/sdl.h"

#pragma comment(lib, "../SDL2-2.0.3/lib/x86/SDL2.lib")

#define WINDOW_W640

#define WINDOW_H480

#define NUM_SPRITES 100

#define MAX_SPEED 1

static SDL_Window* window

static SDL_Renderer *renderer

static SDL_Texture * sprite

static int window_w, window_h

static int sprite_w, sprite_h

static SDL_Rect *positions, *velocities

添加WM_KICKIDLE消息，该消息为微软保留消息，不公开，用它可以避免自己再重载实现消息循环。

具体过程如下:

1. 在 MFCSDLdlg.h文件加入

afx_msg LRESULT OnKickIdle(WPARAM wParam, LPARAM lParam)

2. 在MFCSDLDlg.cpp中加入消息映射

BEGIN_MESSAGE_MAP(CMFCSDLDlg, CDialogEx)

ON_WM_PAINT()

ON_WM_QUERYDRAGICON()

ON_MESSAGE(WM_KICKIDLE,OnKickIdle)

ON_WM_CLOSE()

END_MESSAGE_MAP()

3.添加OnKickIdle消息实现。

LRESULT CMFCSDLDlg::OnKickIdle(WPARAM wParam, LPARAM lParam)

{

SDL_Event event

int done = 0

while (!done)

{

/* Check for events */

while (SDL_PollEvent(&event)) {

switch (event.type) {

case SDL_WINDOWEVENT:

switch (event.window.event) {

case SDL_WINDOWEVENT_EXPOSED:

SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF)

SDL_RenderClear(renderer)

break

}

break

case SDL_QUIT:

done = 1

break

default:

break

}

}

MoveSprites(renderer, sprite)

}

return 0 //一定要返回0

}

在OnInitDialog函数中加入初始化代码。

BOOL CMFCSDLDlg::OnInitDialog()

{

CDialogEx::OnInitDialog()

// 设定此对话方块的图示。当应用程式的主视窗不是对话方块时，

// 框架会自动从事此作业

SetIcon(m_hIcon, TRUE) // 设定大图示

SetIcon(m_hIcon, FALSE) // 设定小图示

// TODO: 在此加入额外的初始设定

window = SDL_CreateWindowFrom(m_hWnd)

SDL_SetWindowTitle(window, "SDL Native Window Test")

renderer = SDL_CreateRenderer(window, -1, 0)

SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF)

SDL_RenderClear(renderer)

sprite = LoadSprite(renderer, "icon.bmp")

SDL_GetWindowSize(window, &window_w, &window_h)

SDL_QueryTexture(sprite, NULL, NULL, &sprite_w, &sprite_h)

positions = (SDL_Rect *) SDL_malloc(NUM_SPRITES * sizeof(SDL_Rect))

velocities = (SDL_Rect *) SDL_malloc(NUM_SPRITES * sizeof(SDL_Rect))

if (!positions || !velocities) {

SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Out of memory!\n")

// quit(2)

}

srand(time(NULL))

for (int i = 0i <NUM_SPRITES++i) {

positions[i].x = rand() % (window_w - sprite_w)

positions[i].y = rand() % (window_h - sprite_h)

positions[i].w = sprite_w

positions[i].h = sprite_h

velocities[i].x = 0

velocities[i].y = 0

while (!velocities[i].x &&!velocities[i].y) {

velocities[i].x = (rand() % (MAX_SPEED * 2 + 1)) - MAX_SPEED

velocities[i].y = (rand() % (MAX_SPEED * 2 + 1)) - MAX_SPEED

}

}

return TRUE // 传回 TRUE，除非您对控制项设定焦点

}

在MFCSDLDlg.cpp中，添加LoadSprite函数，注意是static 全局函数，放在所有函数最上方。其作用是加载一个图片精灵，本例使用一个笑脸图片。

static SDL_Texture *

LoadSprite(SDL_Renderer *renderer, char *file)

{

SDL_Surface *temp

SDL_Texture *sprite

/* Load the sprite image */

temp = SDL_LoadBMP(file)

if (temp == NULL) {

SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s", file, SDL_GetError())

return 0

}

/* Set transparent pixel as the pixel at (0,0) */

if (temp->format->palette) {

SDL_SetColorKey(temp, 1, *(Uint8 *) temp->pixels)

}

/* Create textures from the image */

sprite = SDL_CreateTextureFromSurface(renderer, temp)

if (!sprite) {

SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create texture: %s\n", SDL_GetError())

SDL_FreeSurface(temp)

return 0

}

SDL_FreeSurface(temp)

/* We're ready to roll. :) */

return sprite

}

在LoadSprite后添加MoveSprites函数，其作用是将精灵循环移动，实现动态效果。

static void

MoveSprites(SDL_Renderer * renderer, SDL_Texture * sprite)

{

if(renderer==NULL||sprite==NULL)

return

int sprite_w, sprite_h

int i

SDL_Rect viewport

SDL_Rect *position, *velocity

/* Query the sizes */

SDL_RenderGetViewport(renderer, &viewport)

SDL_QueryTexture(sprite, NULL, NULL, &sprite_w, &sprite_h)

/* Draw a gray background */

SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF)

SDL_RenderClear(renderer)

/* Move the sprite, bounce at the wall, and draw */

for (i = 0i <NUM_SPRITES++i) {

position = &positions[i]

velocity = &velocities[i]

position->x += velocity->x

if ((position->x <0) || (position->x >= (viewport.w - sprite_w))) {

velocity->x = -velocity->x

position->x += velocity->x

}

position->y += velocity->y

if ((position->y <0) || (position->y >= (viewport.h - sprite_h))) {

velocity->y = -velocity->y

position->y += velocity->y

}

/* Blit the sprite onto the screen */

SDL_RenderCopy(renderer, sprite, NULL, position)

}

/* Update the screen! */

SDL_RenderPresent(renderer)

}

8

以上完成，按F7编译，将icon.bmp文件拷贝到程序执行文件加下，运行程序，可看到如图效果。

第一种方式，静态连接：需要lib和dll文件。楼上的说的那个设置就是设置lib文件地址。如果不想在编译器里设置，可以进行代码里写： #pragma comment(lib, "my.lib")

第二种方式，直接动态加载dll，不需要lib文件，方法如下

typedef int (__cdecl *MYPROC)(LPWSTR)//这个定义根据你dll里的函数进行参数设置。参数要一至

MYPROC myfun

HMODULE h = LoadLibrary("my.dll")

myfun = (MYPROC)GetProcAddress(hinstLib, "myPuts")//写上dll里边那个函数名称

然后就可以直接调用 了。

最后FreeLibrary(h)

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