使用visualc++在桌面上绘制

draw on desktop using visual c++

本文关键字：绘制 桌面 visualc++ 使用      更新时间：2023-10-16

我正在编写一个opencv应用程序，使用visual studio vc++控制台应用程序绘制激光束。我想在桌面上画直线。我知道绘图功能在GDI32.dll中可用，但对如何将GDI32.dll与我的vc代码集成感到困惑。你能提出一些好的解决办法吗?

下面的代码在桌面上绘制一个蓝色矩形。

#include <iostream>
#include <Windows.h>
int main() {    
    /* hide console window */
    ShowWindow(FindWindowA("ConsoleWindowClass", NULL), false);
    /* Calling GetDC with argument 0 retrieves the desktop's DC */
    HDC hDC_Desktop = GetDC(0);
    /* Draw a simple blue rectangle on the desktop */
    RECT rect = { 20, 20, 200, 200 };
    HBRUSH blueBrush=CreateSolidBrush(RGB(0,0,255));
    FillRect(hDC_Desktop, &rect, blueBrush);
    Sleep(10);
    return 0;
}

只是为了好玩。直接在桌面上绘制的曼德布洛特分形。

#define MAGNITUDE_CUTOFF 100
#define NUMCOLOURS 256
#define WIDTH 640
#define HEIGHT 200
#define UP 72
#define DOWN 80
#define LEFT 75
#define RIGHT 77
#define SPACE 32
#define ENTER 13
#define ESCAPE 27
#define TAB 9
#define INSERT 82
#include <stdio.h>
#include <time.h>
#include <windows.h>
#include <iostream>
using namespace std;
int col(int x, int y);
void fract(void);
char op;
int ch,max_iterations;
double xmin = -2.10, xmax = 0.85, ymin = -1.5 , ymax = 1.5;
double  width_fact, height_fact;

int main(){
    COLORREF color = RGB(255,0,0); // COLORREF to hold the color info

    SetConsoleTitle("Pixel In Console!"); // Set text of the console so you can find the window
    HWND hwnd = FindWindow(NULL, "Pixel In Console?"); // Get the HWND
    HDC hdc = GetDC(hwnd); // Get the DC from that HWND
    width_fact = (xmax-xmin)/WIDTH;
    height_fact = (ymax-ymin)/HEIGHT;

    for( int x = 0 ; x < 640 ; x++ ){
        for (int y = 0;y < 480; y++ ){
         int blue = (col(x,y) & 0x0f) << 4;
         int green =    (col(x,y) & 0xf0) << 0;
         int red =  (col(x,y) & 0xf00) >> 4;
         SetPixel(hdc, x,y, RGB(red,green,blue));
        }
    }

    system("pause");
    ReleaseDC(hwnd, hdc); // Release the DC
    DeleteDC(hdc); // Delete the DC
    return(0);
}
void fract(){
   int x,y,icount=0;
   width_fact = (xmax-xmin)/WIDTH;
   height_fact = (ymax-ymin)/HEIGHT;
   for (y=0;y<HEIGHT;y++){
       for (x=0;x<WIDTH;x++){
          // setcolor(col(x,y));
          // gotoxy(x+3,y+3);printf("Û");
       }
   }
   //setcolor(15);
}

int col( int x, int y){
    int n,icount=0;
    float p,q,r,i,prev_r,prev_i;
    p= (( (float)x ) * width_fact) + (float)xmin;
    q= (( (float)y ) * height_fact) +(float)ymin;
    prev_i = 0;
    prev_r = 0;
    for (n=0; n <= NUMCOLOURS; n++){
        r = (prev_r * prev_r) - (prev_i * prev_i) +p;
        i = 2 * (prev_r * prev_i) +q;
        if (( r*r + i*i) < MAGNITUDE_CUTOFF ){
            prev_r = r;
            prev_i = i;
        }
        else {
            return n;
        }
    }
    return n;
}
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