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c:graphics.h:mousey [2015/05/06 23:06] (current)
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 +===== mousey =====
 +
 +
 +====Syntax of mousey ==== 
 + <code c>
 +#include "graphics.h"
 +int mousey(void);
 +  </code>
 +
 +
 +==== Description of mousey ==== 
 +<code c>
 +The mousey function is available in the winbgim implementation of BGI
 +graphics. It returns the most recent y coordinate of the mouse within the
 +graphics window. Y-coordinates start with 0 at the top edge of the window
 +and increase to getmaxy( ) at the bottom edge of the window.
 +</code>
 +
 +
 +==== Example of mousey ====
 +<code c>
 +/* mouse example */
 +#include "graphics.h"
 +
 +// The click_handler will be called whenever the left mouse button is
 +// clicked. It checks copies the x,y coordinates of the click to
 +// see if the click was on a red pixel. If so, then the boolean
 +// variable red_clicked is set to true. Note that in general
 +// all handlers should be quick. If they need to do more than a little
 +// work, they should set a variable that will trigger the work going,
 +// and then return.
 +bool red_clicked = false;
 +void click_handler(int x, int y)
 +{
 +    if (getpixel(x,y) == RED)
 +  red_clicked = true;
 +}
 +
 +// Call this function to draw an isosoles triangle with the given base
 +and
 +// height. The triangle will be drawn just above the botton of the
 +screen.
 +void triangle(int base, int height)
 +{
 +    int maxx = getmaxx( );
 +    int maxy = getmaxy( );
 +
 +    line(maxx/2 - base/2, maxy - 10, maxx/2 + base/2, maxy - 10);
 +    line(maxx/2 - base/2, maxy - 10, maxx/2, maxy - 10 - height);
 +    line(maxx/2 + base/2, maxy - 10, maxx/2, maxy - 10 - height);
 +}
 +
 +void main(void)
 +{
 +    int maxx, maxy;  // Maximum x and y pixel coordinates
 +    int divisor;     // Divisor for the length of a triangle side
 +
 +    // Put the machine into graphics mode and get the maximum
 +coordinates:
 +    initwindow(450, 300);
 +    maxx = getmaxx( );
 +    maxy = getmaxy( );
 +
 +    // Register the function that handles a left mouse click
 +    registermousehandler(WM_LBUTTONDOWN, click_handler);
 +
 +    // Draw a white circle with red inside and a radius of 50 pixels:
 +    setfillstyle(SOLID_FILL, RED);
 +    setcolor(WHITE);
 +    fillellipse(maxx/2, maxy/2, 50, 50);
 +
 +    // Print a message and wait for a red pixel to be double clicked:
 +    settextstyle(DEFAULT_FONT, HORIZ_DIR, 2);
 +    outtextxy(20, 20, "Left click in RED to end.");
 +    setcolor(BLUE);
 +    red_clicked = false;
 +    divisor = 2;
 +    while (!red_clicked)
 +    {
 +  triangle(maxx/divisor, maxy/divisor);
 +  delay(500);
 +  divisor++;
 +    }
 +
 +    cout << "The mouse was clicked at: ";
 +    cout << "x=" << mousex( );
 +    cout << " y=" << mousey( ) << endl;
 +
 +    // Switch back to text mode:
 +    closegraph( );
 +}
 +</code>
 +
 +
 +==== See also ====
 +[[getmaxy]]
 +[[mousey]]
 +[[registermousehandler]]
 +
 +
 +===== output of mousey example ===== 
 +
 +    no output of example at the moment
 +    do not hesitate and add it...  
 +
 +
  
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c/graphics.h/mousey.txt · Last modified: 2015/05/06 23:06 (external edit)

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