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Scrolling Text

Posted: Wed May 07, 2014 2:03 pm
by Embedder
Hello,
i installed and tested openvg library on my rasmberry pi board. Examples are a good starting point for learning but i still can't figure out how to make a text move-scroll. in fact i want to make a newsticker in the bottom of the screen.
Can anybody give me a starting point for that.
Thanks

Re: Scrolling Text

Posted: Wed May 07, 2014 5:43 pm
by Embedder
i found this method for scrolling a string horizontally:

void Scroll(char const *str)
{
while (*str++)
{
puts(stdin,getsInLen(), MAX_SCROLL_CHAR);
}
}

i will use openvg Text() function instead of puts.

Any thoughts ?

Re: Scrolling Text

Posted: Sun May 11, 2014 7:01 pm
by ajstarks

Code: Select all

// text crawl 
package main

import (
        "bufio"
        "github.com/ajstarks/openvg"
        "os"
        "time"
)

func main() {
        width, height := openvg.Init()

        x := openvg.VGfloat(width) * 0.10
        h2 := openvg.VGfloat(height / 2)
        w := openvg.VGfloat(width)
        fs := width/20
        s := "These are the times that try men's souls"
        openvg.Start(width, height)
        openvg.BackgroundColor("black")
        for i := 0; i < len(s); i++ {
                openvg.FillRGB(44, 100, 232, 1)
                openvg.Rect(0, h2/2, w, h2)
                openvg.FillColor("white")
                openvg.Text(x, h2, s[i:], "serif", fs)
                time.Sleep(150*time.Millisecond)
                openvg.End()
        }
        openvg.FillRGB(44, 100, 232, 1)
        openvg.Rect(0, h2/2, w, h2)
        openvg.End()

        bufio.NewReader(os.Stdin).ReadBytes('\n')
        openvg.Finish()
}

Re: Scrolling Text

Posted: Mon May 12, 2014 3:32 pm
by Embedder
Thanks i will try that !