determine point on line given a start/end points and percentage

[fluke 136]

basically i'll have a function which takes sx,sy, dx,dy and a value between 0 and 1, like so:

void drawLineSegment(int sx, int sy, int dx, int dy, float per);

you pass in the source and dest coord and it given the percentage, it will determine how much of the line to draw. for instance passing in a percentage of .5 will draw a line that starts at the source point and draws the line half-way to it's destination. the part i'm interested in isn't the line drawing code itself, but how to get that middle coordinate. most of my searching turns up point/line proximity, but this is obviously a little different, i think.

[DrEvil 1148]

draw(start,start + (end-start) * per);

[fluke 136]

it works PERFECT! thanks!