C Drawing Lines & Curves
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Drawing Straight Lines
line() draws a straight segment directly between two coordinates you specify explicitly — a start point (X1, Y1) and an end point (X2, Y2) — making it the simplest way to connect two known points on screen without tracking any drawing state.
Example: Drawing Straight Lines
#include <graphics.h>
int main() {
initgraph(0, 0, "");
line(50, 50, 200, 200);
getch();
closegraph();
return 0;
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Drawing from Current Position
BGI graphics maintains an implicit 'current position' cursor: moveto() repositions that cursor without drawing anything, while lineto() draws a line from wherever the cursor currently sits to a new target point and then leaves the cursor at that new point, which is convenient for drawing a connected chain of segments.
Example: Drawing from Current Position
#include <graphics.h>
int main() {
initgraph(0, 0, "");
moveto(50, 50);
lineto(150, 150);
getch();
closegraph();
return 0;
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Drawing Arcs
arc() draws a curved segment of a circle's circumference rather than a full circle, taking the center coordinates, a starting angle, an ending angle (both in degrees), and the radius — useful for things like pie-chart wedges or rounded corners.
Example: Drawing Arcs
#include <graphics.h>
int main() {
initgraph(0, 0, "");
arc(150, 150, 0, 180, 50);
getch();
closegraph();
return 0;
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Line Styles and Thickness
setlinestyle() changes how subsequently drawn lines look, accepting a style constant such as SOLID_LINE, DOTTED_LINE, or DASHED_LINE along with a thickness value, letting you visually distinguish different kinds of lines (like grid lines versus data lines) in the same drawing.
Example: Line Styles and Thickness
#include <graphics.h>
int main() {
initgraph(0, 0, "");
setlinestyle(DASHED_LINE, 0, 3);
line(50, 50, 200, 50);
getch();
closegraph();
return 0;
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Drawing Custom Curves
Plotting individual pixels at coordinates computed from a mathematical formula inside a loop — for example using sin() and cos() to generate points along a wave — lets you draw smooth curves that none of the built-in shape functions can produce directly.
Example: Drawing Custom Curves
#include <graphics.h>
#include <math.h>
int main() {
initgraph(0, 0, "");
for (int x = 0; x < 100; x++) {
int y = 100 + (int)(50 * sin(x * 0.1));
putpixel(x, y, WHITE);
}
getch();
closegraph();
return 0;
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