Learning Gama

Drawing shapes

Gama is an imediate mode library, what does that mean? simply that you draw the shapes directly, and you don't need to create shape objects or shape structs.

        #include <gama.h>

int main() {
  gm_init(500, 500, "Drawing shapes");

  do {
    gm_draw_rectangle(0, 0, 1, 1, GM_BLUE);
  } while(gm_yield());
}

      

you use gm_draw functions to draw to the canvas, when you do, the draw instruction is appended to a list of instructions which will finally be drawn when the app is ready, making your app more repsonsive since you don't have to wait for the app to be ready to start drawing.

# The coordinate system

To draw shapes you need obviously to indicate gama where to draw them, using specific coordinates, when you draw on gama you use a graph paper like coordinates where the x and y axae range from -1 to 1, but the x or y ranges may exceed that if your window is not completely square causing some parts to be hidden.

Thus a rectangle of width 2 occupies the whole square window.

# Reference

You can find other draw functions in the draw.h reference