Functions_-_getangle.c

#include "raylib.h"
#include <math.h>

// Get our angle between two points.
static float getangle(float x1,float y1,float x2,float y2);

int main(void)
{
    // Initialization
    //--------------------------------------------------------------------------------------
    const int screenWidth = 800;
    const int screenHeight = 450;

    InitWindow(screenWidth, screenHeight, "raylib example.");
 
    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
    //--------------------------------------------------------------------------------------

    // Main game loop
    while (!WindowShouldClose())    // Detect window close button or ESC key
    {
        // Update
        //----------------------------------------------------------------------------------
        
        int x1 = GetMouseX();
        int y1 = GetMouseY();
        int x2 = screenWidth/2;
        int y2 = screenHeight/2;
        
        //----------------------------------------------------------------------------------
        // Draw
        //----------------------------------------------------------------------------------
        BeginDrawing();

            ClearBackground(RAYWHITE);
            
            DrawLine(x1,y1,x2,y2,RED);
            
            DrawText(FormatText("Angle between x1,y1,x2,y2 : %f",getangle(x1,y1,x2,y2)),0,0,20,DARKGRAY);

        EndDrawing();
        //----------------------------------------------------------------------------------
    }

    // De-Initialization
    //--------------------------------------------------------------------------------------
    CloseWindow();        // Close window and OpenGL context
    //--------------------------------------------------------------------------------------

    return 0;


}
// Return the angle from - to in float
float getangle(float x1,float y1,float x2,float y2){
    return (float)atan2(y2-y1, x2-x1);
}