Add ray_intersection_point Usage Example

public/usage-examples/physics/ray_intersection_point-1-example-oop.cs

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+using SplashKitSDK;
+
+namespace RayIntersectionPointExample
+{
+    public class Program
+    {
+        public static void Main()
+        {
+            // Open a window for the lantern scene
+            SplashKit.OpenWindow("The Raycast Lantern", 800, 600);
+
+            // Define obstacle rectangles (walls that block light)
+            Rectangle obstacle1 = SplashKit.RectangleFrom(150, 150, 100, 200);
+            Rectangle obstacle2 = SplashKit.RectangleFrom(500, 100, 150, 120);
+            Rectangle obstacle3 = SplashKit.RectangleFrom(350, 350, 200, 80);
+
+            // Define edges of each obstacle as lines for ray intersection
+            // Obstacle 1 edges
+            Line obs1Top = SplashKit.LineFrom(150, 150, 250, 150);
+            Line obs1Bottom = SplashKit.LineFrom(150, 350, 250, 350);
+            Line obs1Left = SplashKit.LineFrom(150, 150, 150, 350);
+            Line obs1Right = SplashKit.LineFrom(250, 150, 250, 350);
+
+            // Obstacle 2 edges
+            Line obs2Top = SplashKit.LineFrom(500, 100, 650, 100);
+            Line obs2Bottom = SplashKit.LineFrom(500, 220, 650, 220);
+            Line obs2Left = SplashKit.LineFrom(500, 100, 500, 220);
+            Line obs2Right = SplashKit.LineFrom(650, 100, 650, 220);
+
+            // Obstacle 3 edges
+            Line obs3Top = SplashKit.LineFrom(350, 350, 550, 350);
+            Line obs3Bottom = SplashKit.LineFrom(350, 430, 550, 430);
+            Line obs3Left = SplashKit.LineFrom(350, 350, 350, 430);
+            Line obs3Right = SplashKit.LineFrom(550, 350, 550, 430);
+
+            // Collect all edges into an array for easy iteration
+            const int numEdges = 12;
+            Line[] edges = {
+                obs1Top, obs1Bottom, obs1Left, obs1Right,
+                obs2Top, obs2Bottom, obs2Left, obs2Right,
+                obs3Top, obs3Bottom, obs3Left, obs3Right
+            };
+
+            // Number of rays to cast around the lantern
+            const int numRays = 360;
+
+            while (!SplashKit.QuitRequested())
+            {
+                SplashKit.ProcessEvents();
+
+                // Lantern follows the mouse position
+                Point2D lanternPos = SplashKit.MousePosition();
+
+                // Store the endpoint of each ray (intersection or window edge)
+                Point2D[] rayEndpoints = new Point2D[numRays];
+
+                // Cast rays in all directions from the lantern
+                for (int i = 0; i < numRays; i++)
+                {
+                    double angle = i * (360.0 / numRays);
+
+                    // Create a direction vector for this ray
+                    Vector2D heading = SplashKit.VectorFromAngle(angle, 1.0);
+
+                    // Start with a far-away default endpoint (edge of window)
+                    double closestDist = 1000.0;
+                    Point2D closestPt = SplashKit.PointAt(
+                        lanternPos.X + heading.X * closestDist,
+                        lanternPos.Y + heading.Y * closestDist
+                    );
+
+                    // Check each obstacle edge for intersection
+                    for (int j = 0; j < numEdges; j++)
+                    {
+                        Point2D hitPt = SplashKit.PointAt(0, 0);
+
+                        // Use ray_intersection_point to detect where the ray hits an edge
+                        if (SplashKit.RayIntersectionPoint(lanternPos, heading, edges[j], ref hitPt))
+                        {
+                            // Calculate distance to this intersection
+                            double dist = SplashKit.PointPointDistance(lanternPos, hitPt);
+
+                            // Keep the closest intersection point
+                            if (dist < closestDist)
+                            {
+                                closestDist = dist;
+                                closestPt = hitPt;
+                            }
+                        }
+                    }
+
+                    rayEndpoints[i] = closestPt;
+                }
+
+                // Render the scene
+                SplashKit.ClearScreen(Color.Black);
+
+                // Draw the illuminated area using filled triangles
+                // Each triangle connects the lantern to two adjacent ray endpoints
+                for (int i = 0; i < numRays; i++)
+                {
+                    int next = (i + 1) % numRays;
+
+                    // Fill triangle to create the lit region
+                    SplashKit.FillTriangle(
+                        SplashKit.RGBAColor(255, 220, 100, 40),
+                        lanternPos.X, lanternPos.Y,
+                        rayEndpoints[i].X, rayEndpoints[i].Y,
+                        rayEndpoints[next].X, rayEndpoints[next].Y
+                    );
+
+                    // Draw triangle outline for subtle light boundary
+                    SplashKit.DrawTriangle(
+                        SplashKit.RGBAColor(255, 220, 100, 15),
+                        lanternPos.X, lanternPos.Y,
+                        rayEndpoints[i].X, rayEndpoints[i].Y,
+                        rayEndpoints[next].X, rayEndpoints[next].Y
+                    );
+                }
+
+                // Draw light rays from lantern to intersection points
+                for (int i = 0; i < numRays; i += 6)
+                {
+                    SplashKit.DrawLine(SplashKit.RGBAColor(255, 200, 50, 20), lanternPos, rayEndpoints[i]);
+                }
+
+                // Draw the obstacle outlines on top
+                SplashKit.DrawRectangle(Color.DarkGray, obstacle1);
+                SplashKit.DrawRectangle(Color.DarkGray, obstacle2);
+                SplashKit.DrawRectangle(Color.DarkGray, obstacle3);
+
+                // Fill obstacles to make them look solid
+                SplashKit.FillRectangle(Color.Gray, obstacle1);
+                SplashKit.FillRectangle(Color.Gray, obstacle2);
+                SplashKit.FillRectangle(Color.Gray, obstacle3);
+
+                // Draw the lantern glow at the mouse position
+                SplashKit.FillCircle(Color.Yellow, lanternPos.X, lanternPos.Y, 8);
+                SplashKit.FillCircle(SplashKit.RGBAColor(255, 200, 50, 100), lanternPos.X, lanternPos.Y, 20);
+
+                // Display instructions
+                SplashKit.DrawText("Move the mouse to reposition the lantern", Color.White, 10, 10);
+                SplashKit.DrawText("Rays: " + numRays + " | Obstacles: 3", Color.White, 10, 30);
+
+                SplashKit.RefreshScreen(60);
+            }
+
+            SplashKit.CloseAllWindows();
+        }
+    }
+}

public/usage-examples/physics/ray_intersection_point-1-example-top-level.cs

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+using SplashKitSDK;
+using static SplashKitSDK.SplashKit;
+
+// Open a window for the lantern scene
+OpenWindow("The Raycast Lantern", 800, 600);
+
+// Define obstacle rectangles (walls that block light)
+Rectangle obstacle1 = RectangleFrom(150, 150, 100, 200);
+Rectangle obstacle2 = RectangleFrom(500, 100, 150, 120);
+Rectangle obstacle3 = RectangleFrom(350, 350, 200, 80);
+
+// Define edges of each obstacle as lines for ray intersection
+// Obstacle 1 edges
+Line obs1Top = LineFrom(150, 150, 250, 150);
+Line obs1Bottom = LineFrom(150, 350, 250, 350);
+Line obs1Left = LineFrom(150, 150, 150, 350);
+Line obs1Right = LineFrom(250, 150, 250, 350);
+
+// Obstacle 2 edges
+Line obs2Top = LineFrom(500, 100, 650, 100);
+Line obs2Bottom = LineFrom(500, 220, 650, 220);
+Line obs2Left = LineFrom(500, 100, 500, 220);
+Line obs2Right = LineFrom(650, 100, 650, 220);
+
+// Obstacle 3 edges
+Line obs3Top = LineFrom(350, 350, 550, 350);
+Line obs3Bottom = LineFrom(350, 430, 550, 430);
+Line obs3Left = LineFrom(350, 350, 350, 430);
+Line obs3Right = LineFrom(550, 350, 550, 430);
+
+// Collect all edges into an array for easy iteration
+const int numEdges = 12;
+Line[] edges = {
+    obs1Top, obs1Bottom, obs1Left, obs1Right,
+    obs2Top, obs2Bottom, obs2Left, obs2Right,
+    obs3Top, obs3Bottom, obs3Left, obs3Right
+};
+
+// Number of rays to cast around the lantern
+const int numRays = 360;
+
+while (!QuitRequested())
+{
+    ProcessEvents();
+
+    // Lantern follows the mouse position
+    Point2D lanternPos = MousePosition();
+
+    // Store the endpoint of each ray (intersection or window edge)
+    Point2D[] rayEndpoints = new Point2D[numRays];
+
+    // Cast rays in all directions from the lantern
+    for (int i = 0; i < numRays; i++)
+    {
+        double angle = i * (360.0 / numRays);
+
+        // Create a direction vector for this ray
+        Vector2D heading = VectorFromAngle(angle, 1.0);
+
+        // Start with a far-away default endpoint (edge of window)
+        double closestDist = 1000.0;
+        Point2D closestPt = PointAt(
+            lanternPos.X + heading.X * closestDist,
+            lanternPos.Y + heading.Y * closestDist
+        );
+
+        // Check each obstacle edge for intersection
+        for (int j = 0; j < numEdges; j++)
+        {
+            Point2D hitPt = PointAt(0, 0);
+
+            // Use ray_intersection_point to detect where the ray hits an edge
+            if (RayIntersectionPoint(lanternPos, heading, edges[j], ref hitPt))
+            {
+                // Calculate distance to this intersection
+                double dist = PointPointDistance(lanternPos, hitPt);
+
+                // Keep the closest intersection point
+                if (dist < closestDist)
+                {
+                    closestDist = dist;
+                    closestPt = hitPt;
+                }
+            }
+        }
+
+        rayEndpoints[i] = closestPt;
+    }
+
+    // Render the scene
+    ClearScreen(ColorBlack());
+
+    // Draw the illuminated area using filled triangles
+    // Each triangle connects the lantern to two adjacent ray endpoints
+    for (int i = 0; i < numRays; i++)
+    {
+        int next = (i + 1) % numRays;
+
+        // Fill triangle to create the lit region
+        FillTriangle(
+            RGBAColor(255, 220, 100, 40),
+            lanternPos.X, lanternPos.Y,
+            rayEndpoints[i].X, rayEndpoints[i].Y,
+            rayEndpoints[next].X, rayEndpoints[next].Y
+        );
+
+        // Draw triangle outline for subtle light boundary
+        DrawTriangle(
+            RGBAColor(255, 220, 100, 15),
+            lanternPos.X, lanternPos.Y,
+            rayEndpoints[i].X, rayEndpoints[i].Y,
+            rayEndpoints[next].X, rayEndpoints[next].Y
+        );
+    }
+
+    // Draw light rays from lantern to intersection points
+    for (int i = 0; i < numRays; i += 6)
+    {
+        DrawLine(RGBAColor(255, 200, 50, 20), lanternPos, rayEndpoints[i]);
+    }
+
+    // Draw the obstacle outlines on top
+    DrawRectangle(ColorDarkGray(), obstacle1);
+    DrawRectangle(ColorDarkGray(), obstacle2);
+    DrawRectangle(ColorDarkGray(), obstacle3);
+
+    // Fill obstacles to make them look solid
+    FillRectangle(ColorGray(), obstacle1);
+    FillRectangle(ColorGray(), obstacle2);
+    FillRectangle(ColorGray(), obstacle3);
+
+    // Draw the lantern glow at the mouse position
+    FillCircle(ColorYellow(), lanternPos.X, lanternPos.Y, 8);
+    FillCircle(RGBAColor(255, 200, 50, 100), lanternPos.X, lanternPos.Y, 20);
+
+    // Display instructions
+    DrawText("Move the mouse to reposition the lantern", ColorWhite(), 10, 10);
+    DrawText("Rays: " + numRays + " | Obstacles: 3", ColorWhite(), 10, 30);
+
+    RefreshScreen(60);
+}
+
+CloseAllWindows();