Add PBR Shader Example. (#229)

Examples/Shared/PbrLights.cs

@@ -0,0 +1,99 @@
+using static Raylib_cs.Raylib;
+using System.Numerics;
+
+namespace Examples.Shared;
+
+public struct PbrLight
+{
+    public PbrLightType Type;
+    public bool Enabled;
+    public Vector3 Position;
+    public Vector3 Target;
+    public Vector4 Color;
+    public float Intensity;
+
+    // Shader light parameters locations
+    public int TypeLoc;
+    public int EnabledLoc;
+    public int PositionLoc;
+    public int TargetLoc;
+    public int ColorLoc;
+    public int IntensityLoc;
+}
+
+public enum PbrLightType
+{
+    Directorional,
+    Point,
+    Spot
+}
+
+public class PbrLights
+{
+    public static PbrLight CreateLight(
+        int lightsCount,
+        PbrLightType type,
+        Vector3 pos,
+        Vector3 target,
+        Color color,
+        float intensity,
+        Shader shader
+    )
+    {
+        PbrLight light = new();
+
+        light.Enabled = true;
+        light.Type = type;
+        light.Position = pos;
+        light.Target = target;
+        light.Color = new Vector4(
+            color.R / 255.0f,
+            color.G / 255.0f,
+            color.B / 255.0f,
+            color.A / 255.0f
+        );
+        light.Intensity = intensity;
+
+        string enabledName = "lights[" + lightsCount + "].enabled";
+        string typeName = "lights[" + lightsCount + "].type";
+        string posName = "lights[" + lightsCount + "].position";
+        string targetName = "lights[" + lightsCount + "].target";
+        string colorName = "lights[" + lightsCount + "].color";
+        string intensityName = "lights[" + lightsCount + "].intensity";
+
+        light.EnabledLoc = GetShaderLocation(shader, enabledName);
+        light.TypeLoc = GetShaderLocation(shader, typeName);
+        light.PositionLoc = GetShaderLocation(shader, posName);
+        light.TargetLoc = GetShaderLocation(shader, targetName);
+        light.ColorLoc = GetShaderLocation(shader, colorName);
+        light.IntensityLoc = GetShaderLocation(shader, intensityName);
+
+        UpdateLightValues(shader, light);
+
+        return light;
+    }
+
+    public static void UpdateLightValues(Shader shader, PbrLight light)
+    {
+        // Send to shader light enabled state and type
+        Raylib.SetShaderValue(
+            shader,
+            light.EnabledLoc,
+            light.Enabled ? 1 : 0,
+            ShaderUniformDataType.Int
+        );
+        Raylib.SetShaderValue(shader, light.TypeLoc, (int)light.Type, ShaderUniformDataType.Int);
+
+        // Send to shader light target position values
+        Raylib.SetShaderValue(shader, light.PositionLoc, light.Position, ShaderUniformDataType.Vec3);
+
+        // Send to shader light target position values
+        Raylib.SetShaderValue(shader, light.TargetLoc, light.Target, ShaderUniformDataType.Vec3);
+
+        // Send to shader light color values
+        Raylib.SetShaderValue(shader, light.ColorLoc, light.Color, ShaderUniformDataType.Vec4);
+
+        // Send to shader light intensity values
+        Raylib.SetShaderValue(shader, light.IntensityLoc, light.Intensity, ShaderUniformDataType.Float);
+    }
+}