Spot lights

main.go

@@ -26,9 +26,10 @@ import (
 /*
 @TODO:
 	- Rendering:
-		- Phong lighting model
-		- Point lights
-		- Spotlights
+		- Phong lighting model ✅
+		- Directional lights ✅
+		- Point lights ✅
+		- Spotlights ✅
 		- HDR
 		- Cascaded shadow mapping
 		- Skeletal animations
@@ -62,6 +63,7 @@ type PointLight struct {
 }
 
 type SpotLight struct {
+	Pos           gglm.Vec3
 	Dir           gglm.Vec3
 	DiffuseColor  gglm.Vec3
 	SpecularColor gglm.Vec3
@@ -69,6 +71,18 @@ type SpotLight struct {
 	OuterCutoff   float32
 }
 
+// SetCutoffs properly sets the cosine values of the cutoffs using the passed
+// degrees.
+//
+// The light has full intensity within the inner cutoff, falloff between
+// inner-outer cutoff, and zero light beyond the outer cutoff.
+//
+// The inner cuttoff degree must be *smaller* than the outer cutoff
+func (s *SpotLight) SetCutoffs(innerCutoffAngleDeg, outerCutoffAngleDeg float32) {
+	s.InnerCutoff = gglm.Cos32(innerCutoffAngleDeg * gglm.Deg2Rad)
+	s.OuterCutoff = gglm.Cos32(outerCutoffAngleDeg * gglm.Deg2Rad)
+}
+
 const (
 	camSpeed         = 15
 	mouseSensitivity = 0.5
@@ -148,6 +162,17 @@ var (
 			Quadratic:     0.032,
 		},
 	}
+	spotLights = [...]SpotLight{
+		{
+			Pos:           *gglm.NewVec3(0, 5, 0),
+			Dir:           *gglm.NewVec3(0, -1, 0),
+			DiffuseColor:  *gglm.NewVec3(0, 1, 1),
+			SpecularColor: *gglm.NewVec3(1, 1, 1),
+			// These must be cosine values
+			InnerCutoff: gglm.Cos32(15 * gglm.Deg2Rad),
+			OuterCutoff: gglm.Cos32(20 * gglm.Deg2Rad),
+		},
+	}
 )
 
 type Game struct {
@@ -456,6 +481,36 @@ func (g *Game) updateLights() {
 		containerMat.SetUnifFloat32(indexString+".quadratic", pl.Quadratic)
 		palleteMat.SetUnifFloat32(indexString+".quadratic", pl.Quadratic)
 	}
+
+	for i := 0; i < len(spotLights); i++ {
+
+		l := &spotLights[i]
+		indexString := "spotLights[" + strconv.Itoa(i) + "]"
+
+		whiteMat.SetUnifVec3(indexString+".pos", &l.Pos)
+		containerMat.SetUnifVec3(indexString+".pos", &l.Pos)
+		palleteMat.SetUnifVec3(indexString+".pos", &l.Pos)
+
+		whiteMat.SetUnifVec3(indexString+".dir", &l.Dir)
+		containerMat.SetUnifVec3(indexString+".dir", &l.Dir)
+		palleteMat.SetUnifVec3(indexString+".dir", &l.Dir)
+
+		whiteMat.SetUnifVec3(indexString+".diffuseColor", &l.DiffuseColor)
+		containerMat.SetUnifVec3(indexString+".diffuseColor", &l.DiffuseColor)
+		palleteMat.SetUnifVec3(indexString+".diffuseColor", &l.DiffuseColor)
+
+		whiteMat.SetUnifVec3(indexString+".specularColor", &l.SpecularColor)
+		containerMat.SetUnifVec3(indexString+".specularColor", &l.SpecularColor)
+		palleteMat.SetUnifVec3(indexString+".specularColor", &l.SpecularColor)
+
+		whiteMat.SetUnifFloat32(indexString+".innerCutoff", l.InnerCutoff)
+		containerMat.SetUnifFloat32(indexString+".innerCutoff", l.InnerCutoff)
+		palleteMat.SetUnifFloat32(indexString+".innerCutoff", l.InnerCutoff)
+
+		whiteMat.SetUnifFloat32(indexString+".outerCutoff", l.OuterCutoff)
+		containerMat.SetUnifFloat32(indexString+".outerCutoff", l.OuterCutoff)
+		palleteMat.SetUnifFloat32(indexString+".outerCutoff", l.OuterCutoff)
+	}
 }
 
 func (g *Game) Update() {
@@ -544,35 +599,91 @@ func (g *Game) showDebugWindow() {
 	imgui.Spacing()
 
 	// Point lights
-	imgui.Text("Point Lights")
-
-	if imgui.BeginListBoxV("", imgui.Vec2{Y: 200}) {
+	if imgui.BeginListBoxV("Point Lights", imgui.Vec2{Y: 200}) {
 
 		for i := 0; i < len(pointLights); i++ {
 
 			pl := &pointLights[i]
-			indexString := strconv.Itoa(i)
+			indexNumString := strconv.Itoa(i)
 
-			if !imgui.TreeNodeExStrV("Light "+indexString, imgui.TreeNodeFlagsSpanAvailWidth) {
+			if !imgui.TreeNodeExStrV("Point Light "+indexNumString, imgui.TreeNodeFlagsSpanAvailWidth) {
 				continue
 			}
 
+			indexString := "pointLights[" + indexNumString + "]"
+
 			if imgui.DragFloat3("Pos", &pl.Pos.Data) {
-				whiteMat.SetUnifVec3("pointLights["+indexString+"].pos", &pl.Pos)
-				containerMat.SetUnifVec3("pointLights["+indexString+"].pos", &pl.Pos)
-				palleteMat.SetUnifVec3("pointLights["+indexString+"].pos", &pl.Pos)
+				whiteMat.SetUnifVec3(indexString+".pos", &pl.Pos)
+				containerMat.SetUnifVec3(indexString+".pos", &pl.Pos)
+				palleteMat.SetUnifVec3(indexString+".pos", &pl.Pos)
 			}
 
 			if imgui.DragFloat3("Diffuse Color", &pl.DiffuseColor.Data) {
-				whiteMat.SetUnifVec3("pointLights["+indexString+"].diffuseColor", &pl.DiffuseColor)
-				containerMat.SetUnifVec3("pointLights["+indexString+"].diffuseColor", &pl.DiffuseColor)
-				palleteMat.SetUnifVec3("pointLights["+indexString+"].diffuseColor", &pl.DiffuseColor)
+				whiteMat.SetUnifVec3(indexString+".diffuseColor", &pl.DiffuseColor)
+				containerMat.SetUnifVec3(indexString+".diffuseColor", &pl.DiffuseColor)
+				palleteMat.SetUnifVec3(indexString+".diffuseColor", &pl.DiffuseColor)
 			}
 
 			if imgui.DragFloat3("Specular Color", &pl.SpecularColor.Data) {
-				whiteMat.SetUnifVec3("pointLights["+indexString+"].specularColor", &pl.SpecularColor)
-				containerMat.SetUnifVec3("pointLights["+indexString+"].specularColor", &pl.SpecularColor)
-				palleteMat.SetUnifVec3("pointLights["+indexString+"].specularColor", &pl.SpecularColor)
+				whiteMat.SetUnifVec3(indexString+".specularColor", &pl.SpecularColor)
+				containerMat.SetUnifVec3(indexString+".specularColor", &pl.SpecularColor)
+				palleteMat.SetUnifVec3(indexString+".specularColor", &pl.SpecularColor)
+			}
+
+			imgui.TreePop()
+		}
+
+		imgui.EndListBox()
+	}
+
+	// Spot lights
+	if imgui.BeginListBoxV("Spot Lights", imgui.Vec2{Y: 200}) {
+
+		for i := 0; i < len(spotLights); i++ {
+
+			l := &spotLights[i]
+			indexNumString := strconv.Itoa(i)
+
+			if !imgui.TreeNodeExStrV("Spot Light "+indexNumString, imgui.TreeNodeFlagsSpanAvailWidth) {
+				continue
+			}
+
+			indexString := "spotLights[" + indexNumString + "]"
+
+			if imgui.DragFloat3("Pos", &l.Pos.Data) {
+				whiteMat.SetUnifVec3(indexString+".pos", &l.Pos)
+				containerMat.SetUnifVec3(indexString+".pos", &l.Pos)
+				palleteMat.SetUnifVec3(indexString+".pos", &l.Pos)
+			}
+
+			if imgui.DragFloat3("Dir", &l.Dir.Data) {
+				whiteMat.SetUnifVec3(indexString+".dir", &l.Dir)
+				containerMat.SetUnifVec3(indexString+".dir", &l.Dir)
+				palleteMat.SetUnifVec3(indexString+".dir", &l.Dir)
+			}
+
+			if imgui.DragFloat3("Diffuse Color", &l.DiffuseColor.Data) {
+				whiteMat.SetUnifVec3(indexString+".diffuseColor", &l.DiffuseColor)
+				containerMat.SetUnifVec3(indexString+".diffuseColor", &l.DiffuseColor)
+				palleteMat.SetUnifVec3(indexString+".diffuseColor", &l.DiffuseColor)
+			}
+
+			if imgui.DragFloat3("Specular Color", &l.SpecularColor.Data) {
+				whiteMat.SetUnifVec3(indexString+".specularColor", &l.SpecularColor)
+				containerMat.SetUnifVec3(indexString+".specularColor", &l.SpecularColor)
+				palleteMat.SetUnifVec3(indexString+".specularColor", &l.SpecularColor)
+			}
+
+			if imgui.DragFloat("Inner Cutoff", &l.InnerCutoff) {
+				whiteMat.SetUnifFloat32(indexString+".innerCutoff", l.InnerCutoff)
+				containerMat.SetUnifFloat32(indexString+".innerCutoff", l.InnerCutoff)
+				palleteMat.SetUnifFloat32(indexString+".innerCutoff", l.InnerCutoff)
+			}
+
+			if imgui.DragFloat("Outer Cutoff", &l.OuterCutoff) {
+				whiteMat.SetUnifFloat32(indexString+".outerCutoff", l.OuterCutoff)
+				containerMat.SetUnifFloat32(indexString+".outerCutoff", l.OuterCutoff)
+				palleteMat.SetUnifFloat32(indexString+".outerCutoff", l.OuterCutoff)
 			}
 
 			imgui.TreePop()

res/shaders/simple.glsl

@@ -64,6 +64,18 @@ struct PointLight {
 #define NUM_POINT_LIGHTS 16
 uniform PointLight pointLights[NUM_POINT_LIGHTS];
 
+struct SpotLight {
+    vec3 pos;
+    vec3 dir;
+    vec3 diffuseColor;
+    vec3 specularColor;
+    float innerCutoff;
+    float outerCutoff;
+};
+
+#define NUM_SPOT_LIGHTS 4
+uniform SpotLight spotLights[NUM_SPOT_LIGHTS];
+
 uniform vec3 camPos;
 uniform vec3 ambientColor = vec3(0.2, 0.2, 0.2);
 
@@ -122,9 +134,33 @@ vec3 CalcPointLight(PointLight pointLight)
     return (finalDiffuse + finalSpecular) * attenuation;
 }
 
-vec3 CalcSpotLight()
+vec3 CalcSpotLight(SpotLight light)
 {
-    return vec3(0);
+    if (light.innerCutoff == 0)
+        return vec3(0);
+
+    vec3 fragToLightDir = normalize(light.pos - fragPos);
+
+    // Spot light cone with full intensity within inner cutoff,
+    // and falloff between inner-outer cutoffs, and zero
+    // light after outer cutoff
+    float theta = dot(fragToLightDir, normalize(-light.dir));
+    float epsilon = (light.innerCutoff - light.outerCutoff);
+    float intensity = clamp((theta - light.outerCutoff) / epsilon, 0.0, 1.0);
+
+    if (intensity == 0)
+        return vec3(0);
+
+    // Diffuse
+    float diffuseAmount = max(0.0, dot(normalizedVertNorm, fragToLightDir));
+    vec3 finalDiffuse = diffuseAmount * light.diffuseColor * diffuseTexColor.rgb;
+
+    // Specular
+    vec3 reflectDir = reflect(-fragToLightDir, normalizedVertNorm);
+    float specularAmount = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
+    vec3 finalSpecular = specularAmount * light.specularColor * specularTexColor.rgb;
+
+    return (finalDiffuse + finalSpecular) * intensity;
 }
 
 void main()
@@ -145,7 +181,10 @@ void main()
         finalColor += CalcPointLight(pointLights[i]);
     }
 
-    finalColor += CalcSpotLight();
+    for (int i = 0; i < NUM_SPOT_LIGHTS; i++)
+    {
+        finalColor += CalcSpotLight(spotLights[i]);
+    }
 
     vec3 finalEmission = emissionTexColor.rgb;
     vec3 finalAmbient = ambientColor * diffuseTexColor.rgb;