CCEffectLighting - Add ambient color support

And add ambient color and intensity to CCLightNode. This also introduces the idea of light
types (point, spot, directional) but this isn't actually implemented in the effect yet.

Author: Thayer J Andrews

cocos2d/CCEffectLighting.m

@@ -29,10 +29,11 @@ -(id)init
     return [self initWithLight:nil];
 }
 
--(id)initWithLight:(CCNode *)light
+-(id)initWithLight:(CCLightNode *)light
 {
     NSArray *fragUniforms = @[
                               [CCEffectUniform uniform:@"vec4" name:@"u_lightColor" value:[NSValue valueWithGLKVector4:GLKVector4Make(1.0f, 1.0f, 1.0f, 1.0f)]],
+                              [CCEffectUniform uniform:@"vec4" name:@"u_ambientColor" value:[NSValue valueWithGLKVector4:GLKVector4Make(1.0f, 1.0f, 1.0f, 1.0f)]],
                               ];
 
     NSArray *vertUniforms = @[
@@ -53,7 +54,7 @@ -(id)initWithLight:(CCNode *)light
     return self;
 }
 
-+(id)effectWithLight:(CCNode *)light
++(id)effectWithLight:(CCLightNode *)light
 {
     return [[self alloc] initWithLight:light];
 }
@@ -72,7 +73,7 @@ -(void)buildFragmentFunctions
                                    float NdotL = dot(tangentSpaceNormal, v_tangentSpaceLightDir);
                                    if (normalMap.a > 0.0)
                                    {
-                                       return inputValue * u_lightColor * NdotL;
+                                       return inputValue * (u_lightColor * NdotL + u_ambientColor);
                                    }
                                    else
                                    {
@@ -123,9 +124,11 @@ -(void)buildRenderPasses
         GLKVector4 lightPosition = GLKMatrix4MultiplyVector4(lightNodeToEffectNode, GLKVector4Make(weakSelf.light.anchorPointInPoints.x, weakSelf.light.anchorPointInPoints.y, 500.0f, 1.0f));
 
         GLKVector4 lightColor = GLKVector4MultiplyScalar(weakSelf.light.color.glkVector4, weakSelf.light.intensity);
+        GLKVector4 ambientColor = GLKVector4MultiplyScalar(weakSelf.light.ambientColor.glkVector4, weakSelf.light.ambientIntensity);
 
         pass.shaderUniforms[weakSelf.uniformTranslationTable[@"u_lightColor"]] = [NSValue valueWithGLKVector4:lightColor];
         pass.shaderUniforms[weakSelf.uniformTranslationTable[@"u_lightPosition"]] = [NSValue valueWithGLKVector4:lightPosition];
+        pass.shaderUniforms[weakSelf.uniformTranslationTable[@"u_ambientColor"]] = [NSValue valueWithGLKVector4:ambientColor];
         pass.shaderUniforms[weakSelf.uniformTranslationTable[@"u_ndcToTangentSpace"]] = [NSValue valueWithGLKMatrix4:pass.ndcToNodeLocal];
 
     } copy]];

cocos2d/CCLightNode.h

@@ -8,6 +8,14 @@
 
 #import "CCNode.h"
 
+
+typedef NS_ENUM(NSUInteger, CCLightNodeType)
+{
+    CCLightNodePoint       = 0,
+    CCLightNodeDirectional = 1,
+    CCLightNodeSpot        = 2,
+};
+
 /**
  * CCLightNode allows the user to define lights that will be used with
  * CCEffectLighting.
@@ -19,27 +27,54 @@
 /// @name Accessing Node Attributes
 /// -----------------------------------------------------------------------
 
-/** The color of the light. As described below, the color is modulated by the
+/** The type of the light. The contribution of point lights is dependent on
+ *  the relative positions of the light and the node it is lighting. The
+ *  contribution of directional lights is only dependent on the light's
+ *  orientation (as if it is infinitely far away). Spot lights behave like
+ *  point lights but they also have a direction vector and cutoff angle.
+ *  If the angle between the light's direction vector and the vector from
+ *  the light to the node exceeds the cutoff angle then the light no longer
+ *  contributes to the lighting of the node.
+ */
+@property (nonatomic, assign) CCLightNodeType type;
+
+/** The primary color of the light. As described below, the color is modulated by the
  *  intensity value to determine the contribution of the light to the lighting
- *  effect.
+ *  effect. This color is used when computing the light's position and orientation
+ *  dependent contribution to the lighting effect.
  */
 @property (nonatomic, strong) CCColor* color;
 
-/** The overall brightness of the light. This value is in the range [0..1] with
- *  0 resulting in no contribution from this light in the final image (the light
+/** The brightness of the light's primary color. This value is in the range [0..1]
+ *  with 0 resulting in no contribution from this light in the final image (the light
  *  effectively becomes black) and 1 resulting in full contribution from this
- *  light (the light's full color contributes).
+ *  light.
  */
 @property (nonatomic, assign) float intensity;
 
+/** The ambient color of the light. As described below, the color is modulated by the
+ *  ambient intensity value to determine the contribution of the light to the lighting
+ *  effect. The ambient color contributes to the lighting effect independent of the light's
+ *  position and orientation relative to the affected node.
+ */
+@property (nonatomic, strong) CCColor* ambientColor;
+
+/** The brightness of the light's ambient color. This value is in the range [0..1]
+ *  with 0 resulting in no contribution from the ambient color to the final image 
+ *  (the ambient color effectively becomes black) and 1 resulting in full contribution 
+ *  from this light.
+ */
+@property (nonatomic, assign) float ambientIntensity;
+
+
 
 /// -----------------------------------------------------------------------
 /// @name Initializing a CCLightNode object
 /// -----------------------------------------------------------------------
 
 
 /**
- *  Initializes a CCLightNode object with a white color and full intensity.
+ *  Initializes a point light with a white color and full intensity.
  *
  *  @return The CCLightNode object.
  */
@@ -48,9 +83,15 @@
 /**
  *  Initializes a CCLightNode object with the specified parameters.
  *
+ *  @param type             The type of the light.
+ *  @param color            The primary color of the light.
+ *  @param intensity        The brightness of the light's primary color.
+ *  @param ambientColor     The ambient color of the light.
+ *  @param ambientIntensity The brightness of the light's ambient color.
+ *
  *  @return The CCLighttNode object.
  */
--(id)initWithColor:(CCColor *)color intensity:(float)intensity;
+-(id)initWithType:(CCLightNodeType)type color:(CCColor *)color intensity:(float)intensity ambientColor:(CCColor *)ambientColor ambientIntensity:(float)ambientIntensity;
 
 
 /// -----------------------------------------------------------------------
@@ -60,12 +101,15 @@
 /**
  *  Creates a CCLightNode object with the specified parameters.
  *
- *  @param color     Color of the light.
- *  @param intensity The overall brightness of the light.
+ *  @param type             The type of the light.
+ *  @param color            The primary color of the light.
+ *  @param intensity        The brightness of the light's primary color.
+ *  @param ambientColor     The ambient color of the light.
+ *  @param ambientIntensity The brightness of the light's ambient color.
  *
  *  @return An initialized CCLightNode object.
  */
-+(id)lightWithColor:(CCColor *)color intensity:(float)intensity;
++(id)lightWithType:(CCLightNodeType)type color:(CCColor *)color intensity:(float)intensity ambientColor:(CCColor *)ambientColor ambientIntensity:(float)ambientIntensity;
 
 
 @end

cocos2d/CCLightNode.m

@@ -8,23 +8,32 @@
 
 #import "CCLightNode.h"
 
+
 @implementation CCLightNode
 
--(id)initWithColor:(CCColor *)color intensity:(float)intensity
+-(id)init
+{
+    return [self initWithType:CCLightNodePoint color:[CCColor whiteColor] intensity:1.0f ambientColor:[CCColor whiteColor] ambientIntensity:0.5f];
+}
+
+
+-(id)initWithType:(CCLightNodeType)type color:(CCColor *)color intensity:(float)intensity ambientColor:(CCColor *)ambientColor ambientIntensity:(float)ambientIntensity
 {
     if ((self = [super init]))
     {
+        _type = type;
         _color = color.ccColor4f;
         _intensity = intensity;
+        _ambientColor = ambientColor;
+        _ambientIntensity = ambientIntensity;
     }
 
     return self;
 }
 
-+(id)lightWithColor:(CCColor *)color intensity:(float)intensity
++(id)lightWithType:(CCLightNodeType)type color:(CCColor *)color intensity:(float)intensity ambientColor:(CCColor *)ambientColor ambientIntensity:(float)ambientIntensity
 {
-    return [[self alloc] initWithColor:color intensity:intensity];
+    return [[self alloc] initWithType:type color:color intensity:intensity ambientColor:ambientColor ambientIntensity:ambientIntensity];
 }
 
-
 @end