f332206b2b886011c1b27417f8b8c76731910ff5.svn-base
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#import "GPUImageGlassSphereFilter.h"
#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
NSString *const kGPUImageGlassSphereFragmentShaderString = SHADER_STRING
(
varying highp vec2 textureCoordinate;
uniform sampler2D inputImageTexture;
uniform highp vec2 center;
uniform highp float radius;
uniform highp float aspectRatio;
uniform highp float refractiveIndex;
// uniform vec3 lightPosition;
const highp vec3 lightPosition = vec3(-0.5, 0.5, 1.0);
const highp vec3 ambientLightPosition = vec3(0.0, 0.0, 1.0);
void main()
{
highp vec2 textureCoordinateToUse = vec2(textureCoordinate.x, (textureCoordinate.y * aspectRatio + 0.5 - 0.5 * aspectRatio));
highp float distanceFromCenter = distance(center, textureCoordinateToUse);
lowp float checkForPresenceWithinSphere = step(distanceFromCenter, radius);
distanceFromCenter = distanceFromCenter / radius;
highp float normalizedDepth = radius * sqrt(1.0 - distanceFromCenter * distanceFromCenter);
highp vec3 sphereNormal = normalize(vec3(textureCoordinateToUse - center, normalizedDepth));
highp vec3 refractedVector = 2.0 * refract(vec3(0.0, 0.0, -1.0), sphereNormal, refractiveIndex);
refractedVector.xy = -refractedVector.xy;
highp vec3 finalSphereColor = texture2D(inputImageTexture, (refractedVector.xy + 1.0) * 0.5).rgb;
// Grazing angle lighting
highp float lightingIntensity = 2.5 * (1.0 - pow(clamp(dot(ambientLightPosition, sphereNormal), 0.0, 1.0), 0.25));
finalSphereColor += lightingIntensity;
// Specular lighting
lightingIntensity = clamp(dot(normalize(lightPosition), sphereNormal), 0.0, 1.0);
lightingIntensity = pow(lightingIntensity, 15.0);
finalSphereColor += vec3(0.8, 0.8, 0.8) * lightingIntensity;
gl_FragColor = vec4(finalSphereColor, 1.0) * checkForPresenceWithinSphere;
}
);
#else
NSString *const kGPUImageGlassSphereFragmentShaderString = SHADER_STRING
(
varying vec2 textureCoordinate;
uniform sampler2D inputImageTexture;
uniform vec2 center;
uniform float radius;
uniform float aspectRatio;
uniform float refractiveIndex;
// uniform vec3 lightPosition;
const vec3 lightPosition = vec3(-0.5, 0.5, 1.0);
const vec3 ambientLightPosition = vec3(0.0, 0.0, 1.0);
void main()
{
vec2 textureCoordinateToUse = vec2(textureCoordinate.x, (textureCoordinate.y * aspectRatio + 0.5 - 0.5 * aspectRatio));
float distanceFromCenter = distance(center, textureCoordinateToUse);
float checkForPresenceWithinSphere = step(distanceFromCenter, radius);
distanceFromCenter = distanceFromCenter / radius;
float normalizedDepth = radius * sqrt(1.0 - distanceFromCenter * distanceFromCenter);
vec3 sphereNormal = normalize(vec3(textureCoordinateToUse - center, normalizedDepth));
vec3 refractedVector = 2.0 * refract(vec3(0.0, 0.0, -1.0), sphereNormal, refractiveIndex);
refractedVector.xy = -refractedVector.xy;
vec3 finalSphereColor = texture2D(inputImageTexture, (refractedVector.xy + 1.0) * 0.5).rgb;
// Grazing angle lighting
float lightingIntensity = 2.5 * (1.0 - pow(clamp(dot(ambientLightPosition, sphereNormal), 0.0, 1.0), 0.25));
finalSphereColor += lightingIntensity;
// Specular lighting
lightingIntensity = clamp(dot(normalize(lightPosition), sphereNormal), 0.0, 1.0);
lightingIntensity = pow(lightingIntensity, 15.0);
finalSphereColor += vec3(0.8, 0.8, 0.8) * lightingIntensity;
gl_FragColor = vec4(finalSphereColor, 1.0) * checkForPresenceWithinSphere;
}
);
#endif
@implementation GPUImageGlassSphereFilter
#pragma mark -
#pragma mark Initialization and teardown
- (id)init;
{
if (!(self = [super initWithFragmentShaderFromString:kGPUImageGlassSphereFragmentShaderString]))
{
return nil;
}
return self;
}
@end