//
//  Effects.m
//  DiceRoller
//
//  Created by Jacques Questiaux on 2012/06/18.
//  Copyright (c) 2012 j.questiaux@gmail.com. All rights reserved.
//

#import "Effects.h"

@interface Effects (){

}

@end


@implementation Effects

- (id) init {
    
    if([super init]){
        
        cameraLookAt = GLKVector3Make(0, 0, 0);
        cameraUp = GLKVector3Make(0, 1, 0);
        
        lightPosition = GLKVector3Make(1, 1, 3);
        lightDiffuseColour = GLKVector4Make(0.7, 0.7, 0.7, 1);
        lightSpecularColour = GLKVector4Make(2, 2, 2, 1);
        lightAmbientColour = GLKVector4Make(0.85, 0.85, 0.85, 1);
        numberColour = GLKVector4Make(0, 0, 0, 1);
        faceColour = GLKVector4Make(1, 1, 1, 1);
        
        outlineColour = GLKVector4Make(1, 0, 0, 1);
        
        [self setupTexture];
        [self loadShaders];
        [self loadToonShaders];
        
        return self;
    }
    
    return nil;
}

- (void) prepareToDraw {
    
    glUseProgram(TexAndLighting);
    
    camModelViewMatrix = GLKMatrix4Multiply(cameraMatrix, modelViewMatrix);
    
    modelViewProjectionMatrix = GLKMatrix4Multiply(projectionMatrix, camModelViewMatrix);
    
    GLKMatrix3 normalMatrix = GLKMatrix3InvertAndTranspose(GLKMatrix4GetMatrix3(modelViewMatrix), NULL);
    
    glUniformMatrix4fv(uniforms[UNIFORM_MODELVIEWPROJECTION_MATRIX], 1, 0, modelViewProjectionMatrix.m);
    glUniformMatrix3fv(uniforms[UNIFORM_NORMAL_MATRIX], 1, 0, normalMatrix.m);
    
    
    float* lp = [self vec3ToFloat:lightPosition];
    glUniform3fv(uniforms[UNIFORM_VEC3_lightPosition], 1, lp);
    delete lp;
    
    float* ldc = [self vec4ToFloat:lightDiffuseColour];
    glUniform4fv(uniforms[UNIFORM_VEC4_lightDiffuseColour], 1, ldc);
    delete ldc;
    
    float* lsc = [self vec4ToFloat:lightSpecularColour];
    glUniform4fv(uniforms[UNIFORM_VEC4_lightSpecularColour], 1, lsc);
    delete lsc;
    
    GLKVector3 lightHalfVec = GLKVector3Normalize(GLKVector3Add(cameraPosition, lightPosition));
    float* lhv = [self vec3ToFloat:lightHalfVec];
    glUniform3fv(uniforms[UNIFORM_VEC3_lightHalfVector], 1, lhv);
    delete lhv;
    
    float* nc = [self vec4ToFloat:numberColour];
    glUniform4fv(uniforms[UNIFORM_VEC4_NumberColour], 1, nc);
    delete nc;
    
    float* fc = [self vec4ToFloat:faceColour];
    glUniform4fv(uniforms[UNIFORM_VEC4_FaceColour], 1, fc);
    delete fc;

    
    glActiveTexture(GL_TEXTURE0); 
    glBindTexture(GL_TEXTURE_2D, texture);
    glUniform1i(uniforms[UNIFORM_Texture], 0);
}

- (void) drawOutline {
    
    glUseProgram(Toon);
    
    camModelViewMatrix = GLKMatrix4Multiply(cameraMatrix, modelViewMatrix);
    
    modelViewProjectionMatrix = GLKMatrix4Multiply(projectionMatrix, camModelViewMatrix);;
    
    glUniformMatrix4fv(toon_mvp, 1, 0, modelViewProjectionMatrix.m);
    
    float* oc = [self vec4ToFloat:outlineColour];
    glUniform4fv(toon_outline, 1, oc);
    delete oc;
}

- (void) setCameraPosition:(GLKVector3)cp {
    
    cameraPosition = cp;
    
    cameraMatrix = GLKMatrix4MakeLookAt(cameraPosition.x, cameraPosition.y, cameraPosition.z, cameraLookAt.x, cameraLookAt.y, cameraLookAt.z, cameraUp.x, cameraUp.y, cameraUp.z);
    
    //cameraMatrix = GLKMatrix4MakeTranslation(cameraPosition.x, cameraPosition.y, cameraPosition.z);
}

- (GLKVector3) cameraPosition {
    
    return cameraPosition;
}

- (void) setCameraLookAt:(GLKVector3)cla {
    
    cameraLookAt = cla;
    
    cameraMatrix = GLKMatrix4MakeLookAt(cameraPosition.x, cameraPosition.y, cameraPosition.z, cameraLookAt.x, cameraLookAt.y, cameraLookAt.z, cameraUp.x, cameraUp.y, cameraUp.z);
}

- (GLKVector3) cameraLookAt {
    
    return cameraLookAt;
}

- (void) setupTexture {    
    
    CGImageRef spriteImage = [UIImage imageNamed:@"texture.png"].CGImage;

    if (!spriteImage) {
        NSLog(@"Failed to load image");
        //exit(1);
    }
    
    size_t width = CGImageGetWidth(spriteImage);
    size_t height = CGImageGetHeight(spriteImage);
    
    GLubyte * spriteData = (GLubyte *) calloc(width*height*4, sizeof(GLubyte));
    CGContextRef spriteContext = CGBitmapContextCreate(spriteData, width, height, 8, width*4, CGImageGetColorSpace(spriteImage), kCGImageAlphaPremultipliedLast);    
    CGContextDrawImage(spriteContext, CGRectMake(0, 0, width, height), spriteImage);
    CGContextRelease(spriteContext);
    
    //texture gets read in upside down, need to manually flip it
    GLubyte * spriteData2 = (GLubyte *) calloc(width*height*4, sizeof(GLubyte));
    
    for(int i = 0; i < width*4; i++){
        for(int j = 0; j < height; j++){
            
            spriteData2[j*width*4+i] = spriteData[(height-1-j)*width*4+i];
            
        }
    }

    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);
    
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); //IMPORTANT FOR NON POWER OF 2 TEXTURES
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, spriteData2);
    
    free(spriteData);    
    free(spriteData2);
    
    
    //texture = texName;    
}

- (BOOL)loadShaders
{
    
    GLuint vertShader, fragShader;
    NSString *vertShaderPathname, *fragShaderPathname;
    
    // Create shader program.
    TexAndLighting = glCreateProgram();
    
    // Create and compile vertex shader.
    vertShaderPathname = [[NSBundle mainBundle] pathForResource:@"Shader" ofType:@"vsh"];
    
    if (![self compileShader:&vertShader type:GL_VERTEX_SHADER file:vertShaderPathname]) {
        NSLog(@"Failed to compile vertex shader");
        return NO;
    }
    
    // Create and compile fragment shader.
    fragShaderPathname = [[NSBundle mainBundle] pathForResource:@"Shader" ofType:@"fsh"];
    if (![self compileShader:&fragShader type:GL_FRAGMENT_SHADER file:fragShaderPathname]) {
        NSLog(@"Failed to compile fragment shader");
        return NO;
    }
    
    // Attach vertex shader to program.
    glAttachShader(TexAndLighting, vertShader);
    
    // Attach fragment shader to program.
    glAttachShader(TexAndLighting, fragShader);
    
    // Bind attribute locations.
    // This needs to be done prior to linking.
    //glBindAttribLocation(_program, ATTRIB_VERTEX, "position");
    //glBindAttribLocation(_program, ATTRIB_NORMAL, "normal");
    
    
    // Link program.
    if (![self linkProgram:TexAndLighting]) {
        NSLog(@"Failed to link program: %d", TexAndLighting);
        
        if (vertShader) {
            glDeleteShader(vertShader);
            vertShader = 0;
        }
        if (fragShader) {
            glDeleteShader(fragShader);
            fragShader = 0;
        }
        if (TexAndLighting) {
            glDeleteProgram(TexAndLighting);
            TexAndLighting = 0;
        }
        
        return NO;
    }
    
    // Get uniform locations.
    uniforms[UNIFORM_MODELVIEWPROJECTION_MATRIX] = glGetUniformLocation(TexAndLighting, "modelViewProjectionMatrix");
    uniforms[UNIFORM_NORMAL_MATRIX] = glGetUniformLocation(TexAndLighting, "normalMatrix");
    uniforms[UNIFORM_VEC3_lightPosition] = glGetUniformLocation(TexAndLighting, "lightPosition");
    uniforms[UNIFORM_VEC4_lightDiffuseColour] = glGetUniformLocation(TexAndLighting, "lightDiffuseColour");
    uniforms[UNIFORM_VEC4_lightSpecularColour] = glGetUniformLocation(TexAndLighting, "lightSpecularColour");
    uniforms[UNIFORM_VEC4_lightAmbientColour] = glGetUniformLocation(TexAndLighting, "lightAmbientColour");
    uniforms[UNIFORM_VEC3_lightHalfVector] = glGetUniformLocation(TexAndLighting, "lightHalfVector");
    uniforms[UNIFORM_Texture] = glGetUniformLocation(TexAndLighting, "Texture");
    uniforms[UNIFORM_VEC4_NumberColour] = glGetUniformLocation(TexAndLighting, "numberColour");
    uniforms[UNIFORM_VEC4_FaceColour] = glGetUniformLocation(TexAndLighting, "faceColour");
    
    texCoord = glGetAttribLocation(TexAndLighting, "TexCoordIn");
    vertCoord = glGetAttribLocation(TexAndLighting, "position");
    normal = glGetAttribLocation(TexAndLighting, "normal");
    //glEnableVertexAttribArray(texCoord);
    
    
    // Release vertex and fragment shaders.
    if (vertShader) {
        glDetachShader(TexAndLighting, vertShader);
        glDeleteShader(vertShader);
    }
    if (fragShader) {
        glDetachShader(TexAndLighting, fragShader);
        glDeleteShader(fragShader);
    }
    
    return YES;
}

- (BOOL)loadToonShaders
{
    
    GLuint vertShader, fragShader;
    NSString *vertShaderPathname, *fragShaderPathname;
    
    // Create shader program.
    Toon = glCreateProgram();
    
    // Create and compile vertex shader.
    vertShaderPathname = [[NSBundle mainBundle] pathForResource:@"Toon" ofType:@"vsh"];
    
    if (![self compileShader:&vertShader type:GL_VERTEX_SHADER file:vertShaderPathname]) {
        NSLog(@"Failed to compile vertex shader");
        return NO;
    }
    
    // Create and compile fragment shader.
    fragShaderPathname = [[NSBundle mainBundle] pathForResource:@"Toon" ofType:@"fsh"];
    if (![self compileShader:&fragShader type:GL_FRAGMENT_SHADER file:fragShaderPathname]) {
        NSLog(@"Failed to compile fragment shader");
        return NO;
    }
    
    // Attach vertex shader to program.
    glAttachShader(Toon, vertShader);
    
    // Attach fragment shader to program.
    glAttachShader(Toon, fragShader);
    
    // Bind attribute locations.
    // This needs to be done prior to linking.
    //glBindAttribLocation(Toon, vertCoord, "position");
    //glBindAttribLocation(_program, effect->normal, "normal");
    
    
    // Link program.
    if (![self linkProgram:Toon]) {
        NSLog(@"Failed to link program: %d", Toon);
        
        if (vertShader) {
            glDeleteShader(vertShader);
            vertShader = 0;
        }
        if (fragShader) {
            glDeleteShader(fragShader);
            fragShader = 0;
        }
        if (Toon) {
            glDeleteProgram(Toon);
            Toon = 0;
        }
        
        return NO;
    }
    
    // Get uniform locations.
    toon_mvp = glGetUniformLocation(Toon, "modelViewProjectionMatrix");
    toon_outline = glGetUniformLocation(Toon, "outlineColour");
    
    toon_vertCoord = glGetAttribLocation(Toon, "position");
    
    
    // Release vertex and fragment shaders.
    if (vertShader) {
        glDetachShader(Toon, vertShader);
        glDeleteShader(vertShader);
    }
    if (fragShader) {
        glDetachShader(Toon, fragShader);
        glDeleteShader(fragShader);
    }
    
    return YES;
}

- (BOOL)compileShader:(GLuint *)shader type:(GLenum)type file:(NSString *)file
{
    GLint status;
    const GLchar *source;
    
    source = (GLchar *)[[NSString stringWithContentsOfFile:file encoding:NSUTF8StringEncoding error:nil] UTF8String];
    if (!source) {
        NSLog(@"Failed to load vertex shader");
        return NO;
    }
    
    *shader = glCreateShader(type);
    glShaderSource(*shader, 1, &source, NULL);
    glCompileShader(*shader);
    
#if defined(DEBUG)
    GLint logLength;
    glGetShaderiv(*shader, GL_INFO_LOG_LENGTH, &logLength);
    if (logLength > 0) {
        GLchar *log = (GLchar *)malloc(logLength);
        glGetShaderInfoLog(*shader, logLength, &logLength, log);
        NSLog(@"Shader compile log:\n%s", log);
        free(log);
    }
#endif
    
    glGetShaderiv(*shader, GL_COMPILE_STATUS, &status);
    if (status == 0) {
        glDeleteShader(*shader);
        return NO;
    }
    
    return YES;
}

- (BOOL)linkProgram:(GLuint)prog
{
    GLint status;
    glLinkProgram(prog);
    
#if defined(DEBUG)
    GLint logLength;
    glGetProgramiv(prog, GL_INFO_LOG_LENGTH, &logLength);
    if (logLength > 0) {
        GLchar *log = (GLchar *)malloc(logLength);
        glGetProgramInfoLog(prog, logLength, &logLength, log);
        NSLog(@"Program link log:\n%s", log);
        free(log);
    }
#endif
    
    glGetProgramiv(prog, GL_LINK_STATUS, &status);
    if (status == 0) {
        return NO;
    }
    
    return YES;
}

- (BOOL)validateProgram:(GLuint)prog
{
    GLint logLength, status;
    
    glValidateProgram(prog);
    glGetProgramiv(prog, GL_INFO_LOG_LENGTH, &logLength);
    if (logLength > 0) {
        GLchar *log = (GLchar *)malloc(logLength);
        glGetProgramInfoLog(prog, logLength, &logLength, log);
        NSLog(@"Program validate log:\n%s", log);
        free(log);
    }
    
    glGetProgramiv(prog, GL_VALIDATE_STATUS, &status);
    if (status == 0) {
        return NO;
    }
    
    return YES;
}

- (float*) vec3ToFloat: (GLKVector3) v {
    float * f = new float[3];
    f[0] = v.x;
    f[1] = v.y;
    f[2] = v.z;
    
    return f;
}

- (float*) vec4ToFloat: (GLKVector4) v {
    float * f = new float[4];
    f[0] = v.x;
    f[1] = v.y;
    f[2] = v.z;
    f[3] = v.w;
    
    return f;
}

@end