/*

File: Fur.m

Abstract: Fur Exhibit

Author: "OpenGL Shading Language" book.

          (a.k.a "the orange book")

© Copyright 2004 Apple Computer, Inc. All rights reserved.

IMPORTANT:  This Apple software is supplied to 

you by Apple Computer, Inc. ("Apple") in 

consideration of your agreement to the following 

terms, and your use, installation, modification 

or redistribution of this Apple software 

constitutes acceptance of these terms.  If you do 

not agree with these terms, please do not use, 

install, modify or redistribute this Apple 

software.

In consideration of your agreement to abide by 

the following terms, and subject to these terms, 

Apple grants you a personal, non-exclusive 

license, under Apple's copyrights in this 

original Apple software (the "Apple Software"), 

to use, reproduce, modify and redistribute the 

Apple Software, with or without modifications, in 

source and/or binary forms; provided that if you 

redistribute the Apple Software in its entirety 

and without modifications, you must retain this 

notice and the following text and disclaimers in 

all such redistributions of the Apple Software. 

Neither the name, trademarks, service marks or 

logos of Apple Computer, Inc. may be used to 

endorse or promote products derived from the 

Apple Software without specific prior written 

permission from Apple.  Except as expressly 

stated in this notice, no other rights or 

licenses, express or implied, are granted by 

Apple herein, including but not limited to any 

patent rights that may be infringed by your 

derivative works or by other works in which the 

Apple Software may be incorporated.

The Apple Software is provided by Apple on an "AS 

IS" basis.  APPLE MAKES NO WARRANTIES, EXPRESS OR 

IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED 

WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY 

AND FITNESS FOR A PARTICULAR PURPOSE, REGARDING 

THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE 

OR IN COMBINATION WITH YOUR PRODUCTS.

IN NO EVENT SHALL APPLE BE LIABLE FOR ANY 

SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL 

DAMAGES (INCLUDING, BUT NOT LIMITED TO, 

PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 

OF USE, DATA, OR PROFITS; OR BUSINESS 

INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, 

REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION OF 

THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER 

UNDER THEORY OF CONTRACT, TORT (INCLUDING 

NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN 

IF APPLE HAS BEEN ADVISED OF THE POSSIBILITY OF 

SUCH DAMAGE.

*/

#import "Fur.h"

@implementation Fur

- (id) init

{

    [super init];

    return self;

}

- (void) initLazy

{

    [super initLazy];

    /* Setup GLSL */

    {

        NSBundle *bundle;

        NSString *string, *vertex_string, *fragment_string;

        NSBitmapImageRep *bitmapimagerep;

        NSRect rect;

        bundle = [NSBundle bundleForClass: [self class]];

        /* Create noise texture */

        glGenTextures(1, &noiseTexture);

        glBindTexture(GL_TEXTURE_2D, noiseTexture);

        string = [bundle pathForResource: @"Noise512x512xRGB" ofType: @"png"];

        bitmapimagerep = LoadImage(string, 1);

        rect = NSMakeRect(0, 0, [bitmapimagerep pixelsWide], [bitmapimagerep pixelsHigh]);

        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);

        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);   

        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, rect.size.width, rect.size.height, 0,

                         (([bitmapimagerep hasAlpha])?(GL_RGBA):(GL_RGB)), GL_UNSIGNED_BYTE, 

                         [bitmapimagerep bitmapData]);

        /* Create color Texture */

        glGenTextures(1, &colorTexture);

        glBindTexture(GL_TEXTURE_2D, colorTexture);

        string = [bundle pathForResource: @"Leopard" ofType: @"jpg"];

        bitmapimagerep = LoadImage(string, 1);

        rect = NSMakeRect(0, 0, [bitmapimagerep pixelsWide], [bitmapimagerep pixelsHigh]);

        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);

        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);   

        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, rect.size.width, rect.size.height, 0,

                         (([bitmapimagerep hasAlpha])?(GL_RGBA):(GL_RGB)), GL_UNSIGNED_BYTE, 

                         [bitmapimagerep bitmapData]);

        /* Load vertex and fragment shader */

        vertex_string   = [bundle pathForResource: @"Fur" ofType: @"vert"];

        vertex_string   = [NSString stringWithContentsOfFile: vertex_string];

        fragment_string = [bundle pathForResource: @"Fur" ofType: @"frag"];

        fragment_string = [NSString stringWithContentsOfFile: fragment_string];

        if ([self loadVertexShader: vertex_string fragmentShader: fragment_string])

            NSLog(@"Failed to load Fur");

        /* Setup uniforms */

        glUseProgramObjectARB(program_object);

        glUniform1fARB(glGetUniformLocationARB(program_object, "ambient"), 0.2);

        glUniform3fARB(glGetUniformLocationARB(program_object, "lightPosition"), 0.0, 0.0, 5.0);

        glUniform1fARB(glGetUniformLocationARB(program_object, "spacing"), 1);

        glUniform1iARB(glGetUniformLocationARB(program_object, "noiseTexture"), 0);

        glUniform1iARB(glGetUniformLocationARB(program_object, "colorTexture"), 1);

        /* Create a display list for the teapot (especially important with the number of

        teapots per frame in this shell-based approach) */

        teapotList = glGenLists(1);

        glNewList(teapotList, GL_COMPILE);

        teapot(8, 0.5, GL_FILL);

        glEndList();

    }

}

- (void) dealloc

{

    glDeleteTextures(1, &noiseTexture);

    glDeleteTextures(1, &colorTexture);

    glDeleteLists(teapotList, 1);

    [super dealloc];

}

- (NSString *) name

{

    return @"Fur";

}

- (NSString *) descriptionFilename

{

    NSBundle *bundle;

    NSString *string;

    bundle = [NSBundle bundleForClass: [self class]];

    string = [bundle pathForResource: @"Fur" ofType: @"rtf"];

    return string;

}

#define SHELLS 10

#define FUR_HEIGHT .25

#define SHELL_TRANSPARENCY .3

- (void) renderFrame

{

    int i;

    [super renderFrame];

    glPushAttrib(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_ENABLE_BIT | GL_TEXTURE_BIT | GL_CURRENT_BIT);

    glDisable(GL_TEXTURE_3D);

    glDisable(GL_TEXTURE_2D);

    glEnable(GL_LIGHTING);

    glEnable(GL_LIGHT0);

    /* Draw the skin before the fur */

    glColor3f(0.9, 0.65, 0.4);

    glEnable(GL_COLOR_MATERIAL);

    glCallList(teapotList);

    glUseProgramObjectARB(program_object);

    glColor3f(1.0, 1.0, 1.0);

    glDisable(GL_COLOR_MATERIAL);

    glActiveTexture(GL_TEXTURE0);

    glBindTexture(GL_TEXTURE_2D, noiseTexture);

    glActiveTexture(GL_TEXTURE1);

    glBindTexture(GL_TEXTURE_2D, colorTexture);

    glActiveTexture(GL_TEXTURE0);

    glEnable(GL_BLEND);

    glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    glUniform1fARB(glGetUniformLocationARB(program_object, "transparency"), 1);

    glUniform1fARB(glGetUniformLocationARB(program_object, "furHeight"), 0);

    glUniform1fARB(glGetUniformLocationARB(program_object, "transparency"), SHELL_TRANSPARENCY);

    glEnable(GL_CULL_FACE);

    for (i = 1; i < SHELLS; i++)

    {

        glUniform1fARB(glGetUniformLocationARB(program_object, "furHeight"), (float)i / (SHELLS / FUR_HEIGHT));

        glCallList(teapotList);

    }

    glUseProgramObjectARB(NULL);

    glPopAttrib();

}

- (BOOL) reflect

{

    return NO;

}

@end