/*

File: Life.m

Abstract: Life Exhibit

 Disclaimer: 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.

  Copyright (c) 2004-2006 Apple Computer, Inc., All rights reserved.

*/

#import "Life.h"

@implementation Life

- (id) init

{

    [super init];

    return self;

}

- (void) initLazy

{

    [super initLazy];

    /* Setup GLSL */

   {

      NSBundle *bundle;

      NSString *fragment_string;

      NSString *vertex_string;

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

        /* frameBuffer texture */

        glGenTextures(1, &currentGeneration);

        glBindTexture(GL_TEXTURE_2D, currentGeneration);

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, lifeTextureWidth, lifeTextureHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);

        /* Load vertex and fragment shader */

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

        vertex_string = [NSString stringWithContentsOfFile: vertex_string];

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

        fragment_string = [NSString stringWithContentsOfFile: fragment_string];

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

            NSLog(@"Failed to load Life");

        /* Setup uniforms */

        glUseProgramObjectARB(program_object);

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

        lifeTextureWidth = 0;

        lifeTextureHeight = 0;

        [self updateSimulationDimensions];

    }

}

- (void) dealloc

{

    [super dealloc];

    glDeleteTextures(1, &currentGeneration);

}

- (NSString *) name

{

    return @"Life";

}

- (NSString *) descriptionFilename

{

    NSBundle *bundle;

    NSString *string;

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

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

    return string;

}

- (void) updateSimulationDimensions

{

    GLint viewport[4];

    glGetIntegerv(GL_VIEWPORT, viewport);

    //resize the life texture if need-be

    int newLifeTextureWidth;

    int newLifeTextureHeight;

    newLifeTextureWidth = NextHighestPowerOf2(viewport[2]);

    newLifeTextureHeight = NextHighestPowerOf2(viewport[3]);

    if (newLifeTextureWidth != lifeTextureWidth || newLifeTextureHeight != lifeTextureHeight)

    {

        CopyFramebufferToTexture(currentGeneration);

        lifeTextureWidth = newLifeTextureWidth;

        lifeTextureHeight = newLifeTextureHeight;

        //tell the GLSL program how big the life texture is

        glUniform4fARB(glGetUniformLocationARB(program_object, "pixelDimension"), 1.0/lifeTextureWidth, -1.0/lifeTextureWidth, 1.0/lifeTextureHeight, -1.0/lifeTextureHeight);

    }

}

- (void) renderFrame

{

    [super renderFrame];

    glPushAttrib(GL_TRANSFORM_BIT | GL_TEXTURE_BIT | GL_ENABLE_BIT);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    //bind the current life generation

    glBindTexture(GL_TEXTURE_2D, currentGeneration);

    //set up our matrices

    {

        glMatrixMode(GL_PROJECTION);

        glPushMatrix();

        glLoadIdentity();

        GLint viewport[4];

        glGetIntegerv(GL_VIEWPORT, viewport);

        glOrtho(0, viewport[2], 0, viewport[3], 1, -1);

        {

            glMatrixMode(GL_MODELVIEW);

            glPushMatrix();

            glLoadIdentity();

            glUseProgramObjectARB(program_object);

            //compute the part of the power-of-two life texture we care about

            double useableTextureS, useableTextureT;

            useableTextureS = (double)viewport[2] / (double)lifeTextureWidth;

            useableTextureT = (double)viewport[3] / (double)lifeTextureHeight;

            //render a quad the size of the viewport which will end up being the next life generation!

            glBegin(GL_TRIANGLES);

            glTexCoord2d(0, 0);

            glVertex2d(0, 0);

            glTexCoord2d(useableTextureS, 0);

            glVertex2d(viewport[2], 0);

            glTexCoord2d(useableTextureS, useableTextureT);

            glVertex2d(viewport[2], viewport[3]);

            glTexCoord2d(useableTextureS, useableTextureT);

            glVertex2d(viewport[2], viewport[3]);

            glTexCoord2d(0, useableTextureT);

            glVertex2d(0, viewport[3]);

            glTexCoord2d(0, 0);

            glVertex2d(0, 0);

            glEnd();

            [self updateSimulationDimensions];

            //copy this next generation back to the currentGeneration texture

            CopyFramebufferToTexture(currentGeneration);

            glUseProgramObjectARB(NULL);

            //restore matrices

            glMatrixMode(GL_MODELVIEW);

            glPopMatrix();

        }

        glMatrixMode(GL_PROJECTION);

        glPopMatrix();

    }

    glPopAttrib();

}

- (BOOL) reflect

{

    /* Life can not be reflected (upon) */

    return NO;

}

@end