GLKView Boilerplate #opengles #ios #animation #3d #boilerplate

GLKView Boilerplate.mm

//
//  AC_CoverView.m
//  AC Cover
//
//  Created by Hari Karam Singh on 11/04/2014.
//  Copyright (c) 2014 Air Craft. All rights reserved.
//

#import "AC_CoverView.h"
#import "GLKView+AC_Additions.h"

/////////////////////////////////////////////////////////////////////////
#pragma mark - GL Data & Types
/////////////////////////////////////////////////////////////////////////

#define BUFFER_OFFSET(i) ((char *)NULL + (i))

// Uniform index.
enum
{
    UNIFORM_MODELVIEWPROJECTION_MATRIX,
    UNIFORM_NORMAL_MATRIX,
    NUM_UNIFORMS
};
GLint uniforms[NUM_UNIFORMS];

// Attribute index.
enum
{
    ATTRIB_VERTEX,
    ATTRIB_NORMAL,
    NUM_ATTRIBUTES
};

GLfloat _glCubeVertexData[216] =
{
    // Data layout for each line below is:
    // positionX, positionY, positionZ,     normalX, normalY, normalZ,
    0.5f, -0.5f, -0.5f,        1.0f, 0.0f, 0.0f,
    0.5f, 0.5f, -0.5f,         1.0f, 0.0f, 0.0f,
    0.5f, -0.5f, 0.5f,         1.0f, 0.0f, 0.0f,
    0.5f, -0.5f, 0.5f,         1.0f, 0.0f, 0.0f,
    0.5f, 0.5f, -0.5f,          1.0f, 0.0f, 0.0f,
    0.5f, 0.5f, 0.5f,         1.0f, 0.0f, 0.0f,
    
    0.5f, 0.5f, -0.5f,         0.0f, 1.0f, 0.0f,
    -0.5f, 0.5f, -0.5f,        0.0f, 1.0f, 0.0f,
    0.5f, 0.5f, 0.5f,          0.0f, 1.0f, 0.0f,
    0.5f, 0.5f, 0.5f,          0.0f, 1.0f, 0.0f,
    -0.5f, 0.5f, -0.5f,        0.0f, 1.0f, 0.0f,
    -0.5f, 0.5f, 0.5f,         0.0f, 1.0f, 0.0f,
    
    -0.5f, 0.5f, -0.5f,        -1.0f, 0.0f, 0.0f,
    -0.5f, -0.5f, -0.5f,       -1.0f, 0.0f, 0.0f,
    -0.5f, 0.5f, 0.5f,         -1.0f, 0.0f, 0.0f,
    -0.5f, 0.5f, 0.5f,         -1.0f, 0.0f, 0.0f,
    -0.5f, -0.5f, -0.5f,       -1.0f, 0.0f, 0.0f,
    -0.5f, -0.5f, 0.5f,        -1.0f, 0.0f, 0.0f,
    
    -0.5f, -0.5f, -0.5f,       0.0f, -1.0f, 0.0f,
    0.5f, -0.5f, -0.5f,        0.0f, -1.0f, 0.0f,
    -0.5f, -0.5f, 0.5f,        0.0f, -1.0f, 0.0f,
    -0.5f, -0.5f, 0.5f,        0.0f, -1.0f, 0.0f,
    0.5f, -0.5f, -0.5f,        0.0f, -1.0f, 0.0f,
    0.5f, -0.5f, 0.5f,         0.0f, -1.0f, 0.0f,
    
    0.5f, 0.5f, 0.5f,          0.0f, 0.0f, 1.0f,
    -0.5f, 0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
    0.5f, -0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
    0.5f, -0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
    -0.5f, 0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
    -0.5f, -0.5f, 0.5f,        0.0f, 0.0f, 1.0f,
    
    0.5f, -0.5f, -0.5f,        0.0f, 0.0f, -1.0f,
    -0.5f, -0.5f, -0.5f,       0.0f, 0.0f, -1.0f,
    0.5f, 0.5f, -0.5f,         0.0f, 0.0f, -1.0f,
    0.5f, 0.5f, -0.5f,         0.0f, 0.0f, -1.0f,
    -0.5f, -0.5f, -0.5f,       0.0f, 0.0f, -1.0f,
    -0.5f, 0.5f, -0.5f,        0.0f, 0.0f, -1.0f
};


/////////////////////////////////////////////////////////////////////////
#pragma mark -
/////////////////////////////////////////////////////////////////////////

@implementation AC_CoverView
{
    GLuint _program;
    GLuint _vertexArray;
    GLuint _vertexBuffer;
    
    GLKMatrix4 _modelViewProjectionMatrix;
    GLKMatrix3 _normalMatrix;
    float _rotation;
    GLKBaseEffect *_effect;     ///< For the lighting
    
    CADisplayLink *_updateTimer;
}


/////////////////////////////////////////////////////////////////////////
#pragma mark - Life Cycle
/////////////////////////////////////////////////////////////////////////

- (void)setup
{
    /////////////////////////////////////////
    // CONTEXT SETUP
    /////////////////////////////////////////
    
    self.context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
    if (!self.context) {
        [NSException raise:NSGenericException format:@"Couldn't create GL Context!"];
    }
    [EAGLContext setCurrentContext:self.context];
    
    // Flags
    self.drawableDepthFormat = GLKViewDrawableDepthFormat24;

    
    /////////////////////////////////////////
    // LIGHTING SETUP
    /////////////////////////////////////////

    _effect = [GLKBaseEffect new];
    _effect.light0.enabled = GL_TRUE;
    _effect.light0.diffuseColor = GLKVector4Make(1.0f, 0.4f, 0.4f, 1.0f);
    
    
    
    /////////////////////////////////////////
    // DATA & BUFFERS
    /////////////////////////////////////////
    
    glGenVertexArraysOES(1, &_vertexArray);
    glBindVertexArrayOES(_vertexArray);
    
    glGenBuffers(1, &_vertexBuffer);
    glBindBuffer(GL_ARRAY_BUFFER, _vertexBuffer);
    glBufferData(GL_ARRAY_BUFFER, sizeof(_glCubeVertexData), _glCubeVertexData, GL_STATIC_DRAW);
    
    // Set position data
    glEnableVertexAttribArray(GLKVertexAttribPosition);
    glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat)*6, BUFFER_OFFSET(0));
    glEnableVertexAttribArray(GLKVertexAttribNormal);
    glVertexAttribPointer(GLKVertexAttribNormal, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat)*6, BUFFER_OFFSET(sizeof(GLfloat)*3));
    glBindVertexArrayOES(0);
    
    
    /////////////////////////////////////////
    // SHADERS
    /////////////////////////////////////////

    [self _loadShaders];
    
    
    /////////////////////////////////////////
    // UPDATE TIMER (TEMP???)
    /////////////////////////////////////////
    _updateTimer = [CADisplayLink displayLinkWithTarget:self selector:@selector(_update:)];
    [_updateTimer addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
    
    
    // Clear the context to be polite
    [EAGLContext setCurrentContext:nil];
}



//---------------------------------------------------------------------

- (void)dealloc
{
    [_updateTimer invalidate];
    
    [EAGLContext setCurrentContext:self.context];
    
    glDeleteBuffers(1, &_vertexBuffer);
    glDeleteVertexArraysOES(1, &_vertexArray);
    
    if (_program) {
        glDeleteProgram(_program);
        _program = 0;
    }
    
    if ([EAGLContext currentContext] == self.context) {
        [EAGLContext setCurrentContext:nil];
    }
}


//---------------------------------------------------------------------



/////////////////////////////////////////////////////////////////////////
#pragma mark - Additional Privates
/////////////////////////////////////////////////////////////////////////

- (void)_update:(CADisplayLink *)sender
{
    static NSTimeInterval lastTime = -1.0;
    NSTimeInterval now;
    now = CACurrentMediaTime();
    if (lastTime < 0) {
        lastTime = now;
        return;
    }
    NSTimeInterval timeSinceLastUpdate = now - lastTime;
    
    float aspect = fabsf(self.bounds.size.width / self.bounds.size.height);
    GLKMatrix4 projectionMatrix = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(65.0f), aspect, 0.1f, 100.0f);
    
    _effect.transform.projectionMatrix = projectionMatrix;
    
    GLKMatrix4 baseModelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, -4.0f);
    baseModelViewMatrix = GLKMatrix4Rotate(baseModelViewMatrix, _rotation, 0.0f, 1.0f, 0.0f);
    
    // Compute the model view matrix for the object rendered with GLKit
    GLKMatrix4 modelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, -1.5f);
    modelViewMatrix = GLKMatrix4Rotate(modelViewMatrix, _rotation, 1.0f, 1.0f, 1.0f);
    modelViewMatrix = GLKMatrix4Multiply(baseModelViewMatrix, modelViewMatrix);
    
    _effect.transform.modelviewMatrix = modelViewMatrix;
    
    // Compute the model view matrix for the object rendered with ES2
    modelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, 1.5f);
    modelViewMatrix = GLKMatrix4Rotate(modelViewMatrix, _rotation, 1.0f, 1.0f, 1.0f);
    modelViewMatrix = GLKMatrix4Multiply(baseModelViewMatrix, modelViewMatrix);
    
    _normalMatrix = GLKMatrix3InvertAndTranspose(GLKMatrix4GetMatrix3(modelViewMatrix), NULL);
    
    _modelViewProjectionMatrix = GLKMatrix4Multiply(projectionMatrix, modelViewMatrix);
    
    _rotation += timeSinceLastUpdate * 0.5f;
    
    lastTime = now;
    
    [self setNeedsDisplay];
}


//---------------------------------------------------------------------

- (void)drawRect:(CGRect)rect
{
    
    // @TODO Set context??  Hopefully not. Try to prevent dual GL contexts operating in order to save bandwidth
    
    glEnable(GL_DEPTH_TEST);
    
   
    glClearColor(0.65f, 0.65f, 0.65f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    
    glBindVertexArrayOES(_vertexArray);
    
    // Render the object with GLKit
    [_effect prepareToDraw];
    glDrawArrays(GL_TRIANGLES, 0, 36);
    
    // Render the object again with ES2
    glUseProgram(_program);
    
    glUniformMatrix4fv(uniforms[UNIFORM_MODELVIEWPROJECTION_MATRIX], 1, 0, _modelViewProjectionMatrix.m);
    glUniformMatrix3fv(uniforms[UNIFORM_NORMAL_MATRIX], 1, 0, _normalMatrix.m);
    
    glDrawArrays(GL_TRIANGLES, 0, 36);
}


//---------------------------------------------------------------------

/** @todo Proper exception types */
- (void)_loadShaders
{
    GLuint vertShader, fragShader;
    NSString *vertShaderPathname, *fragShaderPathname;
    
    // Create shader program.
    _program = glCreateProgram();
    
    // Create and compile vertex shader.
    vertShaderPathname = [[NSBundle mainBundle] pathForResource:@"Shader" ofType:@"vsh"];
    if (![self compileShader:&vertShader type:GL_VERTEX_SHADER file:vertShaderPathname]) {
        [NSException raise:NSGenericException format:@"Failed to compile vertex shader"];
        return;
    }
    
    // Create and compile fragment shader.
    fragShaderPathname = [[NSBundle mainBundle] pathForResource:@"Shader" ofType:@"fsh"];
    if (![self compileShader:&fragShader type:GL_FRAGMENT_SHADER file:fragShaderPathname]) {
        [NSException raise:NSGenericException format:@"Failed to compile fragment shader"];
        return;
    }
    
    // Attach vertex shader to program.
    glAttachShader(_program, vertShader);
    
    // Attach fragment shader to program.
    glAttachShader(_program, fragShader);
    
    // Bind attribute locations.
    // This needs to be done prior to linking.
    glBindAttribLocation(_program, GLKVertexAttribPosition, "position");
    glBindAttribLocation(_program, GLKVertexAttribNormal, "normal");
    
    // Link program.
    if (![self linkProgram:_program]) {
        if (vertShader) {
            glDeleteShader(vertShader);
            vertShader = 0;
        }
        if (fragShader) {
            glDeleteShader(fragShader);
            fragShader = 0;
        }
        if (_program) {
            glDeleteProgram(_program);
            _program = 0;
        }
        
        [NSException raise:NSGenericException format:@"Failed to link program: %d", _program];
        return;
    }
    
    // Get uniform locations.
    uniforms[UNIFORM_MODELVIEWPROJECTION_MATRIX] = glGetUniformLocation(_program, "modelViewProjectionMatrix");
    uniforms[UNIFORM_NORMAL_MATRIX] = glGetUniformLocation(_program, "normalMatrix");
    
    // Release vertex and fragment shaders.
    if (vertShader) {
        glDetachShader(_program, vertShader);
        glDeleteShader(vertShader);
    }
    if (fragShader) {
        glDetachShader(_program, fragShader);
        glDeleteShader(fragShader);
    }
}





@end