3Dのリングを作ろうと思ったら変なのができた。。とiPhoneアプリのサンプルコードを描いてみます。
#import “ViewController.h”
@interface ViewController ()
{
GLuint v;
int counter;
}
@property (nonatomic, strong) GLKBaseEffect *baseEffect;
@property (nonatomic, strong) GLKView *gv;
@end
@implementation ViewController
– (void)loadView
{
self.view = [[GLKView alloc] initWithFrame:CGRectMake(0, 0, 320, 568) context:[[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3]];
}
– (void)viewDidLoad
{
[super viewDidLoad];
[self setupGL];
}
– (void)setupGL
{
self.gv = (GLKView*)self.view;
self.gv.drawableColorFormat = GLKViewDrawableDepthFormat24;
[EAGLContext setCurrentContext:self.gv.context];
self.baseEffect = [[GLKBaseEffect alloc] init];
self.baseEffect.light0.enabled = GL_TRUE;
self.baseEffect.light0.diffuseColor = GLKVector4Make(1.0f, 0.4f, 0.4f, 1.0f);
self.baseEffect.light0.ambientColor = GLKVector4Make(.0f, 0.4f, 0.4f, 1.0f);
glClearColor(0.2f, 0.5f, 0.6f, 1.0f);
glGenBuffers(1, &v);
glBindBuffer(GL_ARRAY_BUFFER, v);
glBufferData(GL_ARRAY_BUFFER, sizeof(cubeVertices), cubeVertices, GL_STATIC_DRAW);
glEnableVertexAttribArray(GLKVertexAttribPosition);
glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 24, (char *)NULL + 0);
glEnableVertexAttribArray(GLKVertexAttribNormal);
glVertexAttribPointer(GLKVertexAttribNormal, 3, GL_FLOAT, GL_FALSE, 24, (char *)NULL + 12);
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
}
– (void)glkView:(GLKView *)view drawInRect:(CGRect)rect
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
const GLfloat aspectRatio = (GLfloat)view.drawableWidth / (GLfloat)view.drawableHeight;
self.baseEffect.transform.projectionMatrix = GLKMatrix4MakeScale(0.05, 0.05 * aspectRatio, 0.05);
int count = 30;
float degree = 360 / count;
for (int i=0; i<count; i++) {
GLKMatrix4 mat = GLKMatrix4Identity;
mat = GLKMatrix4Rotate(mat, GLKMathDegreesToRadians(degree * i), 0, 0, 1);
mat = GLKMatrix4Translate(mat, 5, 0, 0);
self.baseEffect.transform.modelviewMatrix = mat;
GLKMatrix4 mModelViewMatrix = GLKMatrix4MakeRotation(GLKMathDegreesToRadians(counter), 0.0f, 1.0f, 0.0f);
self.baseEffect.transform.modelviewMatrix = GLKMatrix4Multiply(mModelViewMatrix, self.baseEffect.transform.modelviewMatrix);
[self.baseEffect prepareToDraw];
glDrawArrays(GL_TRIANGLES, 0, 36);
}
counter++;
}
GLfloat cubeVertices[216] =
{
//x y z nx ny nz
1.0f, –1.0f, –1.0f, 1.0f, 0.0f, 0.0f,
1.0f, 1.0f, –1.0f, 1.0f, 0.0f, 0.0f,
1.0f, –1.0f, 1.0f, 1.0f, 0.0f, 0.0f,
1.0f, –1.0f, 1.0f, 1.0f, 0.0f, 0.0f,
1.0f, 1.0f, –1.0f, 1.0f, 0.0f, 0.0f,
1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f,
1.0f, 1.0f, –1.0f, 0.0f, 1.0f, 0.0f,
–1.0f, 1.0f, –1.0f, 0.0f, 1.0f, 0.0f,
1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f,
1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f,
–1.0f, 1.0f, –1.0f, 0.0f, 1.0f, 0.0f,
–1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f,
–1.0f, 1.0f, –1.0f, –1.0f, 0.0f, 0.0f,
–1.0f, –1.0f, –1.0f, –1.0f, 0.0f, 0.0f,
–1.0f, 1.0f, 1.0f, –1.0f, 0.0f, 0.0f,
–1.0f, 1.0f, 1.0f, –1.0f, 0.0f, 0.0f,
–1.0f, –1.0f, –1.0f, –1.0f, 0.0f, 0.0f,
–1.0f, –1.0f, 1.0f, –1.0f, 0.0f, 0.0f,
–1.0f, –1.0f, –1.0f, 0.0f, –1.0f, 0.0f,
1.0f, –1.0f, –1.0f, 0.0f, –1.0f, 0.0f,
–1.0f, –1.0f, 1.0f, 0.0f, –1.0f, 0.0f,
–1.0f, –1.0f, 1.0f, 0.0f, –1.0f, 0.0f,
1.0f, –1.0f, –1.0f, 0.0f, –1.0f, 0.0f,
1.0f, –1.0f, 1.0f, 0.0f, –1.0f, 0.0f,
1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
–1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
1.0f, –1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
1.0f, –1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
–1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
–1.0f, –1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
1.0f, –1.0f, –1.0f, 0.0f, 0.0f, –1.0f,
–1.0f, –1.0f, –1.0f, 0.0f, 0.0f, –1.0f,
1.0f, 1.0f, –1.0f, 0.0f, 0.0f, –1.0f,
1.0f, 1.0f, –1.0f, 0.0f, 0.0f, –1.0f,
–1.0f, –1.0f, –1.0f, 0.0f, 0.0f, –1.0f,
–1.0f, 1.0f, –1.0f, 0.0f, 0.0f, –1.0f
};
@end