Ios OpenGL ES顶点数组对象和奇怪的工件

我正在渲染一个场景，每当方向发生变化时，都必须重建该场景，以便适当地填充屏幕。场景渲染规则颜色四边形的几个顶点数组对象和纹理顶点数组对象数组。所有这些绘图元素（包括任何着色器和相关的顶点数组、索引等）都包含在一个类中，因此每次我都会吹走这个类，并在旋转时执行一个新的alloc/init

第一次创建场景时，一切看起来都很好。然而，由于某些原因，并且没有明显的模式，奇怪的三角形可能会出现在任何后续的旋转中。对于特定场景，事件似乎在每次加载时都是确定的。然而，从一个场景到另一个场景，有时会出现人工制品，有时一切看起来都很可爱

我不知道这是我如何打破我的记忆（即使在ARC中，我也需要释放一些），还是我如何创建我的VAO。但是，由于问题只发生在我拆下场景并重建它时。。。然后我又开始用这个思维过程来旋转我的轮子

我有相当多的代码，所以这里有一些（希望）相关的代码

下面是一些彩色四联VAO的绘图代码。我正在向NSMutableArray添加顶点，因为我不知道将有多少个四边形

- (void) buildNode : (NSDictionary *) nodeDictionary
            bounds : (BoundsGL) bounds
{
    if (!nodeDictionary)
    {
        return;
    }

    NSString *jobidstr = [nodeDictionary objectForKey:kNodeJobidKey];
    NSInteger jobid = jobidstr == NULL ? -1 : [jobidstr intValue];

    NSString *colorHexStr = [nodeDictionary objectForKey:kNodeColorKey];
    ColorGL color = HexidecimalStringToColorGL(colorHexStr);


    //
    // indices

    [_coloredQuadIndices addObject:[NSNumber numberWithInt:_coloredQuadVertices.count]];
    [_coloredQuadIndices addObject:[NSNumber numberWithInt:_coloredQuadVertices.count+1]];
    [_coloredQuadIndices addObject:[NSNumber numberWithInt:_coloredQuadVertices.count+2]];
    [_coloredQuadIndices addObject:[NSNumber numberWithInt:_coloredQuadVertices.count+2]];
    [_coloredQuadIndices addObject:[NSNumber numberWithInt:_coloredQuadVertices.count+1]];
    [_coloredQuadIndices addObject:[NSNumber numberWithInt:_coloredQuadVertices.count+3]];


    //
    // vertices

    GLfloat x2 = bounds.pos.x + bounds.size.w;
    GLfloat y2 = bounds.pos.y + bounds.size.h;

    PointGL blp = {bounds.pos.x, bounds.pos.y};
    PointGL brp = {x2, bounds.pos.y};
    PointGL tlp = {bounds.pos.x, y2};
    PointGL trp = {x2, y2};

    ColoredVertex bl = { .pos = blp, .color = color };
    ColoredVertex br = { .pos = brp, .color = color };
    ColoredVertex tl = { .pos = tlp, .color = color };
    ColoredVertex tr = { .pos = trp, .color = color };

    NSValue *tlv = [NSValue valueWithBytes:&tl objCType:@encode(ColoredVertex)];
    NSValue *blv = [NSValue valueWithBytes:&bl objCType:@encode(ColoredVertex)];
    NSValue *trv = [NSValue valueWithBytes:&tr objCType:@encode(ColoredVertex)];
    NSValue *brv = [NSValue valueWithBytes:&br objCType:@encode(ColoredVertex)];
    [_coloredQuadVertices addObject:tlv];
    [_coloredQuadVertices addObject:blv];
    [_coloredQuadVertices addObject:trv];
    [_coloredQuadVertices addObject:brv];
}

一些用于为纹理四边形创建VAO的代码：

#import "TexturedQuadVAO.h"
#import "Texture.h"
#import "ShaderUtil.h"

@interface TexturedQuadVAO()
{
    GLuint _textureUniformLocation;
}

@property (strong, nonatomic) Texture *texture;

@end


@implementation TexturedQuadVAO

@synthesize vaoid = _vaoid;

@synthesize vertexBuffer = _vertexBuffer;
@synthesize vcount = _vcount;
@synthesize vsize = _vsize;

@synthesize indexBuffer = _indexBuffer;
@synthesize icount = _icount;
@synthesize isize = _isize;

@synthesize texture = _texture;

- (id) initWithData : (TexturedVertex *) vertices
   numberOfVertices : (NSUInteger) vcount
       verticesSize : (size_t) vsize
            indices : (GLushort *) indices
    numberOfIndices : (NSUInteger) icount
        indicesSize : (size_t) isize
           viewSize : (CGSize) viewSize
               text : (NSString *) text
        textureSize : (SizeGL) textureSize
    foregroundColor : (UIColor *) fgcolor
    backgroundColor : (UIColor *) bgcolor
textureUniformLocation : (GLuint) textureUniformLocation
{
    self = [super init];

    if (self)
    {
        //
        // geometry

        self.vcount = vcount;
        self.vsize = vsize;

        self.icount = icount;
        self.isize = isize;


        //
        // texture

        self.texture = [[Texture alloc] init];
        UIFont *font = [UIFont fontWithName:@"Arial" size:24];
        SizeGL tSize = {textureSize.w * 2.5, textureSize.h * 2.5};
        UIImage *img = createTextImage(viewSize, text, tSize, font, fgcolor, bgcolor);

        [self.texture setupTextureWithImage:img];


        //
        // for shaders
        _textureUniformLocation = textureUniformLocation;


        [self createVertexArrayObject:vertices indices:indices];
    }

    return self;
}

- (void) createVertexArrayObject : (TexturedVertex *) vertices
                         indices : (GLushort *) indices
{
    checkGLError(@"  TexturedQuadVAO createVertexArrayObject ");

    // vertex array object

    glGenVertexArraysOES(1, &_vaoid);
    glBindVertexArrayOES(_vaoid);


    //
    // vertices buffer

    GLuint vb;
    glGenBuffers(1, &vb);
    self.vertexBuffer = vb;
    glBindBuffer(GL_ARRAY_BUFFER, self.vertexBuffer);
    glBufferData(GL_ARRAY_BUFFER, self.vsize, vertices, GL_STATIC_DRAW);   // copy data into buffer object

    // position vertex attribute
    glEnableVertexAttribArray(GLKVertexAttribPosition);
    glVertexAttribPointer(GLKVertexAttribPosition, 2, GL_FLOAT, GL_FALSE, sizeof(TexturedVertex), (const GLvoid *) offsetof(TexturedVertex, pos));

    // color vertex attribute
    glEnableVertexAttribArray(GLKVertexAttribColor);
    glVertexAttribPointer(GLKVertexAttribColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(TexturedVertex), (const GLvoid *) offsetof(TexturedVertex, color));

    // textures vertex attribute
    glEnableVertexAttribArray(GLKVertexAttribTexCoord0);
    glVertexAttribPointer(GLKVertexAttribTexCoord0, 2, GL_FLOAT, GL_FALSE, sizeof(TexturedVertex), (const GLvoid  *) offsetof(TexturedVertex, texcoord));


    //
    // index data buffer

    GLuint ib;
    glGenBuffers(1, &ib);
    self.indexBuffer = ib;
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, self.indexBuffer);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, self.isize, indices, GL_STATIC_DRAW); // copy index data into buffer object


    //
    // clear binds

    glBindVertexArrayOES(0);        // ok to unbind for now, and bind when we want to render
    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
    checkGLError(@"2 TexturedQuadVAO createVertexArrayObject ");
}

- (void) render
{
    checkGLError(@"  TexturedQuadVAO ");

    glBindVertexArrayOES(_vaoid);
    checkGLError(@"2 TexturedQuadVAO ");

    glActiveTexture(GL_TEXTURE0);
    checkGLError(@"3 TexturedQuadVAO ");

    [self.texture bind];
    checkGLError(@"4 TexturedQuadVAO ");

    glUniform1i(_textureUniformLocation, 0);
    checkGLError(@"5 TexturedQuadVAO ");

    //glDrawElements(GL_TRIANGLE_STRIP, self.vsize/sizeof(GLshort), GL_UNSIGNED_SHORT, 0);
    glDrawElements(GL_TRIANGLE_STRIP, self.vsize/sizeof(GLushort), GL_UNSIGNED_SHORT, 0);
    checkGLError(@"6 TexturedQuadVAO ");

    [self.texture unbind];
    checkGLError(@"7 TexturedQuadVAO ");

    glBindVertexArrayOES(0);
    checkGLError(@"8 TexturedQuadVAO ");
}

- (void) tearDown
{
    [self.texture deleteTexture];

    glDeleteBuffers(1, &_vertexBuffer);
    glDeleteBuffers(1, &_indexBuffer);
    glDeleteVertexArraysOES(1, &_vaoid);
}

@end

我的拆卸代码：

- (void) tearDown
{
    // VAOs

    for (int i=0; i<_texturedQuadArray.count; i++)
    {
        TexturedVAO *vao = [_texturedQuadArray objectAtIndex:i];
        [vao tearDown];
        vao = nil;
    }
    [_texturedQuadArray removeAllObjects];

    if (_coloredQuadVAO)
    {
       [_coloredQuadVAO tearDown];
       _coloredQuadVAO = nil;
    }

    if (_coloredQuadOutlinesVAO)
    {
       [_coloredQuadOutlinesVAO tearDown];
       _coloredQuadOutlinesVAO = nil;
    }

    // shaders

    if (_shaders.colorShader)
    {
       glDeleteProgram(_shaders.colorShader);
       _shaders.colorShader = 0;
    }

    if (_shaders.textureShader)
    {
       glDeleteProgram(_shaders.textureShader);
       _shaders.textureShader = 0;
    }

    checkGLError(@"Main tearDown");
}

在我注意到这一混乱的计算之前，我对这一行进行了无数次的思考，并立即将其更改为：

glDrawElements(GL_TRIANGLE_STRIP, self.icount, GL_UNSIGNED_SHORT, 0);

glDrawElements(GL_TRIANGLE_STRIP, self.icount, GL_UNSIGNED_SHORT, 0);

---

i、 我把计数改为实际的印度计数。

正如我所想，这是一件难以置信的小事，我花了这么多天的时间试图找到——在所有错误的地方

罪魁祸首是TexturedQuadVAOs第二组代码中的这一行：

在我注意到这一混乱的计算之前，我对这一行进行了无数次的思考，并立即将其更改为：

glDrawElements(GL_TRIANGLE_STRIP, self.icount, GL_UNSIGNED_SHORT, 0);

glDrawElements(GL_TRIANGLE_STRIP, self.icount, GL_UNSIGNED_SHORT, 0);

---

i、 e.我将计数改为实际的指示器计数。

所以现在一切看起来都很好，因为流式数据改变了场景。这几乎就好像四边形的放置与出现的工件有关，但是我在不同的区域用不同的四边形进行了测试——没有乐趣。