OpenGL ES 2.0 GLKit画一条线

Question

我试图用OpenGL ES 2.0 GLKit绘制一条线.当我运行以下代码并使用OpenGL ES Analyzer时,我收到以下错误:

"使用不存在的程序"glDrawArrays(GL_LINE_STRIP,0,4)

"GL错误:无效操作"GL_INVALID_OPERATION < - glVertexPointer(2,GL_FLOAT,0,NULL)GL_INVALID_OPERATION < - glEnableClientState(GL_VERTEX_ARRAY)

这是我的代码:

#import "GLDrawingView.h"


const float data[] = {0.0f, 1.0f, 0.0f, 0.0f, 1.0f, -0.0f, 0.0f, 1.0f};



@interface GLDrawingView () {
    GLuint lineVBO;
}

@end

@implementation GLDrawingView

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [EAGLContext setCurrentContext:self.context];           
        glGenBuffers(1, &lineVBO);
        glBindBuffer(GL_ARRAY_BUFFER, lineVBO);
        glBufferData(GL_ARRAY_BUFFER, sizeof(data), data, GL_STATIC_DRAW);
    }
    return self;
}

- (void)drawRect:(CGRect)rect
{
    glVertexPointer(2, GL_FLOAT, 0, NULL);   
    glEnableClientState(GL_VERTEX_ARRAY);
    glDrawArrays(GL_LINE_STRIP, 0, sizeof(data) / sizeof(float) / 2);
}

@end

Answer 1

在OpenGL ES 2.0中绘制内容时,必须使用着色器程序(glUseProgram)进行渲染.在GLES2中无法使用着色器进行渲染.