我正在尝试在我的程序中创建自己的顶点和片段着色器(这基本上是一个非常简单的程序,用 VBO 显示三角形)。但是,当我尝试运行它时,我总是得到一个黑屏,没有任何显示。我检查了编译日志,它返回没有错误。我还没有使用我自己的自定义着色器运行程序,这让我想知道我是否在这里做错了什么。我在 OpenGL 3.2 和 GLSL 1.5 上运行我的代码
以下是我当前尝试运行的代码
GLuint vbo;
GLfloat data[] = {0.0, 0.0, -5.0,
1.0, 0.0, -5.0,
1.0, 1.0, -5.0
};
const char *vertexShader = "\n\
#version 150\n\
\n\
layout (location=0) in vec4 position;\n\
void main()\n\
{\n\
gl_Position = position;\n\
}\n\
";
const char *fragmentShader = "\n\
#version 150\n\
\n\
out vec4 outColor;\n\
\n\
void main()\n\
{\n\
outColor = vec4(1.0, 0.0, 0.0, 1.0);\n\
}";
- (void)drawRect:(NSRect)dirtyRect
{
glClear(GL_COLOR_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glUseProgram(programId);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, 0);
glDrawArrays(GL_TRIANGLES, 0, sizeof(data));
glFlush();
glDisableClientState(GL_VERTEX_ARRAY);
}
-(void)reshape
{
glViewport(0, 0, w, h);
gluPerspective(45.0, //The camera angle
(double)w / (double)h, //The width-to-height ratio
1.0, //The near z clipping coordinate
200.0);
}
-(void)prepareOpenGL
{
glEnable(GL_DEPTH_TEST);
glGenBuffersARB(1, &vbo);
glBindBufferARB(GL_ARRAY_BUFFER_ARB, vbo);
glBufferDataARB(GL_ARRAY_BUFFER_ARB, sizeof(data), data, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, 0, 0, 0);
vertexShaderId = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShaderId, 1, &vertexShader, NULL);
glCompileShader(vertexShaderId);
GLint completed;
glGetShaderiv(vertexShaderId, GL_COMPILE_STATUS, &completed);
if (!completed)
{
GLint length;
GLchar *log;
glGetShaderiv(vertexShaderId, GL_INFO_LOG_LENGTH, &length);
log = (GLchar *)malloc(length);
glGetShaderInfoLog(vertexShaderId, length, &length, log);
fprintf(stderr, "Vertex compile log = '%s'\n", log);
}
fragmentShaderId = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShaderId, 1, &fragmentShader, NULL);
glCompileShader(fragmentShaderId);
GLint complete;
glGetShaderiv(fragmentShaderId, GL_COMPILE_STATUS, &complete);
if (!complete)
{
GLint length;
GLchar *log;
glGetShaderiv(fragmentShaderId, GL_INFO_LOG_LENGTH, &length);
log = (GLchar *)malloc(length);
glGetShaderInfoLog(fragmentShaderId, length, &length, log);
fprintf(stderr, "fragment compile log = '%s'\n", log);
}
programId = glCreateProgram();
glAttachShader(programId, vertexShaderId);
glAttachShader(programId, fragmentShaderId);
glLinkProgram(programId);
glUseProgram(programId);
}