似乎无法让每个顶点数据的顶点属性数组正常工作。
这是SSCCE:
private static void createDisplay(int w, int h) {
try {
Display.create();
Display.setDisplayMode(new DisplayMode(w, h));
}
catch (LWJGLException e) {
e.printStackTrace();
}
float size = 1;
float aspect = (float) Display.getWidth() / Display.getHeight();
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(-size * aspect, size * aspect, -size, size, -1, 1);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glLoadIdentity();
}
public static void main(String[] args) {
createDisplay(1200, 800);
GL11.glViewport(0, 0, Display.getWidth(), Display.getHeight());
ShaderManager.createShader("2Dv", new File("src/Shaders/2D.vert"), SHADER_VERT);
ShaderManager.createShader("2Df", new File("src/Shaders/2D.frag"), SHADER_FRAG);
ShaderManager.createProgram("2D", "2Dv", "2Df");
// Shader compiles and links correctly.
ShaderManager.useProgram("2D");
// Calls glUseProgram(programID);
float[] vertexData = new float[] {-0.5f, -0.5f, 0.5f, -0.5f, 0.5f, 0.5f, -0.5f, 0.5f};
int vao = GL30.glGenVertexArrays();
if (vao == 0)
System.exit(-1);
GL30.glBindVertexArray(vao);
int vertexBuffer = GL15.glGenBuffers();
GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vertexBuffer);
GL15.glBufferData(GL15.GL_ARRAY_BUFFER, BufferUtil.asDirectFloatBuffer(vertexData), GL15.GL_DYNAMIC_DRAW);
// GL11.glEnableClientState(GL11.GL_VERTEX_ARRAY);
// GL11.glVertexPointer(2, GL11.GL_FLOAT, 2 * 4, 0);
int loc = ShaderManager.currentProgram.getAttribute("vertex");
if (loc == -1)
Debug.log(Debug.INSTANCE_MANAGEMENT, "Attribute [", "", "] not found in Shader [",
ShaderManager.currentProgram.toString(), "].");
else {
GL20.glVertexAttribPointer(loc, 2, GLCONST.TYPE_FLOAT, false, 2 * 4, 0);
GL20.glEnableVertexAttribArray(loc);
}
GL30.glBindVertexArray(0);
GL11.glColor3f(1, 0, 0);
GL11.glClearColor(0.5f, 0.5f, 0.8f, 1);
int indexBuffer = GL15.glGenBuffers();
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, BufferUtil.asDirectFloatBuffer(new float[] {0, 1, 2, 3}),
GL15.GL_DYNAMIC_DRAW);
while (!Display.isCloseRequested()) {
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT);
GL30.glBindVertexArray(vao);
GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
GL11.glDrawElements(GL11.GL_QUADS, 4, GL11.GL_UNSIGNED_INT, 0);
GL30.glBindVertexArray(0);
Display.update();
int error = GL11.glGetError();
if (error != GL11.GL_NO_ERROR)
System.out.println(GLU.gluErrorString(error));
}
}
问题在于顶点属性数组的使用。我使用的旧代码是:
GL11.glEnableClientState(GL11.GL_VERTEX_ARRAY);
GL11.glVertexPointer(2, GL11.GL_FLOAT, 2 * 4, 0);
新版本是:
int loc = ShaderManager.currentProgram.getAttribute("vertex");//Call to glGetAttribLocation();
if (loc == -1){
System.exit(-1);
}
GL20.glVertexAttribPointer(loc, 2, GL11.GL_FLOAT, false, 2 * 4, 0);
GL20.glEnableVertexAttribArray(loc);
原始代码是注释的 2 行。运行时,它正确地将顶点数据发送到 gl_Vertex 并渲染了一个大小为 1 的正方形。
新代码应该将顶点数据发送到顶点属性,但它什么也得不到。
当原始代码未注释并且新旧代码都使用时, gl_Vertex 和 vertex 属性都获取顶点数据。
这里出了什么问题?