[英]Trying to draw a basic shape with LWJGL3
所以我想使用VAO和VBO繪制形狀,我想我所做的一切都正確,但是每當我運行我的代碼時,我都會獲得具有清晰顏色的窗口。 在調用創建功能之前嘗試初始化三角形之前,我遇到了一個問題,我是否缺少一些開始繪制的功能?
這是我的代碼:
int vaoId, vboId, vertexCount;
float[] vertices = {
// Left bottom triangle
-0.5f, 0.5f,
-0.5f, -0.5f,
0.5f, -0.5f,};
private void init() {
if (!glfwInit()) {
throw new IllegalStateException("Failed to Initialize GLFW!");
}
int width = 1000;
int height = 1000;
glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
window = glfwCreateWindow(width, height, "App", NULL, NULL);
if (window == 0) {
throw new IllegalStateException("Failed to create Window!");
}
GLFWVidMode videoMode = glfwGetVideoMode(glfwGetPrimaryMonitor());
glfwSetWindowPos(window, (videoMode.width() - width) / 2, (videoMode.height() - height) / 2);
// Make the OpenGL context current
glfwMakeContextCurrent(window);
// Enable v-sync
glfwSwapInterval(1);
glfwShowWindow(window);
}
private void loop() {
// This line is critical for LWJGL's interoperation with GLFW's
// OpenGL context, or any context that is managed externally.
// LWJGL detects the context that is current in the current thread,
// creates the GLCapabilities instance and makes the OpenGL
// bindings available for use.
GL.createCapabilities();
initTriangle();
// Run the rendering loop until the user has attempted to close
// the window or has pressed the ESCAPE key.
while (!glfwWindowShouldClose(window)) {
glClear(GL_COLOR_BUFFER_BIT); // clear the framebuffer
glBindVertexArray(vaoId);
glEnableVertexAttribArray(0);
glDrawArrays(GL_TRIANGLES, 0, vertexCount);
glDisableVertexAttribArray(0);
glBindVertexArray(0);
glfwSwapBuffers(window); // swap the color buffers
// Poll for window events. The key callback above will only be
// invoked during this call.
glfwPollEvents();
}
}
private void initTriangle() {
FloatBuffer vertBuf = MemoryUtil.memAllocFloat(vertices.length);
vertBuf.put(vertices);
vertBuf.flip();
vaoId = glGenVertexArrays();
glBindVertexArray(vaoId);
vboId = glGenBuffers();
glBindBuffer(GL_ARRAY_BUFFER, vboId);
glBufferData(GL_ARRAY_BUFFER, vertBuf, GL_STATIC_DRAW);
glVertexAttribPointer(0, 2, GL_FLOAT, false, 0, 0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
希望你們能有所幫助,非常感謝。
我沒有使用着色器。 那是我的問題嗎? 是否有必要
OpenGL中最先進的渲染方式是使用Shader 。
如果不使用着色器,則必須通過glVertexPointer
定義頂點數據數組
vaoId = glGenVertexArrays();
glBindVertexArray(vaoId);
vboId = glGenBuffers();
glBindBuffer(GL_ARRAY_BUFFER, vboId);
glBufferData(GL_ARRAY_BUFFER, vertBuf, GL_STATIC_DRAW);
glVertexPointer( 2, GL_FLOAT, 0, 0 ); // <---------------
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
並且必須通過glEnableClientState( GL_VERTEX_ARRAY )
啟用客戶端的頂點坐標功能:
glBindVertexArray(vaoId);
glEnableClientState( GL_VERTEX_ARRAY ); // <---------------
glDrawArrays(GL_TRIANGLES, 0, vertexCount);
glDisableClientState( GL_VERTEX_ARRAY ); // <---------------
glBindVertexArray(0);
注意,客戶端功能(或頂點屬性數組)的這種狀態存儲在“ 頂點數組對象”中 。 因此,當指定頂點數組對象時,啟用頂點坐標就足夠了。 在繪制幾何圖形時,可以省略啟用和禁用頂點坐標的操作:
vaoId = glGenVertexArrays();
glBindVertexArray(vaoId);
vboId = glGenBuffers();
glBindBuffer(GL_ARRAY_BUFFER, vboId);
glBufferData(GL_ARRAY_BUFFER, vertBuf, GL_STATIC_DRAW);
glVertexPointer( 2, GL_FLOAT, 0, 0 );
glEnableClientState( GL_VERTEX_ARRAY ); // <---------------
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
glBindVertexArray(vaoId);
glDrawArrays(GL_TRIANGLES, 0, vertexCount);
glBindVertexArray(0);
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.