Java LWJGL OpenGL 3 将 3d 点转换为 2d 点
Java LWJGL OpenGL 3 convert 3d point to 2d point
我正在尝试在 LWJGL 3 中将 3d 矢量转换为 2d 矢量。
目标是在 3d 世界中移动时在 2d 屏幕上呈现名称标签。
这是我在 LWJGL 2 上使用的:
public static Vector2d to2D(double x, double y, double z) {
FloatBuffer screenCoords = BufferUtils.createFloatBuffer(3);
IntBuffer viewport = BufferUtils.createIntBuffer(16);
FloatBuffer modelView = BufferUtils.createFloatBuffer(16);
FloatBuffer projection = BufferUtils.createFloatBuffer(16);
GL11.glGetFloat(GL11.GL_MODELVIEW_MATRIX, modelView);
GL11.glGetFloat(GL11.GL_PROJECTION_MATRIX, projection);
GL11.glGetInteger(GL11.GL_VIEWPORT, viewport);
boolean result = GLU.gluProject((float) x, (float) y, (float) z, modelView, projection, viewport, screenCoords);
if (result) {
return new Vector2d(screenCoords.get(0), Display.getHeight() - screenCoords.get(1));
}
return null;
}
在 LWJGL 2 中,使用 GLU.gluProject() 是可行的,现在已删除,在新的 LWJGL 版本中是否有任何替代方案?
您可以使用 JOML (which is also downloadable as an LWJGL 3 Addon) and its Matrix4f.project()
方法。以下是您为 LWJGL3 + JOML 显示的代码片段的功能端口:
import java.nio.*;
import org.joml.*;
import org.lwjgl.opengl.GL11;
import org.lwjgl.system.MemoryStack;
public class Snippet {
public static Vector2d to2D(double x, double y, double z, int displayHeight) {
Vector3f screenCoords = new Vector3f();
int[] viewport = new int[4];
try (MemoryStack stack = MemoryStack.stackPush()) {
FloatBuffer modelView = stack.mallocFloat(16);
FloatBuffer projection = stack.mallocFloat(16);
GL11.glGetFloatv(GL11.GL_MODELVIEW_MATRIX, modelView);
GL11.glGetFloatv(GL11.GL_PROJECTION_MATRIX, projection);
GL11.glGetIntegerv(GL11.GL_VIEWPORT, viewport);
new Matrix4f(projection)
.mul(new Matrix4f(modelView))
.project((float) x, (float) y, (float) z, viewport, screenCoords);
}
return new Vector2d(screenCoords.x, displayHeight - screenCoords.y);
}
}
除了端口之外,我还遵循了 LWJGL 3 中有关本机内存管理的最佳实践:https://blog.lwjgl.org/memory-management-in-lwjgl-3/#strategy5
我正在尝试在 LWJGL 3 中将 3d 矢量转换为 2d 矢量。 目标是在 3d 世界中移动时在 2d 屏幕上呈现名称标签。
这是我在 LWJGL 2 上使用的:
public static Vector2d to2D(double x, double y, double z) {
FloatBuffer screenCoords = BufferUtils.createFloatBuffer(3);
IntBuffer viewport = BufferUtils.createIntBuffer(16);
FloatBuffer modelView = BufferUtils.createFloatBuffer(16);
FloatBuffer projection = BufferUtils.createFloatBuffer(16);
GL11.glGetFloat(GL11.GL_MODELVIEW_MATRIX, modelView);
GL11.glGetFloat(GL11.GL_PROJECTION_MATRIX, projection);
GL11.glGetInteger(GL11.GL_VIEWPORT, viewport);
boolean result = GLU.gluProject((float) x, (float) y, (float) z, modelView, projection, viewport, screenCoords);
if (result) {
return new Vector2d(screenCoords.get(0), Display.getHeight() - screenCoords.get(1));
}
return null;
}
在 LWJGL 2 中,使用 GLU.gluProject() 是可行的,现在已删除,在新的 LWJGL 版本中是否有任何替代方案?
您可以使用 JOML (which is also downloadable as an LWJGL 3 Addon) and its Matrix4f.project()
方法。以下是您为 LWJGL3 + JOML 显示的代码片段的功能端口:
import java.nio.*;
import org.joml.*;
import org.lwjgl.opengl.GL11;
import org.lwjgl.system.MemoryStack;
public class Snippet {
public static Vector2d to2D(double x, double y, double z, int displayHeight) {
Vector3f screenCoords = new Vector3f();
int[] viewport = new int[4];
try (MemoryStack stack = MemoryStack.stackPush()) {
FloatBuffer modelView = stack.mallocFloat(16);
FloatBuffer projection = stack.mallocFloat(16);
GL11.glGetFloatv(GL11.GL_MODELVIEW_MATRIX, modelView);
GL11.glGetFloatv(GL11.GL_PROJECTION_MATRIX, projection);
GL11.glGetIntegerv(GL11.GL_VIEWPORT, viewport);
new Matrix4f(projection)
.mul(new Matrix4f(modelView))
.project((float) x, (float) y, (float) z, viewport, screenCoords);
}
return new Vector2d(screenCoords.x, displayHeight - screenCoords.y);
}
}
除了端口之外,我还遵循了 LWJGL 3 中有关本机内存管理的最佳实践:https://blog.lwjgl.org/memory-management-in-lwjgl-3/#strategy5