直接上代码。
import com.mojang.blaze3d.systems.RenderSystem;
import com.mojang.blaze3d.vertex.*;
import net.minecraft.client.Minecraft;
import net.minecraft.client.gui.GuiGraphics;
import net.minecraft.client.gui.screens.Screen;
import net.minecraft.client.renderer.GameRenderer;
import net.minecraft.network.chat.Component;
import net.minecraft.util.FastColor;
import org.joml.Matrix4f;
import org.lwjgl.BufferUtils;
import org.lwjgl.opengl.GL11;
import java.awt.*;
import java.nio.ByteBuffer;
public class ColorPickerScreen extends Screen {
private int pickColor = 0xFFFFFFFF;
private int hueColor = Color.HSBtoRGB(0f, 1f, 1f);
private double pendingMouseX = -1, pendingMouseY = -1;
// 色板与色相条的位置/尺寸常量
private static final int PANEL_X = 0, PANEL_Y = 0, PANEL_W = 200, PANEL_H = 100;
private static final int HUE_X = 10, HUE_H = 20, HUE_W = 200, HUE_Y_OFFSET = 30;
private static final int PREVIEW_X = 300, PREVIEW_Y = 0, PREVIEW_W = 50, PREVIEW_H = 50;
private static final int HUE_SEGMENTS = 100;
public ColorPickerScreen() {
super(Component.literal("HSV Color Picker"));
}
Override
public void render {
super.render(guiGraphics, mouseX, mouseY, partialTicks);
Matrix4f mat = guiGraphics.pose().last().pose();
Tesselator tess = Tesselator.getInstance();
BufferBuilder buf = tess.getBuilder();
RenderSystem.setShader(GameRenderer::getPositionColorShader);
buf.begin(VertexFormat.Mode.QUADS, DefaultVertexFormat.POSITION_COLOR);
drawColorPanel(mat, buf);
drawHueBar(mat, buf);
drawPreview(mat, buf);
tess.end();
// 在所有内容绘制完后再执行拾色
handlePendingPick(guiGraphics);
}
Override
public boolean mouseClicked {
this.pendingMouseX = mouseX;
this.pendingMouseY = mouseY;
return super.mouseClicked(mouseX, mouseY, button);
}
// === 私有封装方法 ===
/** 绘制从黑→黑→选中色→白的渐变色板 */
private void drawColorPanel(Matrix4f mat, BufferBuilder buf) {
buf.vertex(mat, PANEL_X, PANEL_Y + PANEL_H, 0).color(0f, 0f, 0f, 1f).endVertex();
buf.vertex(mat, PANEL_X + PANEL_W, PANEL_Y + PANEL_H, 0).color(0f, 0f, 0f, 1f).endVertex();
float rHue = FastColor.ARGB32.red(hueColor) / 255f;
float gHue = FastColor.ARGB32.green(hueColor) / 255f;
float bHue = FastColor.ARGB32.blue(hueColor) / 255f;
buf.vertex(mat, PANEL_X + PANEL_W, PANEL_Y, 0).color(rHue, gHue, bHue, 1f).endVertex();
buf.vertex(mat, PANEL_X, PANEL_Y, 0).color(1f, 1f, 1f, 1f).endVertex();
}
/** 绘制水平色相条 */
private void drawHueBar(Matrix4f mat, BufferBuilder buf) {
int hueY = this.height - HUE_Y_OFFSET;
for (int i = 0; i < HUE_SEGMENTS; i++) {
float h1 = (float) i / HUE_SEGMENTS;
float h2 = (float)(i + 1) / HUE_SEGMENTS;
int c1 = Color.HSBtoRGB(h1, 1f, 1f);
int c2 = Color.HSBtoRGB(h2, 1f, 1f);
float r1 = ((c1>>16)&0xFF)/255f, g1 = ((c1>>8)&0xFF)/255f, b1 = (c1&0xFF)/255f;
float r2 = ((c2>>16)&0xFF)/255f, g2 = ((c2>>8)&0xFF)/255f, b2 = (c2&0xFF)/255f;
int x1 = HUE_X + i * HUE_W / HUE_SEGMENTS;
int x2 = HUE_X + (i+1) * HUE_W / HUE_SEGMENTS;
buf.vertex(mat, x1, hueY, 0).color(r1, g1, b1, 1f).endVertex();
buf.vertex(mat, x2, hueY, 0).color(r2, g2, b2, 1f).endVertex();
buf.vertex(mat, x2, hueY + HUE_H, 0).color(r2, g2, b2, 1f).endVertex();
buf.vertex(mat, x1, hueY + HUE_H, 0).color(r1, g1, b1, 1f).endVertex();
}
}
/** 在右侧绘制当前 pickColor 预览小矩形 */
private void drawPreview(Matrix4f mat, BufferBuilder buf) {
float r = FastColor.ARGB32.red(pickColor) / 255f;
float g = FastColor.ARGB32.green(pickColor) / 255f;
float b = FastColor.ARGB32.blue(pickColor) / 255f;
buf.vertex(mat, PREVIEW_X, PREVIEW_Y + PREVIEW_H, 0).color(r, g, b, 1f).endVertex();
buf.vertex(mat, PREVIEW_X + PREVIEW_W, PREVIEW_Y + PREVIEW_H, 0).color(r, g, b, 1f).endVertex();
buf.vertex(mat, PREVIEW_X + PREVIEW_W, PREVIEW_Y, 0).color(r, g, b, 1f).endVertex();
buf.vertex(mat, PREVIEW_X, PREVIEW_Y, 0).color(r, g, b, 1f).endVertex();
}
/** 处理 pendingMouseX/Y，进行边界检查并调用 glReadPixels 拾色 */
private void handlePendingPick(GuiGraphics guiGraphics) {
if (pendingMouseX < 0) return;
// 边界判断：面板 或 色相条
boolean inPanel = pendingMouseX >= PANEL_X && pendingMouseX <= PANEL_X + PANEL_W
&& pendingMouseY >= PANEL_Y && pendingMouseY <= PANEL_Y + PANEL_H;
int hueY = this.height - HUE_Y_OFFSET;
boolean inHue = pendingMouseX >= HUE_X && pendingMouseX <= HUE_X + HUE_W
&& pendingMouseY >= hueY && pendingMouseY <= hueY + HUE_H;
if (!inPanel && !inHue) {
pendingMouseX = pendingMouseY = -1;
return;
}
// 计算 OpenGL 像素坐标
double scale = Minecraft.getInstance().getWindow().getGuiScale();
if (scale < 1) scale = 1;
int px = (int)(pendingMouseX * scale);
int py = (int)(pendingMouseY * scale);
int glY = Minecraft.getInstance().getWindow().getHeight() - py - 1;
guiGraphics.flush();
ByteBuffer buf = BufferUtils.createByteBuffer(3);
GL11.glReadPixels(px, glY, 1, 1, GL11.GL_RGB, GL11.GL_UNSIGNED_BYTE, buf);
int r = buf.get(0)&0xFF, g = buf.get(1)&0xFF, b = buf.get(2)&0xFF;
if (inHue) {
hueColor = FastColor.ARGB32.color(255, r, g, b);
} else {
pickColor = FastColor.ARGB32.color(255, r, g, b);
}
pendingMouseX = pendingMouseY = -1;
}
}
具体的注释都在代码里面了，一些魔法数字我也写成了字段。
项目地址在我的github仓库， 都是LGPLv3的代码
