8266079: Lanai: AlphaComposite shows differences on Metal compared to OpenGL

src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/MTLLayer.m

@@ -113,7 +113,8 @@ - (void) blitTexture {
             return;
         }
         self.nextDrawableCount++;
-
+//#define MTL_LAYER_USE_BLIT_ENC
+#ifdef MTL_LAYER_USE_BLIT_ENC
         id <MTLBlitCommandEncoder> blitEncoder = [commandBuf blitCommandEncoder];
 
         [blitEncoder
@@ -122,7 +123,40 @@ - (void) blitTexture {
                 sourceSize:MTLSizeMake(src_w, src_h, 1)
                 toTexture:mtlDrawable.texture destinationSlice:0 destinationLevel:0 destinationOrigin:MTLOriginMake(0, 0, 0)];
         [blitEncoder endEncoding];
+#else
+        id<MTLCommandBuffer> cb = [ctx createCommandBuffer];
+        id<MTLComputeCommandEncoder> computeEncoder = [cb computeCommandEncoder];
+        id<MTLComputePipelineState> computePipelineState = [ctx.pipelineStateStorage
+                                                            getComputePipelineState:@"tex2tex_opaque"];
+        [computeEncoder setComputePipelineState:computePipelineState];
+
+        NSUInteger maxTotalThreadsPerThreadgroup = computePipelineState.maxTotalThreadsPerThreadgroup;
+        NSUInteger w = computePipelineState.threadExecutionWidth;
+
+        // Workaround for some OS/device bug reporting incorrect maxTotalThreadsPerThreadgroup
+        if (maxTotalThreadsPerThreadgroup == 0) {
+            maxTotalThreadsPerThreadgroup = 1;
+            w = 1;
+        }
+
+        NSUInteger h = maxTotalThreadsPerThreadgroup / w;
+        MTLSize threadgroupSize = MTLSizeMake(w, h, 1);
+        MTLSize threadgroupCount;
+
+        threadgroupCount.width  = (buffer.width - src_x + threadgroupSize.width - 1) / threadgroupSize.width;
+        threadgroupCount.height = (buffer.height - src_y + threadgroupSize.height - 1) / threadgroupSize.height;
+        threadgroupCount.depth = 1;
+
+        [computeEncoder setTexture:buffer atIndex:0];
+        [computeEncoder setTexture:mtlDrawable.texture atIndex:1];
+        struct InsetsUniforms uniforms = {src_x, src_y};
+        [computeEncoder setBytes:&uniforms length:sizeof(struct InsetsUniforms) atIndex:2];
 
+        [computeEncoder dispatchThreadgroups:threadgroupCount
+                               threadsPerThreadgroup:threadgroupSize];
+        [computeEncoder endEncoding];
+        [cb commit];
+#endif
         [commandBuf presentDrawable:mtlDrawable];
         [commandBuf addCompletedHandler:^(id <MTLCommandBuffer> commandBuf) {
             self.nextDrawableCount--;

src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/common.h

@@ -161,4 +161,10 @@ struct SwizzleUniforms {
     unsigned char swizzle[4];
     unsigned char hasAlpha;
 };
+
+struct InsetsUniforms {
+    int left;
+    int top;
+};
+
 #endif

src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/shaders.metal

@@ -643,6 +643,16 @@ kernel void stencil2tex(const device uchar *imageBuffer [[buffer(0)]],
     outputBuffer[gid] = uchar4(p, p, p, p);
 }
 
+kernel void tex2tex_opaque(texture2d<half, access::read> inTexture [[texture(0)]],
+    texture2d<half, access::write> outTexture [[texture(1)]],
+    constant InsetsUniforms& uniforms [[buffer(2)]],
+    uint2 gid [[thread_position_in_grid]])
+{
+    half4 inColor  = inTexture.read(uint2(gid[0] + uniforms.left, gid[1] + uniforms.top));
+    half4 outColor = half4(inColor.rgb, 1.0);
+    outTexture.write(outColor, gid);
+}
+
 // work item deals with 4 byte pixel
 // assuming that data is aligned
 kernel void swizzle_to_rgba(const device uchar *imageBuffer [[buffer(0)]],

test/jdk/java/awt/AlphaComposite/WindowAlphaCompositeTest.java

@@ -0,0 +1,238 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, JetBrains s.r.o.. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @key headful
+ * @bug 8266079
+ * @summary [macosx] window rendering alpha composite test
+ * @author Alexey Ushakov
+ * @run main WindowAlphaCompositeTest
+ * @requires (os.family == "mac")
+ */
+
+import java.awt.*;
+import java.awt.image.BufferedImage;
+import java.lang.reflect.InvocationTargetException;
+import javax.swing.*;
+
+public class WindowAlphaCompositeTest
+{
+    interface Validate {
+        boolean validate(int x, int y, Color c);
+    }
+    static Color RED128 = new Color(128, 0, 0);
+    static Color BLUE128 = new Color(0, 0, 128);
+    static Color PURPLE128 = new Color(128, 0, 128);
+    static Color RED_BLUE24 = new Color(230, 0, 24);
+    static Validate redBlackCheck = (int x, int y, Color c) -> {
+        Color expColor = Color.RED;
+        if (x > 24 && x < 75) {
+            expColor = Color.BLACK;
+        }
+        return validateColor(c, expColor);
+    };
+
+    static Validate redBlueCheck = (int x, int y, Color c) -> {
+        Color expColor = Color.RED;
+        if (x > 24 && x < 75) {
+            expColor = Color.BLUE;
+        }
+        return validateColor(c, expColor);
+    };
+
+    static Validate redCheck = (int x, int y, Color c) -> {
+        Color expColor = Color.RED;
+        return validateColor(c, expColor);
+    };
+
+    static Validate redRed128Check = (int x, int y, Color c) -> {
+        Color expColor = Color.RED;
+        if (x > 24 && x < 75) {
+            expColor = RED128;
+        }
+        return validateColor(c, expColor);
+    };
+
+    static Validate redBlue128Check = (int x, int y, Color c) -> {
+        Color expColor = Color.RED;
+        if (x > 24 && x < 75) {
+            expColor = BLUE128;
+        }
+        return validateColor(c, expColor);
+    };
+
+    static Validate purple128Check = (int x, int y, Color c) -> {
+        Color expColor = Color.RED;
+        if (x > 24 && x < 75) {
+            expColor = PURPLE128;
+        }
+        return validateColor(c, expColor);
+    };
+    static Validate redBlue24Check = (int x, int y, Color c) -> {
+        Color expColor = Color.RED;
+        if (x > 24 && x < 75) {
+            expColor = RED_BLUE24;
+        }
+        return validateColor(c, expColor);
+    };
+    static Object[][] alphaComposites = {
+            {AlphaComposite.Clear, redBlackCheck},
+            {AlphaComposite.Dst, redCheck},
+            {AlphaComposite.DstAtop, redCheck},
+            {AlphaComposite.getInstance(AlphaComposite.DST_IN, 1.0f), redCheck},
+            {AlphaComposite.getInstance(AlphaComposite.DST_IN, 0.5f), redRed128Check},
+            {AlphaComposite.getInstance(AlphaComposite.DST_OUT, 1.0f), redBlackCheck},
+            {AlphaComposite.getInstance(AlphaComposite.DST_OUT, 0.5f), redRed128Check},
+            {AlphaComposite.DstOver, redCheck},
+            {AlphaComposite.Src, redBlueCheck},
+            {AlphaComposite.SrcAtop, redBlueCheck},
+            {AlphaComposite.getInstance(AlphaComposite.SRC_IN, 1.0f), redBlueCheck},
+            {AlphaComposite.getInstance(AlphaComposite.SRC_IN, 0.5f), redBlue128Check},
+            {AlphaComposite.SrcOut, redBlackCheck},
+            {AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 1.0f), redBlueCheck},
+            {AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f), purple128Check},
+            //Uncomment after resolving issues with Xor mode on Metal
+            //{AlphaComposite.Xor, redBlackCheck},
+            {AlphaComposite.getInstance(AlphaComposite.DST_OUT, 0.0f), redCheck},
+            {AlphaComposite.getInstance(AlphaComposite.SRC_IN, 0.0f), redBlackCheck},
+            {AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.01f), redCheck},
+            {AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.099f), redBlue24Check}
+    };
+
+    private static final int TD = 10;
+    static WindowAlphaCompositeTest theTest;
+    private final Robot robot;
+    private JFrame frame;
+
+    private final static int DELAY = 1000;
+
+    public WindowAlphaCompositeTest() {
+        try {
+            robot = new Robot();
+        } catch (AWTException ex) {
+            throw new RuntimeException(ex);
+        }
+    }
+
+    public void performTest(final AlphaComposite ac, Validate validate) {
+
+        runSwing(() -> {
+            frame = new JFrame();
+            frame.setBounds(100, 100, 100, 150);
+            JComponent contentPane = (JComponent) frame.getContentPane();
+            JPanel comp = new JPanel() {
+                @Override
+                protected void paintComponent(Graphics g) {
+                    super.paintComponent(g);
+                    renderComposite((Graphics2D) g, ac, 100, 100);
+                }
+            };
+            contentPane.add(comp);
+            comp.setBackground(Color.BLACK);
+            frame.setVisible(true);
+        });
+
+        robot.delay(DELAY);
+
+        for (int px = 10; px <= 90; px += 20) {
+            Color c = getTestPixel(px, 90);
+
+            if (!validate.validate(px, 90, c)) {
+                throw new RuntimeException("Test failed. Incorrect color " + c +
+                        " at (" + px + "," + 90 + ") with composite rule=" + ac.getRule() +
+                        " alpha=" + ac.getAlpha());
+            }
+        }
+
+        runSwing(() -> frame.dispose());
+
+        frame = null;
+    }
+
+    public void renderComposite(Graphics2D g, AlphaComposite ac,
+                                int w, int h)
+    {
+        // draw stage
+        // outer rect
+        g.setComposite(AlphaComposite.SrcOver); // as default
+        g.setPaint(Color.red);
+        g.fillRect(0, 0, w, h);
+
+        // inner rect
+        g.setComposite(ac);
+        g.setPaint(Color.blue);
+        g.fillRect(w/4, h/4, w/2, h/2);
+    }
+
+    private Color getTestPixel(int x, int y) {
+        Rectangle bounds = frame.getBounds();
+        BufferedImage screenImage = robot.createScreenCapture(bounds);
+        int rgb = screenImage.getRGB(x, y);
+        int red = (rgb >> 16) & 0xFF;
+        int green = (rgb >> 8) & 0xFF;
+        int blue = rgb & 0xFF;
+        return new Color(red, green, blue);
+    }
+
+    private static boolean validateColor(Color c, Color expected) {
+        return Math.abs(c.getRed() - expected.getRed()) <= TD &&
+            Math.abs(c.getGreen() - expected.getGreen()) <= TD &&
+            Math.abs(c.getBlue() - expected.getBlue()) <= TD;
+    }
+
+    public void dispose() {
+        if (frame != null) {
+            frame.dispose();
+            frame = null;
+        }
+    }
+
+    private static void runSwing(Runnable r) {
+        try {
+            SwingUtilities.invokeAndWait(r);
+        } catch (InterruptedException | InvocationTargetException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static void main(String[] args) {
+        if (!System.getProperty("os.name").contains("OS X")) {
+            System.out.println("This test is for MacOS only. Automatically passed on other platforms.");
+            return;
+        }
+
+        try {
+            for (Object[] alphaComposite : alphaComposites) {
+                if (alphaComposite[1] == null) continue;
+                runSwing(() -> theTest = new WindowAlphaCompositeTest());
+                theTest.performTest((AlphaComposite) alphaComposite[0], (Validate) alphaComposite[1]);
+            }
+        } finally {
+            if (theTest != null) {
+                runSwing(() -> theTest.dispose());
+            }
+        }
+    }
+}