Add GlRect helper class

Adds a class that represents an image rectangle
in OpenGL coordinate convention.

android.graphics.Rect puts (0, 0) as the top-left corner:
it enforces `Rect.top <= Rect.bottom` and this matches
`android.graphics.Bitmap` coordinates: docs https://developer.android.com/reference/android/graphics/Rect

This is different from OpenGL coordinates where (0, 0) is
at the bottom-left corner. I.e. GlRect.bottom <= GlRect.top: docs https://registry.khronos.org/OpenGL-Refpages/es3.0/html/glReadPixels.xhtml

The reason for this change is to allow a public API GlRect
getScaledRegion() which selects a region of pixels of a GL texture
to be copied to CPU memory.

PiperOrigin-RevId: 669231826

libraries/common/src/main/java/androidx/media3/common/util/GlRect.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package androidx.media3.common.util;
+
+import static androidx.media3.common.util.Assertions.checkArgument;
+
+/**
+ * Represents a rectangle by the coordinates of its 4 edges (left, bottom, right, top).
+ *
+ * <p>Note that the right and top coordinates are exclusive.
+ *
+ * <p>This class represents coordinates in the OpenGL coordinate convention: {@code left <= right}
+ * and {@code bottom <= top}.
+ */
+@UnstableApi
+public final class GlRect {
+  public int left;
+  public int bottom;
+  public int right;
+  public int top;
+
+  /** Creates an instance from (0, 0) to the specified width and height. */
+  public GlRect(int width, int height) {
+    this(/* left= */ 0, /* bottom= */ 0, width, height);
+  }
+
+  /** Creates an instance. */
+  public GlRect(int left, int bottom, int right, int top) {
+    checkArgument(left <= right && bottom <= top);
+    this.left = left;
+    this.bottom = bottom;
+    this.right = right;
+    this.top = top;
+  }
+}

libraries/common/src/main/java/androidx/media3/common/util/GlUtil.java

@@ -23,7 +23,6 @@ import static androidx.media3.common.util.Assertions.checkState;
 import android.content.Context;
 import android.content.pm.PackageManager;
 import android.graphics.Bitmap;
-import android.graphics.Rect;
 import android.opengl.EGL14;
 import android.opengl.EGLConfig;
 import android.opengl.EGLContext;
@@ -837,7 +836,7 @@ public final class GlUtil {
    * @param drawFboId The framebuffer object to draw into.
    * @param drawRect The rectangular region of {@code drawFboId} to draw into.
    */
-  public static void blitFrameBuffer(int readFboId, Rect readRect, int drawFboId, Rect drawRect)
+  public static void blitFrameBuffer(int readFboId, GlRect readRect, int drawFboId, GlRect drawRect)
       throws GlException {
     int[] boundFramebuffer = new int[1];
     GLES20.glGetIntegerv(GLES20.GL_FRAMEBUFFER_BINDING, boundFramebuffer, /* offset= */ 0);
@@ -848,13 +847,13 @@ public final class GlUtil {
     checkGlError();
     GLES30.glBlitFramebuffer(
         readRect.left,
-        readRect.top,
-        readRect.right,
         readRect.bottom,
+        readRect.right,
+        readRect.top,
         drawRect.left,
-        drawRect.top,
-        drawRect.right,
         drawRect.bottom,
+        drawRect.right,
+        drawRect.top,
         GLES30.GL_COLOR_BUFFER_BIT,
         GLES30.GL_LINEAR);
     checkGlError();

libraries/effect/src/androidTest/java/androidx/media3/effect/ByteBufferGlEffectTest.java

@@ -26,7 +26,6 @@ import static com.google.common.truth.Truth.assertThat;
 
 import android.graphics.Bitmap;
 import android.graphics.Color;
-import android.graphics.Rect;
 import android.text.Spannable;
 import android.text.SpannableString;
 import android.text.style.AbsoluteSizeSpan;
@@ -34,6 +33,7 @@ import android.text.style.ForegroundColorSpan;
 import android.text.style.TypefaceSpan;
 import androidx.media3.common.GlTextureInfo;
 import androidx.media3.common.util.Consumer;
+import androidx.media3.common.util.GlRect;
 import androidx.media3.common.util.Size;
 import androidx.media3.common.util.Util;
 import androidx.media3.test.utils.TextureBitmapReader;
@@ -140,12 +140,8 @@ public class ByteBufferGlEffectTest {
     }
 
     @Override
-    public Rect getScaledRegion(long presentationTimeUs) {
+    public GlRect getScaledRegion(long presentationTimeUs) {
-      return new Rect(
+      return new GlRect(INPUT_FRAME_WIDTH, INPUT_FRAME_HEIGHT);
-          /* left= */ 0,
-          /* top= */ 0,
-          /* right= */ INPUT_FRAME_WIDTH,
-          /* bottom= */ INPUT_FRAME_HEIGHT);
     }
 
     @Override

libraries/effect/src/main/java/androidx/media3/effect/ByteBufferConcurrentEffect.java

@@ -19,11 +19,11 @@ import static androidx.media3.common.util.Assertions.checkNotNull;
 import static androidx.media3.common.util.Assertions.checkState;
 import static com.google.common.util.concurrent.Futures.immediateFailedFuture;
 
-import android.graphics.Rect;
 import androidx.media3.common.C;
 import androidx.media3.common.GlObjectsProvider;
 import androidx.media3.common.GlTextureInfo;
 import androidx.media3.common.VideoFrameProcessingException;
+import androidx.media3.common.util.GlRect;
 import androidx.media3.common.util.GlUtil;
 import androidx.media3.common.util.Size;
 import androidx.media3.common.util.Util;
@@ -107,8 +107,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
           textureInfo.fboId,
           processor.getScaledRegion(presentationTimeUs),
           effectInputTexture.fboId,
-          new Rect(
+          new GlRect(effectInputTexture.width, effectInputTexture.height));
-              /* left= */ 0, /* top= */ 0, effectInputTexture.width, effectInputTexture.height));
 
       TexturePixelBuffer texturePixelBuffer = new TexturePixelBuffer(effectInputTexture);
       unmappedPixelBuffers.add(texturePixelBuffer);

libraries/effect/src/main/java/androidx/media3/effect/ByteBufferGlEffect.java

@@ -20,10 +20,10 @@ import static androidx.media3.common.util.Assertions.checkArgument;
 import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.Matrix;
-import android.graphics.Rect;
 import android.opengl.GLES20;
 import androidx.media3.common.GlTextureInfo;
 import androidx.media3.common.VideoFrameProcessingException;
+import androidx.media3.common.util.GlRect;
 import androidx.media3.common.util.Size;
 import androidx.media3.common.util.UnstableApi;
 import com.google.common.util.concurrent.ListenableFuture;
@@ -143,9 +143,7 @@ import java.util.concurrent.Future;
      * @return The rectangular region of the input image that will be scaled to fill the effect
      *     input image.
      */
-    // TODO: b/b/361286064 - This method misuses android.graphics.Rect for OpenGL coordinates.
+    GlRect getScaledRegion(long presentationTimeUs);
-    //   Implement a custom GlUtils.Rect to correctly label lower left corner as (0, 0).
-    Rect getScaledRegion(long presentationTimeUs);
 
     /**
      * Processing the image data in the {@code image}.

libraries/effect/src/main/java/androidx/media3/effect/QueuingGlShaderProgram.java

@@ -18,13 +18,13 @@ package androidx.media3.effect;
 import static androidx.media3.common.util.Assertions.checkArgument;
 import static androidx.media3.common.util.Assertions.checkState;
 
-import android.graphics.Rect;
 import androidx.annotation.CallSuper;
 import androidx.annotation.IntRange;
 import androidx.media3.common.C;
 import androidx.media3.common.GlObjectsProvider;
 import androidx.media3.common.GlTextureInfo;
 import androidx.media3.common.VideoFrameProcessingException;
+import androidx.media3.common.util.GlRect;
 import androidx.media3.common.util.GlUtil;
 import androidx.media3.common.util.UnstableApi;
 import com.google.common.util.concurrent.Futures;
@@ -213,10 +213,9 @@ import java.util.concurrent.TimeUnit;
       checkState(inputTexture.fboId != C.INDEX_UNSET);
       GlUtil.blitFrameBuffer(
           inputTexture.fboId,
-          new Rect(/* left= */ 0, /* top= */ 0, /* right= */ inputWidth, /* bottom= */ inputHeight),
+          new GlRect(inputWidth, inputHeight),
           outputTexture.fboId,
-          new Rect(
+          new GlRect(inputWidth, inputHeight));
-              /* left= */ 0, /* top= */ 0, /* right= */ inputWidth, /* bottom= */ inputHeight));
 
       Future<T> task =
           concurrentEffect.queueInputFrame(glObjectsProvider, outputTexture, presentationTimeUs);