Fix GlUtil vector size constant name.

This constant is used for https://docs.gl/es2/glVertexAttribPointer
which takes the number of components per generic vertex attribute
(meaning the size of the individual coordinate vectors here) not the
number of attributes (the number of vertices that the old constant
name referred to).

PiperOrigin-RevId: 447427241

demos/gl/src/main/java/com/google/android/exoplayer2/gldemo/BitmapOverlayVideoProcessor.java

@@ -87,9 +87,13 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
       throw new IllegalStateException(e);
     }
     program.setBufferAttribute(
-        "aFramePosition", GlUtil.getNormalizedCoordinateBounds(), GlUtil.RECTANGLE_VERTICES_COUNT);
+        "aFramePosition",
+        GlUtil.getNormalizedCoordinateBounds(),
+        GlUtil.HOMOGENEOUS_COORDINATE_VECTOR_SIZE);
     program.setBufferAttribute(
-        "aTexCoords", GlUtil.getTextureCoordinateBounds(), GlUtil.RECTANGLE_VERTICES_COUNT);
+        "aTexCoords",
+        GlUtil.getTextureCoordinateBounds(),
+        GlUtil.HOMOGENEOUS_COORDINATE_VECTOR_SIZE);
     GLES20.glGenTextures(1, textures, 0);
     GLES20.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
     GLES20.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);

demos/transformer/src/main/java/com/google/android/exoplayer2/transformerdemo/BitmapOverlayFrameProcessor.java

@@ -101,7 +101,9 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     glProgram = new GlProgram(context, VERTEX_SHADER_PATH, FRAGMENT_SHADER_PATH);
     // Draw the frame on the entire normalized device coordinate space, from -1 to 1, for x and y.
     glProgram.setBufferAttribute(
-        "aFramePosition", GlUtil.getNormalizedCoordinateBounds(), GlUtil.RECTANGLE_VERTICES_COUNT);
+        "aFramePosition",
+        GlUtil.getNormalizedCoordinateBounds(),
+        GlUtil.HOMOGENEOUS_COORDINATE_VECTOR_SIZE);
     glProgram.setSamplerTexIdUniform("uTexSampler0", inputTexId, /* texUnitIndex= */ 0);
     glProgram.setSamplerTexIdUniform("uTexSampler1", bitmapTexId, /* texUnitIndex= */ 1);
     glProgram.setFloatUniform("uScaleX", bitmapScaleX);

demos/transformer/src/main/java/com/google/android/exoplayer2/transformerdemo/PeriodicVignetteFrameProcessor.java

@@ -87,7 +87,9 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     glProgram.setFloatsUniform("uOuterRadius", new float[] {outerRadius});
     // Draw the frame on the entire normalized device coordinate space, from -1 to 1, for x and y.
     glProgram.setBufferAttribute(
-        "aFramePosition", GlUtil.getNormalizedCoordinateBounds(), GlUtil.RECTANGLE_VERTICES_COUNT);
+        "aFramePosition",
+        GlUtil.getNormalizedCoordinateBounds(),
+        GlUtil.HOMOGENEOUS_COORDINATE_VECTOR_SIZE);
   }
 
   @Override

demos/transformer/src/withMediaPipe/java/androidx/media3/demo/transformer/MediaPipeFrameProcessor.java

@@ -144,7 +144,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
       glProgram.setBufferAttribute(
           "aFramePosition",
           GlUtil.getNormalizedCoordinateBounds(),
-          GlUtil.RECTANGLE_VERTICES_COUNT);
+          GlUtil.HOMOGENEOUS_COORDINATE_VECTOR_SIZE);
       glProgram.bindAttributesAndUniforms();
       GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, /* first= */ 0, /* count= */ 4);
       GlUtil.checkGlError();

library/common/src/main/java/com/google/android/exoplayer2/util/GlUtil.java

@@ -52,8 +52,8 @@ public final class GlUtil {
   /** Whether to throw a {@link GlException} in case of an OpenGL error. */
   public static boolean glAssertionsEnabled = false;
 
-  /** Number of vertices in a rectangle. */
-  public static final int RECTANGLE_VERTICES_COUNT = 4;
+  /** Number of elements in a 3d homogeneous coordinate vector describing a vertex. */
+  public static final int HOMOGENEOUS_COORDINATE_VECTOR_SIZE = 4;
 
   /** Length of the normalized device coordinate (NDC) space, which spans from -1 to 1. */
   public static final float LENGTH_NDC = 2f;

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/ExternalCopyFrameProcessor.java

@@ -77,7 +77,9 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     glProgram.setSamplerTexIdUniform("uTexSampler", inputTexId, /* texUnitIndex= */ 0);
     // Draw the frame on the entire normalized device coordinate space, from -1 to 1, for x and y.
     glProgram.setBufferAttribute(
-        "aFramePosition", GlUtil.getNormalizedCoordinateBounds(), GlUtil.RECTANGLE_VERTICES_COUNT);
+        "aFramePosition",
+        GlUtil.getNormalizedCoordinateBounds(),
+        GlUtil.HOMOGENEOUS_COORDINATE_VECTOR_SIZE);
     if (enableExperimentalHdrEditing) {
       // In HDR editing mode the decoder output is sampled in YUV.
       glProgram.setFloatsUniform("uColorTransform", MATRIX_YUV_TO_BT2020_COLOR_TRANSFORM);

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/MatrixTransformationFrameProcessor.java

@@ -84,7 +84,9 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     glProgram.setSamplerTexIdUniform("uTexSampler", inputTexId, /* texUnitIndex= */ 0);
     // Draw the frame on the entire normalized device coordinate space, from -1 to 1, for x and y.
     glProgram.setBufferAttribute(
-        "aFramePosition", GlUtil.getNormalizedCoordinateBounds(), GlUtil.RECTANGLE_VERTICES_COUNT);
+        "aFramePosition",
+        GlUtil.getNormalizedCoordinateBounds(),
+        GlUtil.HOMOGENEOUS_COORDINATE_VECTOR_SIZE);
   }
 
   @Override