Remove redundant attribute from matrix transformation vertex shader.

The texture coordinates can be derived from the frame coordinates.

PiperOrigin-RevId: 446770538

demos/transformer/src/main/assets/vertex_shader_copy_es2.glsl

@@ -16,9 +16,8 @@
 // ES 2 vertex shader that leaves the coordinates unchanged.
 
 attribute vec4 aFramePosition;
-attribute vec4 aTexSamplingCoord;
 varying vec2 vTexSamplingCoord;
 void main() {
   gl_Position = aFramePosition;
-  vTexSamplingCoord = aTexSamplingCoord.xy;
+  vTexSamplingCoord = vec2(aFramePosition.x * 0.5 + 0.5, aFramePosition.y * 0.5 + 0.5);
 }

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

@@ -102,8 +102,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     // 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);
-    glProgram.setBufferAttribute(
-        "aTexSamplingCoord", GlUtil.getTextureCoordinateBounds(), GlUtil.RECTANGLE_VERTICES_COUNT);
     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

@@ -88,8 +88,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     // 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);
-    glProgram.setBufferAttribute(
-        "aTexSamplingCoord", GlUtil.getTextureCoordinateBounds(), GlUtil.RECTANGLE_VERTICES_COUNT);
   }
 
   @Override

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

@@ -145,10 +145,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
           "aFramePosition",
           GlUtil.getNormalizedCoordinateBounds(),
           GlUtil.RECTANGLE_VERTICES_COUNT);
-      glProgram.setBufferAttribute(
-          "aTexSamplingCoord",
-          GlUtil.getTextureCoordinateBounds(),
-          GlUtil.RECTANGLE_VERTICES_COUNT);
       glProgram.bindAttributesAndUniforms();
       GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, /* first= */ 0, /* count= */ 4);
       GlUtil.checkGlError();

library/transformer/src/main/assets/shaders/vertex_shader_tex_transform_es2.glsl

@@ -18,10 +18,10 @@
 // locations.
 
 attribute vec4 aFramePosition;
-attribute vec4 aTexSamplingCoord;
 uniform mat4 uTexTransform;
 varying vec2 vTexSamplingCoord;
 void main() {
   gl_Position = aFramePosition;
-  vTexSamplingCoord = (uTexTransform * aTexSamplingCoord).xy;
+  vec4 texturePosition = vec4(aFramePosition.x * 0.5 + 0.5, aFramePosition.y * 0.5 + 0.5, 0.0, 1.0);
+  vTexSamplingCoord = (uTexTransform * texturePosition).xy;
 }

library/transformer/src/main/assets/shaders/vertex_shader_tex_transform_es3.glsl

@@ -18,10 +18,10 @@
 // locations.
 
 in vec4 aFramePosition;
-in vec4 aTexSamplingCoord;
 uniform mat4 uTexTransform;
 out vec2 vTexSamplingCoord;
 void main() {
   gl_Position = aFramePosition;
-  vTexSamplingCoord = (uTexTransform * aTexSamplingCoord).xy;
+  vec4 texturePosition = vec4(aFramePosition.x * 0.5 + 0.5, aFramePosition.y * 0.5 + 0.5, 0.0, 1.0);
+  vTexSamplingCoord = (uTexTransform * texturePosition).xy;
 }

library/transformer/src/main/assets/shaders/vertex_shader_transformation_es2.glsl

@@ -17,10 +17,9 @@
 // uTransformationMatrix.
 
 attribute vec4 aFramePosition;
-attribute vec4 aTexSamplingCoord;
 uniform mat4 uTransformationMatrix;
 varying vec2 vTexSamplingCoord;
 void main() {
   gl_Position = uTransformationMatrix * aFramePosition;
-  vTexSamplingCoord = aTexSamplingCoord.xy;
+  vTexSamplingCoord = vec2(aFramePosition.x * 0.5 + 0.5, aFramePosition.y * 0.5 + 0.5);
 }

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

@@ -80,8 +80,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     // 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);
-    glProgram.setBufferAttribute(
-        "aTexSamplingCoord", GlUtil.getTextureCoordinateBounds(), GlUtil.RECTANGLE_VERTICES_COUNT);
     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

@@ -87,8 +87,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     // 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);
-    glProgram.setBufferAttribute(
-        "aTexSamplingCoord", GlUtil.getTextureCoordinateBounds(), GlUtil.RECTANGLE_VERTICES_COUNT);
   }
 
   @Override