From 9f888435b7dd568e767c7f4cdf531576127c92b7 Mon Sep 17 00:00:00 2001
From: MediaPipe Team <mediapipe-team@google.com>
Date: Mon, 27 Mar 2023 03:36:47 -0700
Subject: [PATCH] Internal change

PiperOrigin-RevId: 519674123
---
 mediapipe/gpu/BUILD               |  2 +-
 mediapipe/gpu/gl_quad_renderer.cc | 67 +++++++++++++++++++------------
 mediapipe/gpu/gl_quad_renderer.h  |  7 +++-
 3 files changed, 49 insertions(+), 27 deletions(-)

diff --git a/mediapipe/gpu/BUILD b/mediapipe/gpu/BUILD
index 9b538a7f..d74e8ad3 100644
--- a/mediapipe/gpu/BUILD
+++ b/mediapipe/gpu/BUILD
@@ -858,7 +858,7 @@ cc_library(
         ":scale_mode_cc_proto",
         ":shader_util",
         "//mediapipe/framework/port:ret_check",
-        "//mediapipe/framework/port:status",
+        "@com_google_absl//absl/status",
     ],
 )
 
diff --git a/mediapipe/gpu/gl_quad_renderer.cc b/mediapipe/gpu/gl_quad_renderer.cc
index 309b8323..ec779b59 100644
--- a/mediapipe/gpu/gl_quad_renderer.cc
+++ b/mediapipe/gpu/gl_quad_renderer.cc
@@ -87,6 +87,17 @@ absl::Status QuadRenderer::GlSetup(
   glGenVertexArrays(1, &vao_);
   glGenBuffers(2, vbo_);
 
+  glBindVertexArray(vao_);
+  glEnableVertexAttribArray(ATTRIB_VERTEX);
+  glEnableVertexAttribArray(ATTRIB_TEXTURE_POSITION);
+
+  glBindBuffer(GL_ARRAY_BUFFER, vbo_[1]);
+  glBufferData(GL_ARRAY_BUFFER, sizeof(mediapipe::kBasicTextureVertices),
+               kBasicTextureVertices, GL_STATIC_DRAW);
+  glVertexAttribPointer(ATTRIB_TEXTURE_POSITION, 2, GL_FLOAT, 0, 0, nullptr);
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
+  glBindVertexArray(0);
+
   return absl::OkStatus();
 }
 
@@ -104,6 +115,7 @@ void QuadRenderer::GlTeardown() {
     vbo_[0] = 0;
     vbo_[1] = 0;
   }
+  rotation_ = std::nullopt;
 }
 
 absl::Status QuadRenderer::GlRender(float frame_width, float frame_height,
@@ -145,12 +157,42 @@ absl::Status QuadRenderer::GlRender(float frame_width, float frame_height,
       break;
   }
 
+  if (flip_texture) {
+    switch (rotation) {
+      case FrameRotation::kNone:  // Fall-through intended.
+      case FrameRotation::k180:
+        flip_vertical = !flip_vertical;
+        break;
+      case FrameRotation::k90:
+        flip_horizontal = !flip_horizontal;
+        break;
+      case FrameRotation::k270:
+        flip_horizontal = !flip_horizontal;
+        break;
+    }
+  }
   const int h_flip_factor = flip_horizontal ? -1 : 1;
   const int v_flip_factor = flip_vertical ? -1 : 1;
+
   GLfloat scale[] = {scale_width * h_flip_factor, scale_height * v_flip_factor,
                      1.0, 1.0};
   glUniform4fv(scale_unif_, 1, scale);
 
+  // Draw.
+
+  glBindVertexArray(vao_);
+  if (rotation != rotation_) {
+    rotation_ = rotation;
+    UpdateVertices(rotation);
+  }
+
+  glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+  glBindVertexArray(0);
+
+  return absl::OkStatus();
+}
+
+void QuadRenderer::UpdateVertices(FrameRotation rotation) const {
   // Choose vertices for rotation.
   const GLfloat* vertices;  // quad used to render the texture.
   switch (rotation) {
@@ -168,36 +210,11 @@ absl::Status QuadRenderer::GlRender(float frame_width, float frame_height,
       break;
   }
 
-  // Draw.
-
-  // TODO: In practice, our vertex attributes almost never change, so
-  // convert this to being actually static, with initialization done in the
-  // GLSetup.
-  glBindVertexArray(vao_);
-  glEnableVertexAttribArray(ATTRIB_VERTEX);
   glBindBuffer(GL_ARRAY_BUFFER, vbo_[0]);
   glBufferData(GL_ARRAY_BUFFER, sizeof(mediapipe::kBasicSquareVertices),
                vertices, GL_STATIC_DRAW);
   glVertexAttribPointer(ATTRIB_VERTEX, 2, GL_FLOAT, 0, 0, nullptr);
-
-  glEnableVertexAttribArray(ATTRIB_TEXTURE_POSITION);
-  glBindBuffer(GL_ARRAY_BUFFER, vbo_[1]);
-  glBufferData(
-      GL_ARRAY_BUFFER,
-      flip_texture ? sizeof(mediapipe::kBasicTextureVerticesFlipY)
-                   : sizeof(mediapipe::kBasicTextureVertices),
-      flip_texture ? kBasicTextureVerticesFlipY : kBasicTextureVertices,
-      GL_STATIC_DRAW);
-
-  glVertexAttribPointer(ATTRIB_TEXTURE_POSITION, 2, GL_FLOAT, 0, 0, nullptr);
-
-  glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
-  glDisableVertexAttribArray(ATTRIB_VERTEX);
-  glDisableVertexAttribArray(ATTRIB_TEXTURE_POSITION);
   glBindBuffer(GL_ARRAY_BUFFER, 0);
-  glBindVertexArray(0);
-
-  return absl::OkStatus();
 }
 
 absl::Status FrameRotationFromInt(FrameRotation* rotation, int degrees_ccw) {
diff --git a/mediapipe/gpu/gl_quad_renderer.h b/mediapipe/gpu/gl_quad_renderer.h
index 3d0e9d64..431757c7 100644
--- a/mediapipe/gpu/gl_quad_renderer.h
+++ b/mediapipe/gpu/gl_quad_renderer.h
@@ -15,7 +15,9 @@
 #ifndef MEDIAPIPE_GPU_GL_QUAD_RENDERER_H_
 #define MEDIAPIPE_GPU_GL_QUAD_RENDERER_H_
 
-#include "mediapipe/framework/port/status.h"
+#include <optional>
+
+#include "absl/status/status.h"
 #include "mediapipe/gpu/gl_base.h"
 #include "mediapipe/gpu/scale_mode.pb.h"
 
@@ -78,11 +80,14 @@ class QuadRenderer {
   void GlTeardown();
 
  private:
+  void UpdateVertices(FrameRotation rotation) const;
+
   GLuint program_ = 0;
   GLint scale_unif_ = -1;
   std::vector<GLint> frame_unifs_;
   GLuint vao_ = 0;          // vertex array object
   GLuint vbo_[2] = {0, 0};  // for vertex buffer storage
+  mutable std::optional<FrameRotation> rotation_;
 };
 
 absl::Status FrameRotationFromInt(FrameRotation* rotation, int degrees_ccw);