gpu: Render to a framebuffer object instead of an offscreen surface in gpu_perftests.

gpu/perftests/texture_upload_perftest.cc

Index: gpu/perftests/texture_upload_perftest.cc
diff --git a/gpu/perftests/texture_upload_perftest.cc b/gpu/perftests/texture_upload_perftest.cc
index f691c9e76d91f1b744f2609309ba91266e15f8b2..36de48ab776816401ae9ad91ff4f7ab290a605b4 100644
--- a/gpu/perftests/texture_upload_perftest.cc
+++ b/gpu/perftests/texture_upload_perftest.cc
@@ -96,12 +96,30 @@ class TextureUploadPerfTest : public testing::Test {
   void SetUp() override {
     // Initialize an offscreen surface and a gl context.
     gfx::GLSurface::InitializeOneOff();
-    surface_ = gfx::GLSurface::CreateOffscreenGLSurface(size_);
+    surface_ = gfx::GLSurface::CreateOffscreenGLSurface(gfx::Size(4, 4));
     gl_context_ = gfx::GLContext::CreateGLContext(NULL,  // share_group
                                                   surface_.get(),
                                                   gfx::PreferIntegratedGpu);
-
     ui::ScopedMakeCurrent smc(gl_context_.get(), surface_.get());
+    glGenTextures(1, &color_texture_);
+    glBindTexture(GL_TEXTURE_2D, color_texture_);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, size_.width(), size_.height(), 0,
+                 GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
+
+    glGenFramebuffersEXT(1, &framebuffer_object_);
+    glBindFramebufferEXT(GL_FRAMEBUFFER, framebuffer_object_);
+
+    glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                              GL_TEXTURE_2D, color_texture_, 0);
+    DCHECK_EQ(static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE),
+              glCheckFramebufferStatusEXT(GL_FRAMEBUFFER));
+
+    glViewport(0, 0, size_.width(), size_.height());
+
     if (gpu_timing_.Initialize(gl_context_.get())) {
       LOG(INFO) << "Gpu timing initialized with timer type: "
                 << gpu_timing_.GetTimerTypeName();
@@ -110,7 +128,6 @@ class TextureUploadPerfTest : public testing::Test {
     } else {
       LOG(WARNING) << "Can't initialize gpu timing";
     }
-
     // Prepare a simple program and a vertex buffer that will be
     // used to draw a quad on the offscreen surface.
     vertex_shader_ = LoadShader(GL_VERTEX_SHADER, kVertexShader);
@@ -154,6 +171,13 @@ class TextureUploadPerfTest : public testing::Test {
     if (vertex_buffer_ != 0) {
       glDeleteShader(vertex_buffer_);
     }
+    if (framebuffer_object_ != 0) {

[reveman, 2015/02/18 16:21:33]

nit: I think just "if (framebuffer_object_)" is preferred but I can see "!= 0"
being used in this file already so you can keep this for consistency if you
like.

btw, do we really need all these "if" statements in TearDown? When is it OK for
framebuffer_object_ to be 0?

[Daniele Castagna, 2015/02/18 18:47:07]

We don't need them. I checked the documentation for all those functions and a
value of 0 is always ignored.

+      glBindFramebufferEXT(GL_FRAMEBUFFER, 0);
+      glDeleteFramebuffersEXT(1, &framebuffer_object_);
+    }
+    if (color_texture_ != 0) {

[reveman, 2015/02/18 16:21:33]

nit: maybe remove "!= 0"

[Daniele Castagna, 2015/02/18 18:47:07]

Removed all the if (blabla_ != 0)

+      glDeleteTextures(1, &color_texture_);
+    }
 
     gl_context_ = nullptr;
     surface_ = nullptr;
@@ -167,6 +191,8 @@ class TextureUploadPerfTest : public testing::Test {
                                          const GLenum format,
                                          const GLenum type) {
     ui::ScopedMakeCurrent smc(gl_context_.get(), surface_.get());
+    DCHECK_GT(framebuffer_object_, 0u);

[reveman, 2015/02/18 16:21:33]

nit: DCHECK_NE as less than 0 is not possible

[Daniele Castagna, 2015/02/18 18:47:07]

Done.

+    glBindFramebufferEXT(GL_FRAMEBUFFER, framebuffer_object_);
 
     MeasurementTimers total_timers(&gpu_timing_);
     GLuint texture_id = 0;
@@ -178,8 +204,8 @@ class TextureUploadPerfTest : public testing::Test {
 
     glTexImage2D(GL_TEXTURE_2D, 0, format, size_.width(), size_.height(), 0,
                  format, type, &pixels[0]);
-    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     CheckNoGlError();
@@ -222,11 +248,13 @@ class TextureUploadPerfTest : public testing::Test {
     return measurements;
   }
 
-  const gfx::Size size_;  // for the offscreen surface and the texture
+  const gfx::Size size_;  // for the fbo and the texture
   scoped_refptr<gfx::GLContext> gl_context_;
   scoped_refptr<gfx::GLSurface> surface_;
   GPUTiming gpu_timing_;
 
+  GLuint color_texture_ = 0;
+  GLuint framebuffer_object_ = 0;
   GLuint vertex_shader_ = 0;
   GLuint fragment_shader_ = 0;
   GLuint program_object_ = 0;