Reland: Implement helper functionalities for computing image size with ES3 settings.

This will be used in ReadPixels, Tex{Sub}Image* in followup CLs.

Original reviewed CL is https://codereview.chromium.org/1508953002/

BUG=429053,563714
TEST=gpu_unittests
TBR=piman@chromium.org

Review URL: https://codereview.chromium.org/1513013002

Cr-Commit-Position: refs/heads/master@{#364200}

1 files changed, 22 insertions, 0 deletions

diff --git a/gpu/command_buffer/service/context_state.cc b/gpu/command_buffer/service/context_state.cc
index b93a372..4cbf294 100644
--- a/gpu/command_buffer/service/context_state.cc
+++ b/gpu/command_buffer/service/context_state.cc
@@ -594,6 +594,28 @@ void ContextState::UnbindSampler(Sampler* sampler) {
   }
 }
 
+PixelStoreParams ContextState::GetPackParams() {
+  PixelStoreParams params;
+  params.alignment = pack_alignment;
+  params.row_length = pack_row_length;
+  params.skip_pixels = pack_skip_pixels;
+  params.skip_rows = pack_skip_rows;
+  return params;
+}
+
+PixelStoreParams ContextState::GetUnpackParams(Dimension dimension) {
+  PixelStoreParams params;
+  params.alignment = unpack_alignment;
+  params.row_length = unpack_row_length;
+  params.skip_pixels = unpack_skip_pixels;
+  params.skip_rows = unpack_skip_rows;
+  if (dimension == k3D) {
+    params.image_height = unpack_image_height;
+    params.skip_images = unpack_skip_images;
+  }
+  return params;
+}
+
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.