Updating texture validation to account for sampler objects in ES3

gpu/command_buffer/service/gles2_cmd_decoder.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <stdio.h>
 
 #include <algorithm>
 #include <cmath>
@@ skipping 1892 matching lines @@
   // and allow context preemption and GPU watchdog checks in GpuScheduler().
   void ExitCommandProcessingEarly() { commands_to_process_ = 0; }
 
   void ProcessPendingReadPixels(bool did_finish);
   void FinishReadPixels(const cmds::ReadPixels& c, GLuint buffer);
 
   void DoBindFragmentInputLocationCHROMIUM(GLuint program_id,
                                            GLint location,
                                            const std::string& name);
 
+  const SamplerState* GetSamplerStateForTextureUnit(GLenum target, GLuint unit);
+
   // Generate a member function prototype for each command in an automated and
   // typesafe way.
 #define GLES2_CMD_OP(name) \
   Error Handle##name(uint32 immediate_data_size, const void* data);
 
   GLES2_COMMAND_LIST(GLES2_CMD_OP)
 
   #undef GLES2_CMD_OP
 
   // The GL context this decoder renders to on behalf of the client.
@@ skipping 5726 matching lines @@
           "GLES2DecoderImpl::DoCopyTexImageIfNeeded", GetErrorState());
       glBindTexture(textarget, texture->service_id());
       DoCopyTexImage(texture, textarget, image);
       RestoreCurrentTextureBindings(&state_, textarget);
     }
   }
 }
 
 bool GLES2DecoderImpl::PrepareTexturesForRender() {
   DCHECK(state_.current_program.get());
-  if (!texture_manager()->HaveUnrenderableTextures() &&

[piman, 2015/12/14 14:04:14]

This early exit is pretty important for performance, since this is called for
every single draw call - in the general case where the application correctly
defines its textures, this used to early exit. If not, we have to iterate over
every single texture unit, of which there can be a lot (e.g. NVIDIA).

How can we keep that property?

[bajones, 2015/12/14 17:40:38]

For ES3 we can't evaluate this ahead of time because it depends on both the
textures _and_ the samplers bound. We could try and update the value any time a
texture or sampler binding changes, but that would probably be nearly as much or
more work than simply checking it here at draw time. At least here we only have
to check the texture units used by the current shader program. (Not for every
unit supported by the hardware, as you feared.)

A previous iteration of this patch attempted to keep this check for ES2 contexts
and bypassed it for ES3, but that ended up tracking whether a texture was
created with an ES2 context or a ES3 context, which zmo@ pointed out was faulty
logic because said textures may be shared between contexts via mailbox. After
some discussion we felt that the additional validation overhead here was small
enough that it was worth the reduced code complexity. (We're also hoping to
simply defer this logic to ANGLE entirely in the near future.)

I'm happy to hear any alternative suggestions you have, though! I do believe
there's room for improvement here.

-      !texture_manager()->HaveImages()) {
+  if (!texture_manager()->HaveImages()) {
     return true;
   }
   bool textures_set = false;
   const Program::SamplerIndices& sampler_indices =
      state_.current_program->sampler_indices();
   for (size_t ii = 0; ii < sampler_indices.size(); ++ii) {
     const Program::UniformInfo* uniform_info =
         state_.current_program->GetUniformInfo(sampler_indices[ii]);
     DCHECK(uniform_info);
     for (size_t jj = 0; jj < uniform_info->texture_units.size(); ++jj) {
       GLuint texture_unit_index = uniform_info->texture_units[jj];
       if (texture_unit_index < state_.texture_units.size()) {
         TextureUnit& texture_unit = state_.texture_units[texture_unit_index];
         TextureRef* texture_ref =
             texture_unit.GetInfoForSamplerType(uniform_info->type).get();
         GLenum textarget = GetBindTargetForSamplerType(uniform_info->type);
-        if (!texture_ref || !texture_manager()->CanRender(texture_ref)) {
+        const SamplerState* sampler_state = GetSamplerStateForTextureUnit(
+            uniform_info->type, texture_unit_index);
+        if (!texture_ref ||
+            !texture_manager()->CanRenderWithSampler(
+                texture_ref, sampler_state)) {
           textures_set = true;
           glActiveTexture(GL_TEXTURE0 + texture_unit_index);
           glBindTexture(
               textarget,
               texture_manager()->black_texture_id(uniform_info->type));
           if (!texture_ref) {
             LOCAL_RENDER_WARNING(
                 std::string("there is no texture bound to the unit ") +
                 base::UintToString(texture_unit_index));
           } else {
@@ skipping 35 matching lines @@
   for (size_t ii = 0; ii < sampler_indices.size(); ++ii) {
     const Program::UniformInfo* uniform_info =
         state_.current_program->GetUniformInfo(sampler_indices[ii]);
     DCHECK(uniform_info);
     for (size_t jj = 0; jj < uniform_info->texture_units.size(); ++jj) {
       GLuint texture_unit_index = uniform_info->texture_units[jj];
       if (texture_unit_index < state_.texture_units.size()) {
         TextureUnit& texture_unit = state_.texture_units[texture_unit_index];
         TextureRef* texture_ref =
             texture_unit.GetInfoForSamplerType(uniform_info->type).get();
-        if (!texture_ref || !texture_manager()->CanRender(texture_ref)) {
+        const SamplerState* sampler_state = GetSamplerStateForTextureUnit(
+            uniform_info->type, texture_unit_index);
+        if (!texture_ref ||
+            !texture_manager()->CanRenderWithSampler(
+                texture_ref, sampler_state)) {
           glActiveTexture(GL_TEXTURE0 + texture_unit_index);
           // Get the texture_ref info that was previously bound here.
           texture_ref = texture_unit.bind_target == GL_TEXTURE_2D
                             ? texture_unit.bound_texture_2d.get()
                             : texture_unit.bound_texture_cube_map.get();
           glBindTexture(texture_unit.bind_target,
                         texture_ref ? texture_ref->service_id() : 0);
           continue;
         }
       }
@@ skipping 7905 matching lines @@
   if (location < 0 ||
       static_cast<uint32>(location) >= group_->max_varying_vectors() * 4) {
     LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, kFunctionName,
                        "location out of range");
     return;
   }
 
   program->SetFragmentInputLocationBinding(name, location);
 }
 
+const SamplerState* GLES2DecoderImpl::GetSamplerStateForTextureUnit(
+    GLenum target, GLuint unit) {
+  if (features().enable_samplers) {
+    Sampler* sampler = state_.sampler_units[unit].get();
+    if (sampler)
+      return sampler->sampler_state();
+  }
+  TextureUnit& texture_unit = state_.texture_units[unit];
+  TextureRef* texture_ref = texture_unit.GetInfoForSamplerType(target).get();
+  if (texture_ref)
+    return texture_ref->texture()->sampler_state();
+
+  return nullptr;
+}
+
 error::Error GLES2DecoderImpl::HandleBindFragmentInputLocationCHROMIUMBucket(
     uint32 immediate_data_size,
     const void* cmd_data) {
   const gles2::cmds::BindFragmentInputLocationCHROMIUMBucket& c =
       *static_cast<const gles2::cmds::BindFragmentInputLocationCHROMIUMBucket*>(
           cmd_data);
   if (!features().chromium_path_rendering) {
     return error::kUnknownCommand;
   }
 
@@ skipping 116 matching lines @@
   return error::kNoError;
 }
 
 // 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.
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu