1 // Copyright 2018 Google LLC 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef THIRD_PARTY_QUIC_TRACE_TOOLS_PROGRAM_STATE_H_ 16 #define THIRD_PARTY_QUIC_TRACE_TOOLS_PROGRAM_STATE_H_ 17 18 #include "tools/render/geometry_util.h" 19 #include "tools/render/sdl_util.h" 20 21 namespace quic_trace { 22 namespace render { 23 24 extern const char* kProgramStateData; 25 26 // The global state of the program that every component and shader has access 27 // to. There are some requirements regarding to how the format of this struct 28 // should be altered: 29 // 1. It should be kept in sync with the GLSL definition in .cc file. 30 // 2. There are some alignment rules that you have to follow, which are 31 // somewhat elaborate (search "std140" for more details), but the 32 // relevant part is that it's 4 bytes for floats and 8 bytes for 2D vectors. 33 struct ProgramStateData { 34 // Size of the program window in pixels. 35 vec2 window = vec2{1280.f, 720.f}; 36 // Starting point, in axis units (us/bytes), of the part of the trace that is 37 // currently shown. 38 vec2 offset = vec2{0.f, 0.f}; 39 // Size of the portion of the trace that is currently shown, in pixels. 40 vec2 viewport = vec2{0.f, 0.f}; 41 // The factor by which UI elements need to be scaled due to the DPI. 42 alignas(sizeof(float)) float dpi_scale = 1.f; 43 }; 44 45 // A wrapper around ProgramStateData for the consumers of the data. Allows 46 // access to the members of ProgramStateData as well as the copy of them in GPU 47 // memory. 48 class ProgramState { 49 public: 50 ProgramState(const ProgramStateData* data); 51 ProgramState(const ProgramState&) = delete; 52 ProgramState& operator=(const ProgramState&) = delete; 53 window()54 const vec2& window() const { return data_->window; } offset()55 const vec2& offset() const { return data_->offset; } viewport()56 const vec2& viewport() const { return data_->viewport; } dpi_scale()57 float dpi_scale() const { return data_->dpi_scale; } 58 ScaleForDpi(int value)59 int ScaleForDpi(int value) const { 60 return std::round(data_->dpi_scale * value); 61 } 62 63 // Binds the Uniform Buffer Object with |data_| onto the specified shader 64 // program. 65 void Bind(const GlProgram& program) const; 66 // Copies |data_| into |buffer_|. 67 void Refresh(); 68 69 private: 70 // Data on host. 71 const ProgramStateData* data_; 72 // Handle to data on the device. 73 GlUniformBuffer buffer_; 74 }; 75 76 } // namespace render 77 } // namespace quic_trace 78 79 #endif // THIRD_PARTY_QUIC_TRACE_TOOLS_PROGRAM_STATE_H_ 80