| // Copyright 2017 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef COBALT_RENDERER_RASTERIZER_EGL_DRAW_OBJECT_H_ |
| #define COBALT_RENDERER_RASTERIZER_EGL_DRAW_OBJECT_H_ |
| |
| #include <GLES2/gl2.h> |
| |
| #include "base/callback.h" |
| #include "base/optional.h" |
| #include "cobalt/base/type_id.h" |
| #include "cobalt/math/matrix3_f.h" |
| #include "cobalt/math/rect.h" |
| #include "cobalt/render_tree/color_rgba.h" |
| #include "cobalt/render_tree/rounded_corners.h" |
| #include "cobalt/renderer/backend/egl/texture.h" |
| #include "cobalt/renderer/rasterizer/egl/graphics_state.h" |
| #include "cobalt/renderer/rasterizer/egl/shader_program_manager.h" |
| |
| namespace cobalt { |
| namespace renderer { |
| namespace rasterizer { |
| namespace egl { |
| |
| // Base type to rasterize various objects via GL commands. |
| class DrawObject { |
| public: |
| typedef base::optional<render_tree::RoundedCorners> OptionalRoundedCorners; |
| |
| // Callback to get a scratch "1D" texture of the given |size|. If such a |
| // request was previously fulfilled for the relevant render tree node, then |
| // the cached |texture| and |region| will be returned, and |is_new| will be |
| // false; this is a hint as to whether the texture region needs to be |
| // initialized. If the request succeeded, then |texture| will point to a 2D |
| // texture whose |region| is a row meeting the size requirement; otherwise, |
| // |texture| will be nullptr. |
| struct TextureInfo { |
| const backend::TextureEGL* texture; |
| math::RectF region; |
| bool is_new; |
| }; |
| typedef base::Callback<void(float size, TextureInfo* out_texture_info)> |
| GetScratchTextureFunction; |
| |
| // Structure containing the common attributes for all DrawObjects. |
| struct BaseState { |
| BaseState(); |
| BaseState(const BaseState& other); |
| |
| math::Matrix3F transform; |
| math::Rect scissor; |
| |
| // |rounded_scissor_rect| is only relevant when |rounded_scissor_corners| |
| // exists. |
| math::RectF rounded_scissor_rect; |
| OptionalRoundedCorners rounded_scissor_corners; |
| |
| float opacity; |
| }; |
| |
| virtual ~DrawObject() {} |
| |
| // Certain draw objects can be merged with others to reduce the number of |
| // draw calls issued. If TryMerge returns true, then |other| can be discarded. |
| base::TypeId GetMergeTypeId() const { return merge_type_; } |
| virtual bool TryMerge(DrawObject* other) { return false; } |
| |
| // This stage is used to update the vertex buffer for the rasterize |
| // stage. Vertex data is handled by the GraphicsState to minimize the number |
| // of vertex buffers needed. Once this stage is executed, the rasterizer will |
| // then notify the GraphicsState to send all vertex data from all draw |
| // objects to the GPU. |
| virtual void ExecuteUpdateVertexBuffer(GraphicsState* graphics_state, |
| ShaderProgramManager* program_manager) = 0; |
| |
| // This stage is responsible for issuing the GPU commands to do the actual |
| // rendering. |
| virtual void ExecuteRasterize(GraphicsState* graphics_state, |
| ShaderProgramManager* program_manager) = 0; |
| |
| // Return a TypeId that can be used to sort draw objects in order to minimize |
| // state changes. This may be the class' TypeId, or the TypeId of the shader |
| // program which the class uses. |
| virtual base::TypeId GetTypeId() const = 0; |
| |
| protected: |
| // Structures describing vertex data for rendering rounded rectangles. |
| struct RCorner { |
| // Constructor to transform a RCorner value into a format which the |
| // shader function IsOutsideRCorner() expects. This expresses the current |
| // vertex position as a scaled offset relevant for the corner, and provides |
| // scalars to assist in calculating the antialiased edge. For more details, |
| // see function_is_outside_rcorner.inc. |
| RCorner(const float (&position)[2], const RCorner& init); |
| RCorner() {} |
| float x, y; |
| float rx, ry; |
| }; |
| struct RRectAttributes { |
| math::RectF bounds; // The region in which to use the rcorner data. |
| RCorner rcorner; |
| }; |
| |
| DrawObject(); |
| explicit DrawObject(const BaseState& base_state); |
| |
| // Remove scale from the transform, and return the scale vector. |
| math::Vector2dF RemoveScaleFromTransform(); |
| |
| // Utility function to get the render color for the blend modes that will |
| // be used. These modes expect alpha to be pre-multiplied. |
| static render_tree::ColorRGBA GetDrawColor( |
| const render_tree::ColorRGBA& color) { |
| return render_tree::ColorRGBA(color.r() * color.a(), color.g() * color.a(), |
| color.b() * color.a(), color.a()); |
| } |
| |
| // Return a uint32_t suitable to be transferred as 4 unsigned bytes |
| // representing color to a GL shader. |
| static uint32_t GetGLRGBA(float r, float g, float b, float a); |
| static uint32_t GetGLRGBA(const render_tree::ColorRGBA& color) { |
| return GetGLRGBA(color.r(), color.g(), color.b(), color.a()); |
| } |
| |
| // Get the vertex attributes to use to draw the given rounded rect. Each |
| // corner uses a different attribute. These RCorner values must be transformed |
| // before being passed to the shader. (See RCorner constructor.) |
| static void GetRRectAttributes(const math::RectF& bounds, |
| math::RectF rect, render_tree::RoundedCorners corners, |
| RRectAttributes (&out_attributes)[4]); |
| |
| // Get the vertex attributes to draw the given rounded rect excluding the |
| // inscribed rect. These RCorner values must be transformed before being |
| // passed to the shader. (See RCorner constructor.) |
| static void GetRRectAttributes(const math::RectF& bounds, |
| math::RectF rect, render_tree::RoundedCorners corners, |
| RRectAttributes (&out_attributes)[8]); |
| |
| BaseState base_state_; |
| |
| // Provide type information for use with TryMerge. Only DrawObjects that may |
| // be merged need to set this. |
| base::TypeId merge_type_; |
| |
| private: |
| // Return the RCorner values for the given rounded rect, and the normalized |
| // rect and corner values used. |
| static void GetRCornerValues(math::RectF* rect, |
| render_tree::RoundedCorners* corners, |
| RRectAttributes out_rcorners[4]); |
| }; |
| |
| } // namespace egl |
| } // namespace rasterizer |
| } // namespace renderer |
| } // namespace cobalt |
| |
| #endif // COBALT_RENDERER_RASTERIZER_EGL_DRAW_OBJECT_H_ |