blob: 912c8bb7b39c73a2cd288f85a309931461c794cc [file] [log] [blame]
* Copyright 2019 The Android Open Source Project
* 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
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* See the License for the specific language governing permissions and
* limitations under the License.
#pragma once
#include <math/vec4.h>
#include <renderengine/Mesh.h>
#include <ui/Rect.h>
namespace android {
namespace renderengine {
namespace gl {
* The shadow geometry logic and vertex generation code has been ported from skia shadow
* fast path OpenGL implementation to draw shadows around rects and rounded rects including
* circles.
* path: skia/src/gpu/GrRenderTargetContext.cpp GrRenderTargetContext::drawFastShadow
* Modifications made:
* - Switched to using std lib math functions
* - Fall off function is implemented in vertex shader rather than a shadow texture
* - Removed transformations applied on the caster rect since the caster will be in local
* coordinate space and will be transformed by the vertex shader.
enum RRectType {
struct Geometry {
vec4 fColor;
float fOuterRadius;
float fUmbraInset;
float fInnerRadius;
float fBlurRadius;
FloatRect fDevBounds;
RRectType fType;
bool fIsCircle;
bool fIsStroked;
std::unique_ptr<Geometry> getSpotShadowGeometry(const FloatRect& casterRect,
float casterCornerRadius, float casterZ,
bool casterIsTranslucent, const vec4& spotColor,
const vec3& lightPosition, float lightRadius);
std::unique_ptr<Geometry> getAmbientShadowGeometry(const FloatRect& casterRect,
float casterCornerRadius, float casterZ,
bool casterIsTranslucent,
const vec4& ambientColor);
int getVertexCountForGeometry(const Geometry& shadowGeometry);
int getIndexCountForGeometry(const Geometry& shadowGeometry);
void fillVerticesForGeometry(const Geometry& shadowGeometry, int vertexCount,
Mesh::VertexArray<vec2> position, Mesh::VertexArray<vec4> shadowColor,
Mesh::VertexArray<vec3> shadowParams);
void fillIndicesForGeometry(const Geometry& shadowGeometry, int indexCount,
int startingVertexOffset, uint16_t* indices);
* Maps shadow geometry 'alpha' varying (1 for darkest, 0 for transparent) to
* darkness at that spot. Values are determined by an exponential falloff
* function provided by UX.
* The texture is used for quick lookup in theshadow shader.
* textureData - filled with shadow texture data that needs to be at least of
* size textureWidth
* textureWidth - width of the texture, height is always 1
void fillShadowTextureData(uint8_t* textureData, size_t textureWidth);
} // namespace gl
} // namespace renderengine
} // namespace android