| |
| /* |
| * Copyright 2015 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| |
| #ifndef SkLightingShader_DEFINED |
| #define SkLightingShader_DEFINED |
| |
| #include "SkPoint3.h" |
| #include "SkShader.h" |
| |
| class SK_API SkLightingShader { |
| public: |
| struct Light { |
| SkVector3 fDirection; // direction towards the light (+Z is out of the screen). |
| // If degenerate, it will be replaced with (0, 0, 1). |
| SkColor3f fColor; // linear (unpremul) color. Range is 0..1 in each channel. |
| }; |
| |
| /** Returns a shader that lights the diffuse and normal maps with a single light. |
| |
| It returns a shader with a reference count of 1. |
| The caller should decrement the shader's reference count when done with the shader. |
| It is an error for count to be < 2. |
| @param diffuse the diffuse bitmap |
| @param normal the normal map |
| @param light the light applied to the normal map |
| @param ambient the linear (unpremul) ambient light color. Range is 0..1/channel. |
| @param localMatrix the matrix mapping the textures to the dest rect |
| |
| NULL will be returned if: |
| either 'diffuse' or 'normal' are empty |
| either 'diffuse' or 'normal' are too big (> 65535 on a side) |
| 'diffuse' and 'normal' aren't the same size |
| |
| The lighting equation is currently: |
| result = LightColor * DiffuseColor * (Normal * LightDir) + AmbientColor |
| |
| The normal map is currently assumed to be an 8888 image where the normal at a texel |
| is retrieved by: |
| N.x = R-127; |
| N.y = G-127; |
| N.z = B-127; |
| N.normalize(); |
| The +Z axis is thus encoded in RGB as (127, 127, 255) while the -Z axis is |
| (127, 127, 0). |
| */ |
| static SkShader* Create(const SkBitmap& diffuse, const SkBitmap& normal, |
| const SkLightingShader::Light& light, const SkColor3f& ambient, |
| const SkMatrix* localMatrix); |
| |
| SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP() |
| }; |
| |
| #endif |