HLSLand Pixel Shaders for XAML. Developers. Walt Ritscher O'REILLY* Farnham Koln Sebastopol. Beijing. Tokyo. Cambridge

Transcription

1 HLSLand Pixel Shaders for XAML Developers Walt Ritscher O'REILLY* Beijing Cambridge Farnham Koln Sebastopol Tokyo

2 Table of Contents Preface ix Foreword xv 1. ShaderlOl 1 Why Should XAML Developers Learn HLSL? 1 The Tale of the Shader 2 HLSL and DirectX 3 Understanding the Graphics Pipeline 5 XAML and Shaders Getting Started 11 Setting Up Your Development Computer 11 Silverlight Development 11 WPF Development 12 Expression Blend 4 12 Choosing a Shader Compiler 12 DirectX Compiler 12 WPF Build Task 13 Shazzam Shader Editor 13 Other Tools to Consider 13 FX Composer 13 NShader 14 Visual Studio A First Shader Project 15 Using Prebuilt Effects 16 Adding Effects 19 Debrief 22 Custom Shader 22 Create a Shader Algorithm 23

3 Compile the HLSL Code 24 Add to Visual Studio XAML Project 24 Create a.net Wrapper Class 25 Compile the Project 26 Instantiate the Shader Commonplace Pixel Shaders 29 A Word About Pseudocode 30 Our Sample Image Color Modification 30 Common Techniques Black, White, and Gray 32 Color Replacement 34 Color Enhancement and Correction 34 Distinctive Effects 36 Distortion and Displacement 37 Magnify 38 Embossed 39 Testing Distortion Effects 40 Other Displacement Effects 42 Blurs 42 Motion Blur 43 Zoom Blur 43 Sharpening 43 Generative Effects 43 Multiple Inputs 44 Sampler Transition 44 Texture Map 46 Color Combination 47 Photoshop Blend Modes 49 Darken Modes 49 Lighten Modes 51 Contrast Modes 52 Comparative Modes 52 Other Modes 52 Blend Modes in HLSL 53 Practical Uses for Shader Effects 53 Motion Blur in Moving Parts 54 Blurs to Emphasize UI Focus 54 Desaturate for Emphasis iv Table of Contents

4 4. How WPF and Silverlight Use Shaders 57 Framework Effects BlurEffect DropShadowEffect Nested Effects Multiple Effects on One Element 59 Expression Blend Effects 60 Using a Blend Effect 61 Custom Effects Creating a Custom ShaderEffect 63 Working with Samplers 65 Multi-Input Shaders 72 Understanding Sampler Size 73 Creating Parameterized Effects 75 Padding 77 Effect Mapping Using Expression Blend and Visual Studio with Shaders 85 Creating a Project 85 New Project 86 Adding Assets 87 Adding Effects 88 Setting Effect Properties Visual Studio Editor Using Custom Effects in Blend 92 Multi-Input Effects 94 Transition Effects in Blend 98 Create a State Group Add the States Set the Properties Adding a Transition Effect Using the Shazzam Shader Editor 103 UI Tour Create a Custom Shader Exploring the HLSL Code Editor 105 Compiling and Testing the Shader 106 Editor Status Bar 109 Exploring the Generated Code 109 Changing Options 110 Working with HLSL Parameters Table of Contents v

5 Testing Parameters 113 Default Values for Parameters 114 Shazzam Tags 115 Input Parameter Types 117 Influencing the.net Type 117 Multi-Input Shaders 119 Shader Loader 121 More Shazzam Tools 123 Copying the Files into a Visual Studio Project HLSL in Detail 125 Parallel Processing in Shaders 125 Parallelism and the GPU 126 One-Pixel-at-a-Time Algorithm 126 The Relationship Between DirectX and the GPU 127 Understanding Registers 127 Basic Structure of an HLSL Program 128 User-Defined Functions 129 Semantics 130 Data Types 132 Type Casting 138 Local Variables 139 Shader Inputs 139 TEXCOORD Input 139 Global Variables 140 Global Inputs 140 Texture and Sampler Input 141 Sampler Declarations 142 Other Code Constructs 143 Flow Control Branching 143 Flow Control Loops 144 Operators 144 Built-in Functions 145 Texture Functions 146 Math Functions 146 Useful Built-in Functions The Zen of Shader Programming 149 Zen of Pixel Programming Sampling a Pixel Color Sampling a Color from Another Texture vi Table of Contents

6 Colors 151 Color Channel Manipulation 151 Conditional Colors 152 Replace a Color 153 Other Color Modifier Examples 154 Coordinates 158 Distortion and Displacement Effects 165 Random Values 170 Noise Textures 172 Perlin Noise in Shaders A. Resources 181 B. Shazzam Settings 183 Table of Contents vii