Chapter 12. Housekeeping Routines 135

Chapter 12. Housekeeping Routines 135
1In This Chapter 135
2Retrieving Configuration Information 135
1Which Glide Release? 135
2How Big a Screen? 135
3Changing the y Origin 136
4Checking System Status 136
5Utilizing Two Displays 137
6Monitoring System Performance 138
Chapter 13. Glide Utilities 139
1In This Chapter 139
2A Higher Level Color Combine Function 139
3A Higher Level Alpha Combine Function 140
4A Higher Level Texture Combine Function 141
5Allocating Texture Memory 142
1Resetting Texture Memory 143
6Downloading Textures 143
1Changing Mipmap Attributes 143
2Retrieving Information about Mipmaps 144
Chapter 14. Programming Tips and Techniques 147
1In This Chapter 147
2Floating Point Vertex Snapping and Area Calculations 147
Example Programming Tips and Techniques.1 Snapping coordinates to .0625 resolution. 147
Example Programming Tips and Techniques.2 Masking off precision control bits on Intel processors. 148
Example Programming Tips and Techniques.3 A portable way to snap coordinates to .0625 resolution. 148
3Avoiding Redundant State Setting 148
4Avoiding Screen Clears by Rendering Background Polygons 148
5Using LOD Bias To Control Texture Aliasing 149
6Linear z Buffering and Coordinate System Ranges 149
7State Coherency and Contention Between Processes 149
3Appendix A. A Sample Program 151
4Appendix B. Glide State Constants 153
5Glossary 157
6Index 161

Figure An Introduction to Glide.1 Voodoo Graphics system configurations. 3
Figure An Introduction to Glide.2 The pixel pipeline. 5
Figure Getting Started.1 Locating the origin. 18
Figure Getting Started.2 Logical layout of the linear frame buffer. 22
Figure Rendering Primitives.1 Specifying a clipping window. 28
Figure Rendering Primitives.2 Pixel rendering. 30
Figure Rendering Primitives.3 Polygons. 32
Figure Rendering Primitives.4 Polygon orientation and the sign of the area. 33
Figure Rendering Primitives.5 Aliased and anti-aliased lines. 35
Figure Rendering Primitives.6 Pixel coverage and lines. 35
Figure Texture Mapping.1 TMU connectivity. 78
Figure Texture Mapping.2 Mapping texels onto texture maps. 81
Figure Texture Mapping.3 Point sampling and bilinear filtering. 83
Figure Texture Mapping.4 Texture clamping. 84
Figure Texture Mapping.5 Mipmaps. 86
Figure Managing Texture Memory.1 The color palette. 99
Figure Managing Texture Memory.2 The size of a mipmap depends on the setting of the evenOdd flag. 102
Figure Managing Texture Memory.3 Downloading a mipmap. 105
Figure Managing Texture Memory.4 Replacing a single LOD. 107
Figure Managing Texture Memory.5 Replacing a few rows of an LOD. 108
Figure Accessing the Linear Frame Buffer.1 Reading from and writing to the LFB. 121
Figure Accessing the Linear Frame Buffer.2 Frame buffer writes: encoding the location of the origin as the sign of the strideInBytes. 133
Figure Housekeeping Routines .1 The Voodoo Graphics status register. 137