1 1.1 mrg INTRODUCTION 2 1.1 mrg 3 1.1 mrg Mesa's native software rasterizer. This module provides the fallback 4 1.1 mrg paths for rasterization operations and states that aren't accelerated 5 1.1 mrg in hardware drivers, and as the full rasterization engine in software 6 1.1 mrg drivers. 7 1.1 mrg 8 1.1 mrg The swrast module 'stands alone', relying only on interfaces to core 9 1.1 mrg mesa and it's own driver interface. It knows nothing about the tnl or 10 1.1 mrg other modules, allowing it to be used for fallback paths in future tnl 11 1.1 mrg schemes without modification. 12 1.1 mrg 13 1.1 mrg As well as providing triangle/line/point rasterization functionality, 14 1.1 mrg the module provides implementations of the pixel operations 15 1.1 mrg (ReadPixels, etc), and texture operations (CopyTexSubImage) which may 16 1.1 mrg be plugged in to the core Mesa driver interface where accelerated 17 1.1 mrg versions of these operations are unavailable. 18 1.1 mrg 19 1.1 mrg 20 1.1 mrg STATE 21 1.1 mrg 22 1.1 mrg To create and destroy the module: 23 1.1 mrg 24 1.1 mrg GLboolean _swrast_CreateContext( struct gl_context *ctx ); 25 1.1 mrg void _swrast_DestroyContext( struct gl_context *ctx ); 26 1.1 mrg 27 1.1 mrg This module tracks state changes internally and maintains derived 28 1.1 mrg values based on the current state. For this to work, the driver 29 1.1 mrg ensure the following funciton is called whenever the state changes and 30 1.1 mrg the swsetup module is 'awake': 31 1.1 mrg 32 1.1 mrg void _swrast_InvalidateState( struct gl_context *ctx, GLuint new_state ); 33 1.1 mrg 34 1.1 mrg There is no explicit call to put the swrast module to sleep. 35 1.1 mrg 36 1.1 mrg 37 1.1 mrg CUSTOMIZATION 38 1.1 mrg 39 1.1 mrg void (*choose_point)( struct gl_context * ); 40 1.1 mrg void (*choose_line)( struct gl_context * ); 41 1.1 mrg void (*choose_triangle)( struct gl_context * ); 42 1.1 mrg 43 1.1 mrg Drivers may add additional triangle/line/point functions to swrast by 44 1.1 mrg overriding these functions. It is necessary for the driver to be very 45 1.1 mrg careful that it doesn't return an inappropriate function, eg a 46 1.1 mrg rasterization function in feedback mode. See the X11 driver for 47 1.1 mrg examples. 48 1.1 mrg 49 1.1 mrg DRIVER INTERFACE 50 1.1 mrg 51 1.1 mrg The swrast device driver provides swrast primarily with span- and 52 1.1 mrg pixel- level interfaces to a framebuffer, with a few additional hooks 53 1.1 mrg for locking and setting the read buffer. 54 1.1 mrg 55 1.1 mrg See the definition of struct swrast_device_driver in swrast.h.
Indexes created Mon Jun 29 00:24:49 UTC 2026