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authorKeith Whitwell <keith@tungstengraphics.com>2001-07-12 22:09:21 +0000
committerKeith Whitwell <keith@tungstengraphics.com>2001-07-12 22:09:21 +0000
commit1182ffeec39bf419928ba862c225e80a439fee7a (patch)
treeaf9e3f9019e3c59cb73d770eb60e94c5c77bdd25 /src/mesa/swrast_setup/NOTES
parentfae7b778b81b686ef419f971064b5fe12fb4ead3 (diff)
Rename some of the tnl->Driver.* functions to tnl->Driver.Render.*, to make it
clear that these are owned by t_vb_render.c. Make swrast_setup opaque - it now hooks itself directly into tnl->Driver.Render.*. Add a _swsetup_Wakeup() call that does this. Update X11 (tested), osmesa and FX drivers for this change. FX compiles but is probably broken as the changes there are large. It was the only remaining driver that used the internal _swsetup_ functions for interp and copy_pv. This usage has been replaced with code from the DRI tdfx driver.
Diffstat (limited to 'src/mesa/swrast_setup/NOTES')
-rw-r--r--src/mesa/swrast_setup/NOTES79
1 files changed, 32 insertions, 47 deletions
diff --git a/src/mesa/swrast_setup/NOTES b/src/mesa/swrast_setup/NOTES
index 4445b332d9..c6cb4ab348 100644
--- a/src/mesa/swrast_setup/NOTES
+++ b/src/mesa/swrast_setup/NOTES
@@ -6,10 +6,8 @@ swrast vertices from the t&l vertex_buffer structs, and to use them to
perform triangle setup functions not implemented in the software
rasterizer.
-The module provides a RasterSetup function to plug into the t&l driver
-interface. This hook had previously been used for hardware
-rasterizers, with the software rasterizer taking its data directly
-from the vertex buffer.
+The module implements a full set of functions to plug into the
+t_vb_render.c driver interface (tnl->Driver.Render.*).
There are strong advantages to decoupling the software rasterizer from
the t&l module, primarily allowing hardware drivers better control
@@ -18,63 +16,50 @@ rasterizer in the t&l module, allowing the two modules to evolve
independently and allowing either to be substituted with equivalent
functionality from another codebase.
-This module provides helpers for triangle/quad setup for offset,
-unfilled and twoside-lit triangles. The software rasterizer doesn't
-handle these primitives directly.
+This module implements triangle/quad setup for offset, unfilled and
+twoside-lit triangles. The software rasterizer doesn't handle these
+primitives directly.
-Hardware rasterization drivers probably have little use for this
-module. Rather, they might provide a layer that translates their
-native (hardware) vertices to swrast vertices before calling into the
-swrast module for fallbacks.
+Hardware rasterization drivers typically use this module in situations
+where no hardware rasterization is possible, ie during total
+fallbacks.
STATE
-This module associates an array of SWvertex structs with each VB.
-Thus there are:
-
- GLboolean _swsetup_RegisterVB( struct vertex_buffer *VB );
- void _swsetup_UnregisterVB( struct vertex_buffer *VB );
-
-Which must be called to create and destroy internal vertex storage for
-this module.
-
-To create and destroy the module itself:
+To create and destroy the module:
GLboolean _swsetup_CreateContext( GLcontext *ctx );
void _swsetup_DestroyContext( GLcontext *ctx );
-Like the software rasterizer, this module tracks state changes
-internally and maintains a set of entry points which will always
-reflect the current state. For this to work, the driver must call:
-
- void _swsetup_InvalidateState( GLcontext *ctx, GLuint new_state );
+The module is not active by default, and must be installed by calling
+_swrast_Wakeup(). This function installs internal swrast_setup
+functions into all the tnl->Driver.Render driver hooks, thus taking
+over the task of rasterization entirely:
-SERVICES
+ void _swrast_Wakeup( GLcontext *ctx );
-The module provides the following entrypoints:
+
+This module tracks state changes internally and maintains derived
+values based on the current state. For this to work, the driver
+ensure the following funciton is called whenever the state changes and
+the swsetup module is 'awake':
- void _swrast_RasterSetup( struct vertex_buffer *VB,
- GLuint start, GLuint end );
-
-Build SWvertices for <VB> between indices start and end.
-
- void _swsetup_Quad( GLcontext *ctx, GLuint v0, GLuint v1,
- GLuint v2, GLuint v3, GLuint pv );
-
- void _swsetup_Triangle( GLcontext *ctx, GLuint v0, GLuint v1,
- GLuint v2, GLuint pv );
+ void _swsetup_InvalidateState( GLcontext *ctx, GLuint new_state );
- void _swsetup_Line( GLcontext *ctx, GLuint v0, GLuint v1, GLuint pv );
+There is no explicit call to put the swsetup module to sleep. Simply
+install other function pointers into all the tnl->Driver.Render.*
+hooks, and (optionally) cease calling _swsetup_InvalidateState().
+DRIVER INTERFACE
- void _swsetup_Points( GLcontext *ctx, GLuint first, GLuint last );
+The module offers a minimal driver interface:
-Draw quad, triangle, line, points. Note that these are in the format
-expected by core mesa. The Quad and Triangle functions handle
-unfilled, offset, twoside-lit and flat-shaded primitives correctly.
+ void (*Start)( GLcontext *ctx );
+ void (*Finish)( GLcontext *ctx );
+
+These are called before and after the completion of all swrast drawing
+activity. As swrast doesn't call callbacks during triangle, line or
+point rasterization, these are necessary to provide locking hooks for
+some drivers. They may otherwise be left null.
-These functions can thus be plugged into the ctx->Driver struct and
-left permanently in place, providing the InvalidateState() routine is
-correctly called on state changes.
- \ No newline at end of file