2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
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8 * copy of this software and associated documentation files (the "Software"),
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18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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27 * \file swrast/s_context.h
28 * \brief Software rasterization context and private types.
29 * \author Keith Whitwell <keith@tungstengraphics.com>
33 * \mainpage swrast module
35 * This module, software rasterization, contains the software fallback
36 * routines for drawing points, lines, triangles, bitmaps and images.
37 * All rendering boils down to writing spans (arrays) of pixels with
38 * particular colors. The span-writing routines must be implemented
39 * by the device driver.
51 typedef void (*texture_sample_func
)(GLcontext
*ctx
,
52 const struct gl_texture_object
*tObj
,
53 GLuint n
, const GLfloat texcoords
[][4],
54 const GLfloat lambda
[], GLchan rgba
[][4]);
56 typedef void (_ASMAPIP blend_func
)( GLcontext
*ctx
, GLuint n
,
58 GLvoid
*src
, const GLvoid
*dst
,
61 typedef void (*swrast_point_func
)( GLcontext
*ctx
, const SWvertex
*);
63 typedef void (*swrast_line_func
)( GLcontext
*ctx
,
64 const SWvertex
*, const SWvertex
*);
66 typedef void (*swrast_tri_func
)( GLcontext
*ctx
, const SWvertex
*,
67 const SWvertex
*, const SWvertex
*);
70 typedef void (*validate_texture_image_func
)(GLcontext
*ctx
,
71 struct gl_texture_object
*texObj
,
72 GLuint face
, GLuint level
);
77 * Bitmasks to indicate which rasterization options are enabled
81 #define ALPHATEST_BIT 0x001 /**< Alpha-test pixels */
82 #define BLEND_BIT 0x002 /**< Blend pixels */
83 #define DEPTH_BIT 0x004 /**< Depth-test pixels */
84 #define FOG_BIT 0x008 /**< Fog pixels */
85 #define LOGIC_OP_BIT 0x010 /**< Apply logic op in software */
86 #define CLIP_BIT 0x020 /**< Scissor or window clip pixels */
87 #define STENCIL_BIT 0x040 /**< Stencil pixels */
88 #define MASKING_BIT 0x080 /**< Do glColorMask or glIndexMask */
89 #define MULTI_DRAW_BIT 0x400 /**< Write to more than one color- */
90 /**< buffer or no buffers. */
91 #define OCCLUSION_BIT 0x800 /**< GL_HP_occlusion_test enabled */
92 #define TEXTURE_BIT 0x1000 /**< Texturing really enabled */
93 #define FRAGPROG_BIT 0x2000 /**< Fragment program enabled */
94 #define ATIFRAGSHADER_BIT 0x4000 /**< ATI Fragment shader enabled */
95 #define CLAMPING_BIT 0x8000 /**< Clamp colors to [0,1] */
98 #define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS| \
112 * \brief Per-context state that's private to the software rasterizer module.
116 /** Driver interface:
118 struct swrast_device_driver Driver
;
120 /** Configuration mechanisms to make software rasterizer match
121 * characteristics of the hardware rasterizer (if present):
123 GLboolean AllowVertexFog
;
124 GLboolean AllowPixelFog
;
126 /** Derived values, invalidated on statechanges, updated from
127 * _swrast_validate_derived():
129 GLbitfield _RasterMask
;
130 GLfloat _BackfaceSign
;
131 GLboolean _PreferPixelFog
; /* Compute fog blend factor per fragment? */
132 GLboolean _AnyTextureCombine
;
133 GLboolean _FogEnabled
;
134 GLenum _FogMode
; /* either GL_FOG_MODE or fragment program's fog mode */
136 /* Accum buffer temporaries.
138 GLboolean _IntegerAccumMode
; /**< Storing unscaled integers? */
139 GLfloat _IntegerAccumScaler
; /**< Implicit scale factor */
143 GLuint StippleCounter
; /**< Line stipple counter */
146 GLenum Primitive
; /* current primitive being drawn (ala glBegin) */
148 void (*InvalidateState
)( GLcontext
*ctx
, GLbitfield new_state
);
151 * When the NewState mask intersects these masks, we invalidate the
152 * Point/Line/Triangle function pointers below.
155 GLbitfield InvalidatePointMask
;
156 GLbitfield InvalidateLineMask
;
157 GLbitfield InvalidateTriangleMask
;
161 * Device drivers plug in functions for these callbacks.
162 * Will be called when the GL state change mask intersects the above masks.
165 void (*choose_point
)( GLcontext
* );
166 void (*choose_line
)( GLcontext
* );
167 void (*choose_triangle
)( GLcontext
* );
171 * Current point, line and triangle drawing functions.
174 swrast_point_func Point
;
175 swrast_line_func Line
;
176 swrast_tri_func Triangle
;
180 * Placeholders for when separate specular (or secondary color) is
181 * enabled but texturing is not.
184 swrast_point_func SpecPoint
;
185 swrast_line_func SpecLine
;
186 swrast_tri_func SpecTriangle
;
190 * Typically, we'll allocate a sw_span structure as a local variable
191 * and set its 'array' pointer to point to this object. The reason is
192 * this object is big and causes problems when allocated on the stack
195 SWspanarrays
*SpanArrays
;
198 * Used to buffer N GL_POINTS, instead of rendering one by one.
202 /** Internal hooks, kept up to date by the same mechanism as above.
204 blend_func BlendFunc
;
205 texture_sample_func TextureSample
[MAX_TEXTURE_IMAGE_UNITS
];
207 /** Buffer for saving the sampled texture colors.
208 * Needed for GL_ARB_texture_env_crossbar implementation.
212 validate_texture_image_func ValidateTextureImage
;
218 _swrast_validate_derived( GLcontext
*ctx
);
221 #define SWRAST_CONTEXT(ctx) ((SWcontext *)ctx->swrast_context)
223 #define RENDER_START(SWctx, GLctx) \
225 if ((SWctx)->Driver.SpanRenderStart) { \
226 (*(SWctx)->Driver.SpanRenderStart)(GLctx); \
230 #define RENDER_FINISH(SWctx, GLctx) \
232 if ((SWctx)->Driver.SpanRenderFinish) { \
233 (*(SWctx)->Driver.SpanRenderFinish)(GLctx); \
240 * Size of an RGBA pixel, in bytes, for given datatype.
242 #define RGBA_PIXEL_SIZE(TYPE) \
243 ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) : \
244 ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort) \
245 : 4 * sizeof(GLfloat)))
250 * XXX these macros are just bandages for now in order to make
251 * CHAN_BITS==32 compile cleanly.
252 * These should probably go elsewhere at some point.
254 #if CHAN_TYPE == GL_FLOAT
255 #define ChanToFixed(X) (X)
256 #define FixedToChan(X) (X)
258 #define ChanToFixed(X) IntToFixed(X)
259 #define FixedToChan(X) FixedToInt(X)