2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
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8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
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11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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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.
46 #include "main/mtypes.h"
47 #include "shader/prog_execute.h"
52 typedef void (*texture_sample_func
)(GLcontext
*ctx
,
53 const struct gl_texture_object
*tObj
,
54 GLuint n
, const GLfloat texcoords
[][4],
55 const GLfloat lambda
[], GLchan rgba
[][4]);
57 typedef void (_ASMAPIP blend_func
)( GLcontext
*ctx
, GLuint n
,
59 GLvoid
*src
, const GLvoid
*dst
,
62 typedef void (*swrast_point_func
)( GLcontext
*ctx
, const SWvertex
*);
64 typedef void (*swrast_line_func
)( GLcontext
*ctx
,
65 const SWvertex
*, const SWvertex
*);
67 typedef void (*swrast_tri_func
)( GLcontext
*ctx
, const SWvertex
*,
68 const SWvertex
*, const SWvertex
*);
71 typedef void (*validate_texture_image_func
)(GLcontext
*ctx
,
72 struct gl_texture_object
*texObj
,
73 GLuint face
, GLuint level
);
78 * Bitmasks to indicate which rasterization options are enabled
82 #define ALPHATEST_BIT 0x001 /**< Alpha-test pixels */
83 #define BLEND_BIT 0x002 /**< Blend pixels */
84 #define DEPTH_BIT 0x004 /**< Depth-test pixels */
85 #define FOG_BIT 0x008 /**< Fog pixels */
86 #define LOGIC_OP_BIT 0x010 /**< Apply logic op in software */
87 #define CLIP_BIT 0x020 /**< Scissor or window clip pixels */
88 #define STENCIL_BIT 0x040 /**< Stencil pixels */
89 #define MASKING_BIT 0x080 /**< Do glColorMask or glIndexMask */
90 #define MULTI_DRAW_BIT 0x400 /**< Write to more than one color- */
91 /**< buffer or no buffers. */
92 #define OCCLUSION_BIT 0x800 /**< GL_HP_occlusion_test enabled */
93 #define TEXTURE_BIT 0x1000 /**< Texturing really enabled */
94 #define FRAGPROG_BIT 0x2000 /**< Fragment program enabled */
95 #define ATIFRAGSHADER_BIT 0x4000 /**< ATI Fragment shader enabled */
96 #define CLAMPING_BIT 0x8000 /**< Clamp colors to [0,1] */
99 #define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS| \
113 * \brief Per-context state that's private to the software rasterizer module.
117 /** Driver interface:
119 struct swrast_device_driver Driver
;
121 /** Configuration mechanisms to make software rasterizer match
122 * characteristics of the hardware rasterizer (if present):
124 GLboolean AllowVertexFog
;
125 GLboolean AllowPixelFog
;
127 /** Derived values, invalidated on statechanges, updated from
128 * _swrast_validate_derived():
130 GLbitfield _RasterMask
;
131 GLfloat _BackfaceSign
; /** +1 or -1 */
132 GLfloat _BackfaceCullSign
; /** +1, 0, or -1 */
133 GLboolean _PreferPixelFog
; /* Compute fog blend factor per fragment? */
134 GLboolean _AnyTextureCombine
;
135 GLboolean _FogEnabled
;
136 GLboolean _DeferredTexture
;
137 GLenum _FogMode
; /* either GL_FOG_MODE or fragment program's fog mode */
139 /** List/array of the fragment attributes to interpolate */
140 GLuint _ActiveAttribs
[FRAG_ATTRIB_MAX
];
141 /** Same info, but as a bitmask */
142 GLbitfield _ActiveAttribMask
;
143 /** Number of fragment attributes to interpolate */
144 GLuint _NumActiveAttribs
;
145 /** Indicates how each attrib is to be interpolated (lines/tris) */
146 GLenum _InterpMode
[FRAG_ATTRIB_MAX
]; /* GL_FLAT or GL_SMOOTH (for now) */
148 /* Accum buffer temporaries.
150 GLboolean _IntegerAccumMode
; /**< Storing unscaled integers? */
151 GLfloat _IntegerAccumScaler
; /**< Implicit scale factor */
155 GLuint StippleCounter
; /**< Line stipple counter */
156 GLuint PointLineFacing
;
159 GLenum Primitive
; /* current primitive being drawn (ala glBegin) */
161 void (*InvalidateState
)( GLcontext
*ctx
, GLbitfield new_state
);
164 * When the NewState mask intersects these masks, we invalidate the
165 * Point/Line/Triangle function pointers below.
168 GLbitfield InvalidatePointMask
;
169 GLbitfield InvalidateLineMask
;
170 GLbitfield InvalidateTriangleMask
;
174 * Device drivers plug in functions for these callbacks.
175 * Will be called when the GL state change mask intersects the above masks.
178 void (*choose_point
)( GLcontext
* );
179 void (*choose_line
)( GLcontext
* );
180 void (*choose_triangle
)( GLcontext
* );
184 * Current point, line and triangle drawing functions.
187 swrast_point_func Point
;
188 swrast_line_func Line
;
189 swrast_tri_func Triangle
;
193 * Placeholders for when separate specular (or secondary color) is
194 * enabled but texturing is not.
197 swrast_point_func SpecPoint
;
198 swrast_line_func SpecLine
;
199 swrast_tri_func SpecTriangle
;
203 * Typically, we'll allocate a sw_span structure as a local variable
204 * and set its 'array' pointer to point to this object. The reason is
205 * this object is big and causes problems when allocated on the stack
208 SWspanarrays
*SpanArrays
;
209 SWspanarrays
*ZoomedArrays
; /**< For pixel zooming */
212 * Used to buffer N GL_POINTS, instead of rendering one by one.
216 /** Internal hooks, kept up to date by the same mechanism as above.
218 blend_func BlendFunc
;
219 texture_sample_func TextureSample
[MAX_TEXTURE_IMAGE_UNITS
];
221 /** Buffer for saving the sampled texture colors.
222 * Needed for GL_ARB_texture_env_crossbar implementation.
226 validate_texture_image_func ValidateTextureImage
;
228 /** State used during execution of fragment programs */
229 struct gl_program_machine FragProgMachine
;
235 _swrast_validate_derived( GLcontext
*ctx
);
238 _swrast_update_texture_samplers(GLcontext
*ctx
);
241 #define SWRAST_CONTEXT(ctx) ((SWcontext *)ctx->swrast_context)
243 #define RENDER_START(SWctx, GLctx) \
245 if ((SWctx)->Driver.SpanRenderStart) { \
246 (*(SWctx)->Driver.SpanRenderStart)(GLctx); \
250 #define RENDER_FINISH(SWctx, GLctx) \
252 if ((SWctx)->Driver.SpanRenderFinish) { \
253 (*(SWctx)->Driver.SpanRenderFinish)(GLctx); \
260 * Size of an RGBA pixel, in bytes, for given datatype.
262 #define RGBA_PIXEL_SIZE(TYPE) \
263 ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) : \
264 ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort) \
265 : 4 * sizeof(GLfloat)))
270 * XXX these macros are just bandages for now in order to make
271 * CHAN_BITS==32 compile cleanly.
272 * These should probably go elsewhere at some point.
274 #if CHAN_TYPE == GL_FLOAT
275 #define ChanToFixed(X) (X)
276 #define FixedToChan(X) (X)
278 #define ChanToFixed(X) IntToFixed(X)
279 #define FixedToChan(X) FixedToInt(X)
284 * For looping over fragment attributes in the pointe, line
285 * triangle rasterizers.
287 #define ATTRIB_LOOP_BEGIN \
290 for (a = 0; a < swrast->_NumActiveAttribs; a++) { \
291 const GLuint attr = swrast->_ActiveAttribs[a];
293 #define ATTRIB_LOOP_END } }