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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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/compiler.h"
47 #include "main/mtypes.h"
48 #include "program/prog_execute.h"
53 typedef void (*texture_sample_func
)(struct gl_context
*ctx
,
54 const struct gl_texture_object
*tObj
,
55 GLuint n
, const GLfloat texcoords
[][4],
56 const GLfloat lambda
[], GLfloat rgba
[][4]);
58 typedef void (_ASMAPIP blend_func
)( struct gl_context
*ctx
, GLuint n
,
60 GLvoid
*src
, const GLvoid
*dst
,
63 typedef void (*swrast_point_func
)( struct gl_context
*ctx
, const SWvertex
*);
65 typedef void (*swrast_line_func
)( struct gl_context
*ctx
,
66 const SWvertex
*, const SWvertex
*);
68 typedef void (*swrast_tri_func
)( struct gl_context
*ctx
, const SWvertex
*,
69 const SWvertex
*, const SWvertex
*);
72 typedef void (*validate_texture_image_func
)(struct gl_context
*ctx
,
73 struct gl_texture_object
*texObj
,
74 GLuint face
, GLuint level
);
79 * Bitmasks to indicate which rasterization options are enabled
83 #define ALPHATEST_BIT 0x001 /**< Alpha-test pixels */
84 #define BLEND_BIT 0x002 /**< Blend pixels */
85 #define DEPTH_BIT 0x004 /**< Depth-test pixels */
86 #define FOG_BIT 0x008 /**< Fog pixels */
87 #define LOGIC_OP_BIT 0x010 /**< Apply logic op in software */
88 #define CLIP_BIT 0x020 /**< Scissor or window clip pixels */
89 #define STENCIL_BIT 0x040 /**< Stencil pixels */
90 #define MASKING_BIT 0x080 /**< Do glColorMask or glIndexMask */
91 #define MULTI_DRAW_BIT 0x400 /**< Write to more than one color- */
92 /**< buffer or no buffers. */
93 #define OCCLUSION_BIT 0x800 /**< GL_HP_occlusion_test enabled */
94 #define TEXTURE_BIT 0x1000 /**< Texturing really enabled */
95 #define FRAGPROG_BIT 0x2000 /**< Fragment program enabled */
96 #define ATIFRAGSHADER_BIT 0x4000 /**< ATI Fragment shader enabled */
97 #define CLAMPING_BIT 0x8000 /**< Clamp colors to [0,1] */
100 #define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS| \
113 * Subclass of gl_texture_image.
114 * We need extra fields/info to keep tracking of mapped texture buffers,
115 * strides and Fetch/Store functions.
117 struct swrast_texture_image
119 struct gl_texture_image Base
;
121 /* XXX new members coming soon */
126 static INLINE
struct swrast_texture_image
*
127 swrast_texture_image(struct gl_texture_image
*img
)
129 return (struct swrast_texture_image
*) img
;
133 static INLINE
const struct swrast_texture_image
*
134 swrast_texture_image_const(const struct gl_texture_image
*img
)
136 return (const struct swrast_texture_image
*) img
;
143 * \brief Per-context state that's private to the software rasterizer module.
147 /** Driver interface:
149 struct swrast_device_driver Driver
;
151 /** Configuration mechanisms to make software rasterizer match
152 * characteristics of the hardware rasterizer (if present):
154 GLboolean AllowVertexFog
;
155 GLboolean AllowPixelFog
;
157 /** Derived values, invalidated on statechanges, updated from
158 * _swrast_validate_derived():
160 GLbitfield _RasterMask
;
161 GLfloat _BackfaceSign
; /** +1 or -1 */
162 GLfloat _BackfaceCullSign
; /** +1, 0, or -1 */
163 GLboolean _PreferPixelFog
; /* Compute fog blend factor per fragment? */
164 GLboolean _TextureCombinePrimary
;
165 GLboolean _FogEnabled
;
166 GLboolean _DeferredTexture
;
168 /** List/array of the fragment attributes to interpolate */
169 GLuint _ActiveAttribs
[FRAG_ATTRIB_MAX
];
170 /** Same info, but as a bitmask */
171 GLbitfield _ActiveAttribMask
;
172 /** Number of fragment attributes to interpolate */
173 GLuint _NumActiveAttribs
;
174 /** Indicates how each attrib is to be interpolated (lines/tris) */
175 GLenum _InterpMode
[FRAG_ATTRIB_MAX
]; /* GL_FLAT or GL_SMOOTH (for now) */
177 /* Accum buffer temporaries.
179 GLboolean _IntegerAccumMode
; /**< Storing unscaled integers? */
180 GLfloat _IntegerAccumScaler
; /**< Implicit scale factor */
184 GLuint StippleCounter
; /**< Line stipple counter */
185 GLuint PointLineFacing
;
188 GLenum Primitive
; /* current primitive being drawn (ala glBegin) */
189 GLboolean SpecularVertexAdd
; /**< Add specular/secondary color per vertex */
191 void (*InvalidateState
)( struct gl_context
*ctx
, GLbitfield new_state
);
194 * When the NewState mask intersects these masks, we invalidate the
195 * Point/Line/Triangle function pointers below.
198 GLbitfield InvalidatePointMask
;
199 GLbitfield InvalidateLineMask
;
200 GLbitfield InvalidateTriangleMask
;
204 * Device drivers plug in functions for these callbacks.
205 * Will be called when the GL state change mask intersects the above masks.
208 void (*choose_point
)( struct gl_context
* );
209 void (*choose_line
)( struct gl_context
* );
210 void (*choose_triangle
)( struct gl_context
* );
214 * Current point, line and triangle drawing functions.
217 swrast_point_func Point
;
218 swrast_line_func Line
;
219 swrast_tri_func Triangle
;
223 * Placeholders for when separate specular (or secondary color) is
224 * enabled but texturing is not.
227 swrast_point_func SpecPoint
;
228 swrast_line_func SpecLine
;
229 swrast_tri_func SpecTriangle
;
233 * Typically, we'll allocate a sw_span structure as a local variable
234 * and set its 'array' pointer to point to this object. The reason is
235 * this object is big and causes problems when allocated on the stack
238 SWspanarrays
*SpanArrays
;
239 SWspanarrays
*ZoomedArrays
; /**< For pixel zooming */
242 * Used to buffer N GL_POINTS, instead of rendering one by one.
246 /** Internal hooks, kept up to date by the same mechanism as above.
248 blend_func BlendFunc
;
249 texture_sample_func TextureSample
[MAX_TEXTURE_IMAGE_UNITS
];
251 /** Buffer for saving the sampled texture colors.
252 * Needed for GL_ARB_texture_env_crossbar implementation.
254 GLfloat
*TexelBuffer
;
256 validate_texture_image_func ValidateTextureImage
;
258 /** State used during execution of fragment programs */
259 struct gl_program_machine FragProgMachine
;
265 _swrast_validate_derived( struct gl_context
*ctx
);
268 _swrast_update_texture_samplers(struct gl_context
*ctx
);
271 /** Return SWcontext for the given struct gl_context */
272 static INLINE SWcontext
*
273 SWRAST_CONTEXT(struct gl_context
*ctx
)
275 return (SWcontext
*) ctx
->swrast_context
;
278 /** const version of above */
279 static INLINE
const SWcontext
*
280 CONST_SWRAST_CONTEXT(const struct gl_context
*ctx
)
282 return (const SWcontext
*) ctx
->swrast_context
;
287 * Called prior to framebuffer reading/writing.
288 * For drivers that rely on swrast for fallback rendering, this is the
289 * driver's opportunity to map renderbuffers and textures.
292 swrast_render_start(struct gl_context
*ctx
)
294 SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
295 if (swrast
->Driver
.SpanRenderStart
)
296 swrast
->Driver
.SpanRenderStart(ctx
);
300 /** Called after framebuffer reading/writing */
302 swrast_render_finish(struct gl_context
*ctx
)
304 SWcontext
*swrast
= SWRAST_CONTEXT(ctx
);
305 if (swrast
->Driver
.SpanRenderFinish
)
306 swrast
->Driver
.SpanRenderFinish(ctx
);
312 * Size of an RGBA pixel, in bytes, for given datatype.
314 #define RGBA_PIXEL_SIZE(TYPE) \
315 ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) : \
316 ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort) \
317 : 4 * sizeof(GLfloat)))
322 * Fixed point arithmetic macros
324 #ifndef FIXED_FRAC_BITS
325 #define FIXED_FRAC_BITS 11
328 #define FIXED_SHIFT FIXED_FRAC_BITS
329 #define FIXED_ONE (1 << FIXED_SHIFT)
330 #define FIXED_HALF (1 << (FIXED_SHIFT-1))
331 #define FIXED_FRAC_MASK (FIXED_ONE - 1)
332 #define FIXED_INT_MASK (~FIXED_FRAC_MASK)
333 #define FIXED_EPSILON 1
334 #define FIXED_SCALE ((float) FIXED_ONE)
335 #define FIXED_DBL_SCALE ((double) FIXED_ONE)
336 #define FloatToFixed(X) (IROUND((X) * FIXED_SCALE))
337 #define FixedToDouble(X) ((X) * (1.0 / FIXED_DBL_SCALE))
338 #define IntToFixed(I) ((I) << FIXED_SHIFT)
339 #define FixedToInt(X) ((X) >> FIXED_SHIFT)
340 #define FixedToUns(X) (((unsigned int)(X)) >> FIXED_SHIFT)
341 #define FixedCeil(X) (((X) + FIXED_ONE - FIXED_EPSILON) & FIXED_INT_MASK)
342 #define FixedFloor(X) ((X) & FIXED_INT_MASK)
343 #define FixedToFloat(X) ((X) * (1.0F / FIXED_SCALE))
344 #define PosFloatToFixed(X) FloatToFixed(X)
345 #define SignedFloatToFixed(X) FloatToFixed(X)
350 * XXX these macros are just bandages for now in order to make
351 * CHAN_BITS==32 compile cleanly.
352 * These should probably go elsewhere at some point.
354 #if CHAN_TYPE == GL_FLOAT
355 #define ChanToFixed(X) (X)
356 #define FixedToChan(X) (X)
358 #define ChanToFixed(X) IntToFixed(X)
359 #define FixedToChan(X) FixedToInt(X)
364 * For looping over fragment attributes in the pointe, line
365 * triangle rasterizers.
367 #define ATTRIB_LOOP_BEGIN \
370 for (a = 0; a < swrast->_NumActiveAttribs; a++) { \
371 const GLuint attr = swrast->_ActiveAttribs[a];
373 #define ATTRIB_LOOP_END } }