s_context.h revision 4a49301e 
1/*
2 * Mesa 3-D graphics library
3 * Version:  6.5.3
4 *
5 * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
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:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
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
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26/**
27 * \file swrast/s_context.h
28 * \brief Software rasterization context and private types.
29 * \author Keith Whitwell <keith@tungstengraphics.com>
30 */
31
32/**
33 * \mainpage swrast module
34 *
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.
40 */
41
42
43#ifndef S_CONTEXT_H
44#define S_CONTEXT_H
45
46#include "main/mtypes.h"
47#include "shader/prog_execute.h"
48#include "swrast.h"
49#include "s_span.h"
50
51
52typedef void (*texture_sample_func)(GLcontext *ctx,
53                                    const struct gl_texture_object *tObj,
54                                    GLuint n, const GLfloat texcoords[][4],
55                                    const GLfloat lambda[], GLfloat rgba[][4]);
56
57typedef void (_ASMAPIP blend_func)( GLcontext *ctx, GLuint n,
58                                    const GLubyte mask[],
59                                    GLvoid *src, const GLvoid *dst,
60                                    GLenum chanType);
61
62typedef void (*swrast_point_func)( GLcontext *ctx, const SWvertex *);
63
64typedef void (*swrast_line_func)( GLcontext *ctx,
65                                  const SWvertex *, const SWvertex *);
66
67typedef void (*swrast_tri_func)( GLcontext *ctx, const SWvertex *,
68                                 const SWvertex *, const SWvertex *);
69
70
71typedef void (*validate_texture_image_func)(GLcontext *ctx,
72                                            struct gl_texture_object *texObj,
73                                            GLuint face, GLuint level);
74
75
76/**
77 * \defgroup Bitmasks
78 * Bitmasks to indicate which rasterization options are enabled
79 * (RasterMask)
80 */
81/*@{*/
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] */
97/*@}*/
98
99#define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS|	\
100			        _NEW_SCISSOR|	\
101			        _NEW_COLOR|	\
102			        _NEW_DEPTH|	\
103			        _NEW_FOG|	\
104                                _NEW_PROGRAM|   \
105			        _NEW_STENCIL|	\
106			        _NEW_TEXTURE|	\
107			        _NEW_VIEWPORT|	\
108			        _NEW_DEPTH)
109
110
111/**
112 * \struct SWcontext
113 * \brief  Per-context state that's private to the software rasterizer module.
114 */
115typedef struct
116{
117   /** Driver interface:
118    */
119   struct swrast_device_driver Driver;
120
121   /** Configuration mechanisms to make software rasterizer match
122    * characteristics of the hardware rasterizer (if present):
123    */
124   GLboolean AllowVertexFog;
125   GLboolean AllowPixelFog;
126
127   /** Derived values, invalidated on statechanges, updated from
128    * _swrast_validate_derived():
129    */
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 _TextureCombinePrimary;
135   GLboolean _FogEnabled;
136   GLboolean _DeferredTexture;
137   GLenum _FogMode;  /* either GL_FOG_MODE or fragment program's fog mode */
138
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) */
147
148   /* Accum buffer temporaries.
149    */
150   GLboolean _IntegerAccumMode;	/**< Storing unscaled integers? */
151   GLfloat _IntegerAccumScaler;	/**< Implicit scale factor */
152
153   /* Working values:
154    */
155   GLuint StippleCounter;    /**< Line stipple counter */
156   GLuint PointLineFacing;
157   GLbitfield NewState;
158   GLuint StateChanges;
159   GLenum Primitive;    /* current primitive being drawn (ala glBegin) */
160   GLboolean SpecularVertexAdd; /**< Add specular/secondary color per vertex */
161
162   void (*InvalidateState)( GLcontext *ctx, GLbitfield new_state );
163
164   /**
165    * When the NewState mask intersects these masks, we invalidate the
166    * Point/Line/Triangle function pointers below.
167    */
168   /*@{*/
169   GLbitfield InvalidatePointMask;
170   GLbitfield InvalidateLineMask;
171   GLbitfield InvalidateTriangleMask;
172   /*@}*/
173
174   /**
175    * Device drivers plug in functions for these callbacks.
176    * Will be called when the GL state change mask intersects the above masks.
177    */
178   /*@{*/
179   void (*choose_point)( GLcontext * );
180   void (*choose_line)( GLcontext * );
181   void (*choose_triangle)( GLcontext * );
182   /*@}*/
183
184   /**
185    * Current point, line and triangle drawing functions.
186    */
187   /*@{*/
188   swrast_point_func Point;
189   swrast_line_func Line;
190   swrast_tri_func Triangle;
191   /*@}*/
192
193   /**
194    * Placeholders for when separate specular (or secondary color) is
195    * enabled but texturing is not.
196    */
197   /*@{*/
198   swrast_point_func SpecPoint;
199   swrast_line_func SpecLine;
200   swrast_tri_func SpecTriangle;
201   /*@}*/
202
203   /**
204    * Typically, we'll allocate a sw_span structure as a local variable
205    * and set its 'array' pointer to point to this object.  The reason is
206    * this object is big and causes problems when allocated on the stack
207    * on some systems.
208    */
209   SWspanarrays *SpanArrays;
210   SWspanarrays *ZoomedArrays;  /**< For pixel zooming */
211
212   /**
213    * Used to buffer N GL_POINTS, instead of rendering one by one.
214    */
215   SWspan PointSpan;
216
217   /** Internal hooks, kept up to date by the same mechanism as above.
218    */
219   blend_func BlendFunc;
220   texture_sample_func TextureSample[MAX_TEXTURE_IMAGE_UNITS];
221
222   /** Buffer for saving the sampled texture colors.
223    * Needed for GL_ARB_texture_env_crossbar implementation.
224    */
225   GLfloat *TexelBuffer;
226
227   validate_texture_image_func ValidateTextureImage;
228
229   /** State used during execution of fragment programs */
230   struct gl_program_machine FragProgMachine;
231
232} SWcontext;
233
234
235extern void
236_swrast_validate_derived( GLcontext *ctx );
237
238extern void
239_swrast_update_texture_samplers(GLcontext *ctx);
240
241
242/** Return SWcontext for the given GLcontext */
243static INLINE SWcontext *
244SWRAST_CONTEXT(GLcontext *ctx)
245{
246   return (SWcontext *) ctx->swrast_context;
247}
248
249/** const version of above */
250static INLINE const SWcontext *
251CONST_SWRAST_CONTEXT(const GLcontext *ctx)
252{
253   return (const SWcontext *) ctx->swrast_context;
254}
255
256
257/**
258 * Called prior to framebuffer reading/writing.
259 * For drivers that rely on swrast for fallback rendering, this is the
260 * driver's opportunity to map renderbuffers and textures.
261 */
262static INLINE void
263swrast_render_start(GLcontext *ctx)
264{
265   SWcontext *swrast = SWRAST_CONTEXT(ctx);
266   if (swrast->Driver.SpanRenderStart)
267      swrast->Driver.SpanRenderStart(ctx);
268}
269
270
271/** Called after framebuffer reading/writing */
272static INLINE void
273swrast_render_finish(GLcontext *ctx)
274{
275   SWcontext *swrast = SWRAST_CONTEXT(ctx);
276   if (swrast->Driver.SpanRenderFinish)
277      swrast->Driver.SpanRenderFinish(ctx);
278}
279
280
281
282/**
283 * Size of an RGBA pixel, in bytes, for given datatype.
284 */
285#define RGBA_PIXEL_SIZE(TYPE)                                     \
286         ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) :      \
287          ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort)     \
288           : 4 * sizeof(GLfloat)))
289
290
291
292/*
293 * Fixed point arithmetic macros
294 */
295#ifndef FIXED_FRAC_BITS
296#define FIXED_FRAC_BITS 11
297#endif
298
299#define FIXED_SHIFT     FIXED_FRAC_BITS
300#define FIXED_ONE       (1 << FIXED_SHIFT)
301#define FIXED_HALF      (1 << (FIXED_SHIFT-1))
302#define FIXED_FRAC_MASK (FIXED_ONE - 1)
303#define FIXED_INT_MASK  (~FIXED_FRAC_MASK)
304#define FIXED_EPSILON   1
305#define FIXED_SCALE     ((float) FIXED_ONE)
306#define FIXED_DBL_SCALE ((double) FIXED_ONE)
307#define FloatToFixed(X) (IROUND((X) * FIXED_SCALE))
308#define FixedToDouble(X) ((X) * (1.0 / FIXED_DBL_SCALE))
309#define IntToFixed(I)   ((I) << FIXED_SHIFT)
310#define FixedToInt(X)   ((X) >> FIXED_SHIFT)
311#define FixedToUns(X)   (((unsigned int)(X)) >> FIXED_SHIFT)
312#define FixedCeil(X)    (((X) + FIXED_ONE - FIXED_EPSILON) & FIXED_INT_MASK)
313#define FixedFloor(X)   ((X) & FIXED_INT_MASK)
314#define FixedToFloat(X) ((X) * (1.0F / FIXED_SCALE))
315#define PosFloatToFixed(X)      FloatToFixed(X)
316#define SignedFloatToFixed(X)   FloatToFixed(X)
317
318
319
320/*
321 * XXX these macros are just bandages for now in order to make
322 * CHAN_BITS==32 compile cleanly.
323 * These should probably go elsewhere at some point.
324 */
325#if CHAN_TYPE == GL_FLOAT
326#define ChanToFixed(X)  (X)
327#define FixedToChan(X)  (X)
328#else
329#define ChanToFixed(X)  IntToFixed(X)
330#define FixedToChan(X)  FixedToInt(X)
331#endif
332
333
334/**
335 * For looping over fragment attributes in the pointe, line
336 * triangle rasterizers.
337 */
338#define ATTRIB_LOOP_BEGIN                                \
339   {                                                     \
340      GLuint a;                                          \
341      for (a = 0; a < swrast->_NumActiveAttribs; a++) {  \
342         const GLuint attr = swrast->_ActiveAttribs[a];
343
344#define ATTRIB_LOOP_END } }
345
346
347
348#endif
349