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/compiler.h"
47#include "main/mtypes.h"
48#include "program/prog_execute.h"
49#include "swrast.h"
50#include "s_fragprog.h"
51#include "s_span.h"
52
53
54typedef void (*texture_sample_func)(struct gl_context *ctx,
55                                    const struct gl_sampler_object *samp,
56                                    const struct gl_texture_object *tObj,
57                                    GLuint n, const GLfloat texcoords[][4],
58                                    const GLfloat lambda[], GLfloat rgba[][4]);
59
60typedef void (_ASMAPIP blend_func)( struct gl_context *ctx, GLuint n,
61                                    const GLubyte mask[],
62                                    GLvoid *src, const GLvoid *dst,
63                                    GLenum chanType);
64
65typedef void (*swrast_point_func)( struct gl_context *ctx, const SWvertex *);
66
67typedef void (*swrast_line_func)( struct gl_context *ctx,
68                                  const SWvertex *, const SWvertex *);
69
70typedef void (*swrast_tri_func)( struct gl_context *ctx, const SWvertex *,
71                                 const SWvertex *, const SWvertex *);
72
73
74typedef void (*validate_texture_image_func)(struct gl_context *ctx,
75                                            struct gl_texture_object *texObj,
76                                            GLuint face, GLuint level);
77
78
79/**
80 * \defgroup Bitmasks
81 * Bitmasks to indicate which rasterization options are enabled
82 * (RasterMask)
83 */
84/*@{*/
85#define ALPHATEST_BIT		0x001	/**< Alpha-test pixels */
86#define BLEND_BIT		0x002	/**< Blend pixels */
87#define DEPTH_BIT		0x004	/**< Depth-test pixels */
88#define FOG_BIT			0x008	/**< Fog pixels */
89#define LOGIC_OP_BIT		0x010	/**< Apply logic op in software */
90#define CLIP_BIT		0x020	/**< Scissor or window clip pixels */
91#define STENCIL_BIT		0x040	/**< Stencil pixels */
92#define MASKING_BIT		0x080	/**< Do glColorMask or glIndexMask */
93#define MULTI_DRAW_BIT		0x400	/**< Write to more than one color- */
94                                        /**< buffer or no buffers. */
95#define OCCLUSION_BIT           0x800   /**< GL_HP_occlusion_test enabled */
96#define TEXTURE_BIT		0x1000	/**< Texturing really enabled */
97#define FRAGPROG_BIT            0x2000  /**< Fragment program enabled */
98#define ATIFRAGSHADER_BIT       0x4000  /**< ATI Fragment shader enabled */
99#define CLAMPING_BIT            0x8000  /**< Clamp colors to [0,1] */
100/*@}*/
101
102#define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS|	\
103			        _NEW_SCISSOR|	\
104			        _NEW_COLOR|	\
105			        _NEW_DEPTH|	\
106			        _NEW_FOG|	\
107                                _NEW_PROGRAM|   \
108			        _NEW_STENCIL|	\
109			        _NEW_TEXTURE|	\
110			        _NEW_VIEWPORT|	\
111			        _NEW_DEPTH)
112
113
114struct swrast_texture_image;
115
116
117/**
118 * Fetch a texel from texture image at given position.
119 */
120typedef void (*FetchTexelFunc)(const struct swrast_texture_image *texImage,
121                               GLint col, GLint row, GLint img,
122                               GLfloat *texelOut);
123
124
125/**
126 * Subclass of gl_texture_image.
127 * We need extra fields/info to keep tracking of mapped texture buffers,
128 * strides and Fetch functions.
129 */
130struct swrast_texture_image
131{
132   struct gl_texture_image Base;
133
134   GLboolean _IsPowerOfTwo;  /**< Are all dimensions powers of two? */
135
136   /** used for mipmap LOD computation */
137   GLfloat WidthScale, HeightScale, DepthScale;
138
139   /** These fields only valid when texture memory is mapped */
140   GLint RowStride;		/**< Padded width in units of texels */
141   GLuint *ImageOffsets;        /**< if 3D texture: array [Depth] of offsets to
142                                     each 2D slice in 'Data', in texels */
143   GLubyte *Map;		/**< Pointer to mapped image memory */
144
145   /** Malloc'd texture memory */
146   GLubyte *Buffer;
147
148   FetchTexelFunc FetchTexel;
149};
150
151
152/** cast wrapper */
153static inline struct swrast_texture_image *
154swrast_texture_image(struct gl_texture_image *img)
155{
156   return (struct swrast_texture_image *) img;
157}
158
159/** cast wrapper */
160static inline const struct swrast_texture_image *
161swrast_texture_image_const(const struct gl_texture_image *img)
162{
163   return (const struct swrast_texture_image *) img;
164}
165
166
167/**
168 * Subclass of gl_renderbuffer with extra fields needed for software
169 * rendering.
170 */
171struct swrast_renderbuffer
172{
173   struct gl_renderbuffer Base;
174
175   GLubyte *Buffer;     /**< The malloc'd memory for buffer */
176
177   /** These fields are only valid while buffer is mapped for rendering */
178   GLubyte *Map;
179   GLint RowStride;    /**< in bytes */
180
181   /** For span rendering */
182   GLenum ColorType;
183};
184
185
186/** cast wrapper */
187static inline struct swrast_renderbuffer *
188swrast_renderbuffer(struct gl_renderbuffer *img)
189{
190   return (struct swrast_renderbuffer *) img;
191}
192
193
194
195/**
196 * \struct SWcontext
197 * \brief  Per-context state that's private to the software rasterizer module.
198 */
199typedef struct
200{
201   /** Driver interface:
202    */
203   struct swrast_device_driver Driver;
204
205   /** Configuration mechanisms to make software rasterizer match
206    * characteristics of the hardware rasterizer (if present):
207    */
208   GLboolean AllowVertexFog;
209   GLboolean AllowPixelFog;
210
211   /** Derived values, invalidated on statechanges, updated from
212    * _swrast_validate_derived():
213    */
214   GLbitfield _RasterMask;
215   GLfloat _BackfaceSign;      /** +1 or -1 */
216   GLfloat _BackfaceCullSign;  /** +1, 0, or -1 */
217   GLboolean _PreferPixelFog;    /* Compute fog blend factor per fragment? */
218   GLboolean _TextureCombinePrimary;
219   GLboolean _FogEnabled;
220   GLboolean _DeferredTexture;
221
222   /** List/array of the fragment attributes to interpolate */
223   GLuint _ActiveAttribs[FRAG_ATTRIB_MAX];
224   /** Same info, but as a bitmask of FRAG_BIT_x bits */
225   GLbitfield64 _ActiveAttribMask;
226   /** Number of fragment attributes to interpolate */
227   GLuint _NumActiveAttribs;
228   /** Indicates how each attrib is to be interpolated (lines/tris) */
229   GLenum _InterpMode[FRAG_ATTRIB_MAX]; /* GL_FLAT or GL_SMOOTH (for now) */
230
231   /* Working values:
232    */
233   GLuint StippleCounter;    /**< Line stipple counter */
234   GLuint PointLineFacing;
235   GLbitfield NewState;
236   GLuint StateChanges;
237   GLenum Primitive;    /* current primitive being drawn (ala glBegin) */
238   GLboolean SpecularVertexAdd; /**< Add specular/secondary color per vertex */
239
240   void (*InvalidateState)( struct gl_context *ctx, GLbitfield new_state );
241
242   /**
243    * When the NewState mask intersects these masks, we invalidate the
244    * Point/Line/Triangle function pointers below.
245    */
246   /*@{*/
247   GLbitfield InvalidatePointMask;
248   GLbitfield InvalidateLineMask;
249   GLbitfield InvalidateTriangleMask;
250   /*@}*/
251
252   /**
253    * Device drivers plug in functions for these callbacks.
254    * Will be called when the GL state change mask intersects the above masks.
255    */
256   /*@{*/
257   void (*choose_point)( struct gl_context * );
258   void (*choose_line)( struct gl_context * );
259   void (*choose_triangle)( struct gl_context * );
260   /*@}*/
261
262   /**
263    * Current point, line and triangle drawing functions.
264    */
265   /*@{*/
266   swrast_point_func Point;
267   swrast_line_func Line;
268   swrast_tri_func Triangle;
269   /*@}*/
270
271   /**
272    * Placeholders for when separate specular (or secondary color) is
273    * enabled but texturing is not.
274    */
275   /*@{*/
276   swrast_point_func SpecPoint;
277   swrast_line_func SpecLine;
278   swrast_tri_func SpecTriangle;
279   /*@}*/
280
281   /**
282    * Typically, we'll allocate a sw_span structure as a local variable
283    * and set its 'array' pointer to point to this object.  The reason is
284    * this object is big and causes problems when allocated on the stack
285    * on some systems.
286    */
287   SWspanarrays *SpanArrays;
288   SWspanarrays *ZoomedArrays;  /**< For pixel zooming */
289
290   /**
291    * Used to buffer N GL_POINTS, instead of rendering one by one.
292    */
293   SWspan PointSpan;
294
295   /** Internal hooks, kept up to date by the same mechanism as above.
296    */
297   blend_func BlendFunc;
298   texture_sample_func TextureSample[MAX_TEXTURE_IMAGE_UNITS];
299
300   /** Buffer for saving the sampled texture colors.
301    * Needed for GL_ARB_texture_env_crossbar implementation.
302    */
303   GLfloat *TexelBuffer;
304
305   validate_texture_image_func ValidateTextureImage;
306
307   /** State used during execution of fragment programs */
308   struct gl_program_machine FragProgMachine;
309
310   /** Temporary arrays for stencil operations.  To avoid large stack
311    * allocations.
312    */
313   struct {
314      GLubyte *buf1, *buf2, *buf3, *buf4;
315   } stencil_temp;
316
317} SWcontext;
318
319
320extern void
321_swrast_validate_derived( struct gl_context *ctx );
322
323extern void
324_swrast_update_texture_samplers(struct gl_context *ctx);
325
326
327/** Return SWcontext for the given struct gl_context */
328static inline SWcontext *
329SWRAST_CONTEXT(struct gl_context *ctx)
330{
331   return (SWcontext *) ctx->swrast_context;
332}
333
334/** const version of above */
335static inline const SWcontext *
336CONST_SWRAST_CONTEXT(const struct gl_context *ctx)
337{
338   return (const SWcontext *) ctx->swrast_context;
339}
340
341
342/**
343 * Called prior to framebuffer reading/writing.
344 * For drivers that rely on swrast for fallback rendering, this is the
345 * driver's opportunity to map renderbuffers and textures.
346 */
347static inline void
348swrast_render_start(struct gl_context *ctx)
349{
350   SWcontext *swrast = SWRAST_CONTEXT(ctx);
351   if (swrast->Driver.SpanRenderStart)
352      swrast->Driver.SpanRenderStart(ctx);
353}
354
355
356/** Called after framebuffer reading/writing */
357static inline void
358swrast_render_finish(struct gl_context *ctx)
359{
360   SWcontext *swrast = SWRAST_CONTEXT(ctx);
361   if (swrast->Driver.SpanRenderFinish)
362      swrast->Driver.SpanRenderFinish(ctx);
363}
364
365
366extern void
367_swrast_span_render_start(struct gl_context *ctx);
368
369extern void
370_swrast_span_render_finish(struct gl_context *ctx);
371
372extern void
373_swrast_map_textures(struct gl_context *ctx);
374
375extern void
376_swrast_unmap_textures(struct gl_context *ctx);
377
378extern void
379_swrast_map_texture(struct gl_context *ctx, struct gl_texture_object *texObj);
380
381extern void
382_swrast_unmap_texture(struct gl_context *ctx, struct gl_texture_object *texObj);
383
384
385extern void
386_swrast_map_renderbuffers(struct gl_context *ctx);
387
388extern void
389_swrast_unmap_renderbuffers(struct gl_context *ctx);
390
391
392/**
393 * Size of an RGBA pixel, in bytes, for given datatype.
394 */
395#define RGBA_PIXEL_SIZE(TYPE)                                     \
396         ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) :      \
397          ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort)     \
398           : 4 * sizeof(GLfloat)))
399
400
401
402/*
403 * Fixed point arithmetic macros
404 */
405#ifndef FIXED_FRAC_BITS
406#define FIXED_FRAC_BITS 11
407#endif
408
409#define FIXED_SHIFT     FIXED_FRAC_BITS
410#define FIXED_ONE       (1 << FIXED_SHIFT)
411#define FIXED_HALF      (1 << (FIXED_SHIFT-1))
412#define FIXED_FRAC_MASK (FIXED_ONE - 1)
413#define FIXED_INT_MASK  (~FIXED_FRAC_MASK)
414#define FIXED_EPSILON   1
415#define FIXED_SCALE     ((float) FIXED_ONE)
416#define FIXED_DBL_SCALE ((double) FIXED_ONE)
417#define FloatToFixed(X) (IROUND((X) * FIXED_SCALE))
418#define FixedToDouble(X) ((X) * (1.0 / FIXED_DBL_SCALE))
419#define IntToFixed(I)   ((I) << FIXED_SHIFT)
420#define FixedToInt(X)   ((X) >> FIXED_SHIFT)
421#define FixedToUns(X)   (((unsigned int)(X)) >> FIXED_SHIFT)
422#define FixedCeil(X)    (((X) + FIXED_ONE - FIXED_EPSILON) & FIXED_INT_MASK)
423#define FixedFloor(X)   ((X) & FIXED_INT_MASK)
424#define FixedToFloat(X) ((X) * (1.0F / FIXED_SCALE))
425#define PosFloatToFixed(X)      FloatToFixed(X)
426#define SignedFloatToFixed(X)   FloatToFixed(X)
427
428
429
430/*
431 * XXX these macros are just bandages for now in order to make
432 * CHAN_BITS==32 compile cleanly.
433 * These should probably go elsewhere at some point.
434 */
435#if CHAN_TYPE == GL_FLOAT
436#define ChanToFixed(X)  (X)
437#define FixedToChan(X)  (X)
438#else
439#define ChanToFixed(X)  IntToFixed(X)
440#define FixedToChan(X)  FixedToInt(X)
441#endif
442
443
444/**
445 * For looping over fragment attributes in the pointe, line
446 * triangle rasterizers.
447 */
448#define ATTRIB_LOOP_BEGIN                                \
449   {                                                     \
450      GLuint a;                                          \
451      for (a = 0; a < swrast->_NumActiveAttribs; a++) {  \
452         const GLuint attr = swrast->_ActiveAttribs[a];
453
454#define ATTRIB_LOOP_END } }
455
456
457/**
458 * Return the address of a pixel value in a mapped renderbuffer.
459 */
460static inline GLubyte *
461_swrast_pixel_address(struct gl_renderbuffer *rb, GLint x, GLint y)
462{
463   struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
464   const GLint bpp = _mesa_get_format_bytes(rb->Format);
465   const GLint rowStride = srb->RowStride;
466   assert(x >= 0);
467   assert(y >= 0);
468   /* NOTE: using <= only because of s_tritemp.h which gets a pixel
469    * address but doesn't necessarily access it.
470    */
471   assert(x <= (GLint) rb->Width);
472   assert(y <= (GLint) rb->Height);
473   assert(srb->Map);
474   return (GLubyte *) srb->Map + y * rowStride + x * bpp;
475}
476
477
478
479#endif
480