src/mesa/swrast/s_context.h

   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_span.h"
  51
  52
  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]);
  57
  58 typedef void (_ASMAPIP blend_func)( struct gl_context *ctx, GLuint n,
  59                                     const GLubyte mask[],
  60                                     GLvoid *src, const GLvoid *dst,
  61                                     GLenum chanType);
  62
  63 typedef void (*swrast_point_func)( struct gl_context *ctx, const SWvertex *);
  64
  65 typedef void (*swrast_line_func)( struct gl_context *ctx,
  66                                   const SWvertex *, const SWvertex *);
  67
  68 typedef void (*swrast_tri_func)( struct gl_context *ctx, const SWvertex *,
  69                                  const SWvertex *, const SWvertex *);
  70
  71
  72 typedef void (*validate_texture_image_func)(struct gl_context *ctx,
  73                                             struct gl_texture_object *texObj,
  74                                             GLuint face, GLuint level);
  75
  76
  77 /**
  78  * \defgroup Bitmasks
  79  * Bitmasks to indicate which rasterization options are enabled
  80  * (RasterMask)
  81  */
  82 /*@{*/
  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] */
  98 /*@}*/
  99
 100 #define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS|   \
 101                                 _NEW_SCISSOR|   \
 102                                 _NEW_COLOR|     \
 103                                 _NEW_DEPTH|     \
 104                                 _NEW_FOG|       \
 105                                 _NEW_PROGRAM|   \
 106                                 _NEW_STENCIL|   \
 107                                 _NEW_TEXTURE|   \
 108                                 _NEW_VIEWPORT|  \
 109                                 _NEW_DEPTH)
 110
 111
 112 struct swrast_texture_image;
 113
 114
 115 /**
 116  * Fetch a texel from texture image at given position.
 117  */
 118 typedef void (*FetchTexelFunc)(const struct swrast_texture_image *texImage,
 119                                GLint col, GLint row, GLint img,
 120                                GLfloat *texelOut);
 121
 122
 123 typedef void (*StoreTexelFunc)(struct swrast_texture_image *texImage,
 124                                GLint col, GLint row, GLint img,
 125                                const void *texel);
 126
 127 /**
 128  * Subclass of gl_texture_image.
 129  * We need extra fields/info to keep tracking of mapped texture buffers,
 130  * strides and Fetch/Store functions.
 131  */
 132 struct swrast_texture_image
 133 {
 134    struct gl_texture_image Base;
 135
 136    GLboolean _IsPowerOfTwo;  /**< Are all dimensions powers of two? */
 137
 138    /** used for mipmap LOD computation */
 139    GLfloat WidthScale, HeightScale, DepthScale;
 140
 141 #if 0
 142    GLubyte *Data;    /**< The actual texture data in malloc'd memory */
 143
 144    GLint TexelSize;  /**< bytes per texel block */
 145 #endif
 146
 147    FetchTexelFunc FetchTexel;
 148    StoreTexelFunc Store;
 149
 150 #if 0
 151    /** These fields only valid when texture memory is mapped */
 152    GLubyte **SliceMaps;  /**< points to OneMap or a malloc'd array */
 153    GLint RowStride;  /**< bytes per row of blocks */
 154 #endif
 155 };
 156
 157
 158 /** cast wrapper */
 159 static inline struct swrast_texture_image *
 160 swrast_texture_image(struct gl_texture_image *img)
 161 {
 162    return (struct swrast_texture_image *) img;
 163 }
 164
 165 /** cast wrapper */
 166 static inline const struct swrast_texture_image *
 167 swrast_texture_image_const(const struct gl_texture_image *img)
 168 {
 169    return (const struct swrast_texture_image *) img;
 170 }
 171
 172
 173 /**
 174  * \struct SWcontext
 175  * \brief  Per-context state that's private to the software rasterizer module.
 176  */
 177 typedef struct
 178 {
 179    /** Driver interface:
 180     */
 181    struct swrast_device_driver Driver;
 182
 183    /** Configuration mechanisms to make software rasterizer match
 184     * characteristics of the hardware rasterizer (if present):
 185     */
 186    GLboolean AllowVertexFog;
 187    GLboolean AllowPixelFog;
 188
 189    /** Derived values, invalidated on statechanges, updated from
 190     * _swrast_validate_derived():
 191     */
 192    GLbitfield _RasterMask;
 193    GLfloat _BackfaceSign;      /** +1 or -1 */
 194    GLfloat _BackfaceCullSign;  /** +1, 0, or -1 */
 195    GLboolean _PreferPixelFog;    /* Compute fog blend factor per fragment? */
 196    GLboolean _TextureCombinePrimary;
 197    GLboolean _FogEnabled;
 198    GLboolean _DeferredTexture;
 199
 200    /** List/array of the fragment attributes to interpolate */
 201    GLuint _ActiveAttribs[FRAG_ATTRIB_MAX];
 202    /** Same info, but as a bitmask */
 203    GLbitfield _ActiveAttribMask;
 204    /** Number of fragment attributes to interpolate */
 205    GLuint _NumActiveAttribs;
 206    /** Indicates how each attrib is to be interpolated (lines/tris) */
 207    GLenum _InterpMode[FRAG_ATTRIB_MAX]; /* GL_FLAT or GL_SMOOTH (for now) */
 208
 209    /* Accum buffer temporaries.
 210     */
 211    GLboolean _IntegerAccumMode; /**< Storing unscaled integers? */
 212    GLfloat _IntegerAccumScaler; /**< Implicit scale factor */
 213
 214    /* Working values:
 215     */
 216    GLuint StippleCounter;    /**< Line stipple counter */
 217    GLuint PointLineFacing;
 218    GLbitfield NewState;
 219    GLuint StateChanges;
 220    GLenum Primitive;    /* current primitive being drawn (ala glBegin) */
 221    GLboolean SpecularVertexAdd; /**< Add specular/secondary color per vertex */
 222
 223    void (*InvalidateState)( struct gl_context *ctx, GLbitfield new_state );
 224
 225    /**
 226     * When the NewState mask intersects these masks, we invalidate the
 227     * Point/Line/Triangle function pointers below.
 228     */
 229    /*@{*/
 230    GLbitfield InvalidatePointMask;
 231    GLbitfield InvalidateLineMask;
 232    GLbitfield InvalidateTriangleMask;
 233    /*@}*/
 234
 235    /**
 236     * Device drivers plug in functions for these callbacks.
 237     * Will be called when the GL state change mask intersects the above masks.
 238     */
 239    /*@{*/
 240    void (*choose_point)( struct gl_context * );
 241    void (*choose_line)( struct gl_context * );
 242    void (*choose_triangle)( struct gl_context * );
 243    /*@}*/
 244
 245    /**
 246     * Current point, line and triangle drawing functions.
 247     */
 248    /*@{*/
 249    swrast_point_func Point;
 250    swrast_line_func Line;
 251    swrast_tri_func Triangle;
 252    /*@}*/
 253
 254    /**
 255     * Placeholders for when separate specular (or secondary color) is
 256     * enabled but texturing is not.
 257     */
 258    /*@{*/
 259    swrast_point_func SpecPoint;
 260    swrast_line_func SpecLine;
 261    swrast_tri_func SpecTriangle;
 262    /*@}*/
 263
 264    /**
 265     * Typically, we'll allocate a sw_span structure as a local variable
 266     * and set its 'array' pointer to point to this object.  The reason is
 267     * this object is big and causes problems when allocated on the stack
 268     * on some systems.
 269     */
 270    SWspanarrays *SpanArrays;
 271    SWspanarrays *ZoomedArrays;  /**< For pixel zooming */
 272
 273    /**
 274     * Used to buffer N GL_POINTS, instead of rendering one by one.
 275     */
 276    SWspan PointSpan;
 277
 278    /** Internal hooks, kept up to date by the same mechanism as above.
 279     */
 280    blend_func BlendFunc;
 281    texture_sample_func TextureSample[MAX_TEXTURE_IMAGE_UNITS];
 282
 283    /** Buffer for saving the sampled texture colors.
 284     * Needed for GL_ARB_texture_env_crossbar implementation.
 285     */
 286    GLfloat *TexelBuffer;
 287
 288    validate_texture_image_func ValidateTextureImage;
 289
 290    /** State used during execution of fragment programs */
 291    struct gl_program_machine FragProgMachine;
 292
 293 } SWcontext;
 294
 295
 296 extern void
 297 _swrast_validate_derived( struct gl_context *ctx );
 298
 299 extern void
 300 _swrast_update_texture_samplers(struct gl_context *ctx);
 301
 302
 303 /** Return SWcontext for the given struct gl_context */
 304 static inline SWcontext *
 305 SWRAST_CONTEXT(struct gl_context *ctx)
 306 {
 307    return (SWcontext *) ctx->swrast_context;
 308 }
 309
 310 /** const version of above */
 311 static inline const SWcontext *
 312 CONST_SWRAST_CONTEXT(const struct gl_context *ctx)
 313 {
 314    return (const SWcontext *) ctx->swrast_context;
 315 }
 316
 317
 318 /**
 319  * Called prior to framebuffer reading/writing.
 320  * For drivers that rely on swrast for fallback rendering, this is the
 321  * driver's opportunity to map renderbuffers and textures.
 322  */
 323 static inline void
 324 swrast_render_start(struct gl_context *ctx)
 325 {
 326    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 327    if (swrast->Driver.SpanRenderStart)
 328       swrast->Driver.SpanRenderStart(ctx);
 329 }
 330
 331
 332 /** Called after framebuffer reading/writing */
 333 static inline void
 334 swrast_render_finish(struct gl_context *ctx)
 335 {
 336    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 337    if (swrast->Driver.SpanRenderFinish)
 338       swrast->Driver.SpanRenderFinish(ctx);
 339 }
 340
 341
 342
 343 /**
 344  * Size of an RGBA pixel, in bytes, for given datatype.
 345  */
 346 #define RGBA_PIXEL_SIZE(TYPE)                                     \
 347          ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) :      \
 348           ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort)     \
 349            : 4 * sizeof(GLfloat)))
 350
 351
 352
 353 /*
 354  * Fixed point arithmetic macros
 355  */
 356 #ifndef FIXED_FRAC_BITS
 357 #define FIXED_FRAC_BITS 11
 358 #endif
 359
 360 #define FIXED_SHIFT     FIXED_FRAC_BITS
 361 #define FIXED_ONE       (1 << FIXED_SHIFT)
 362 #define FIXED_HALF      (1 << (FIXED_SHIFT-1))
 363 #define FIXED_FRAC_MASK (FIXED_ONE - 1)
 364 #define FIXED_INT_MASK  (~FIXED_FRAC_MASK)
 365 #define FIXED_EPSILON   1
 366 #define FIXED_SCALE     ((float) FIXED_ONE)
 367 #define FIXED_DBL_SCALE ((double) FIXED_ONE)
 368 #define FloatToFixed(X) (IROUND((X) * FIXED_SCALE))
 369 #define FixedToDouble(X) ((X) * (1.0 / FIXED_DBL_SCALE))
 370 #define IntToFixed(I)   ((I) << FIXED_SHIFT)
 371 #define FixedToInt(X)   ((X) >> FIXED_SHIFT)
 372 #define FixedToUns(X)   (((unsigned int)(X)) >> FIXED_SHIFT)
 373 #define FixedCeil(X)    (((X) + FIXED_ONE - FIXED_EPSILON) & FIXED_INT_MASK)
 374 #define FixedFloor(X)   ((X) & FIXED_INT_MASK)
 375 #define FixedToFloat(X) ((X) * (1.0F / FIXED_SCALE))
 376 #define PosFloatToFixed(X)      FloatToFixed(X)
 377 #define SignedFloatToFixed(X)   FloatToFixed(X)
 378
 379
 380
 381 /*
 382  * XXX these macros are just bandages for now in order to make
 383  * CHAN_BITS==32 compile cleanly.
 384  * These should probably go elsewhere at some point.
 385  */
 386 #if CHAN_TYPE == GL_FLOAT
 387 #define ChanToFixed(X)  (X)
 388 #define FixedToChan(X)  (X)
 389 #else
 390 #define ChanToFixed(X)  IntToFixed(X)
 391 #define FixedToChan(X)  FixedToInt(X)
 392 #endif
 393
 394
 395 /**
 396  * For looping over fragment attributes in the pointe, line
 397  * triangle rasterizers.
 398  */
 399 #define ATTRIB_LOOP_BEGIN                                \
 400    {                                                     \
 401       GLuint a;                                          \
 402       for (a = 0; a < swrast->_NumActiveAttribs; a++) {  \
 403          const GLuint attr = swrast->_ActiveAttribs[a];
 404
 405 #define ATTRIB_LOOP_END } }
 406
 407
 408
 409 #endif