src/mesa/swrast/s_context.h

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.2
   4  *
   5  * Copyright (C) 1999-2006  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 "mtypes.h"
  47 #include "swrast.h"
  48
  49
  50 /**
  51  * \defgroup SpanFlags SPAN_XXX-flags
  52  * Bitmasks to indicate which sw_span_arrays need to be computed
  53  * (sw_span::interpMask) or have already been filled in (sw_span::arrayMask)
  54  */
  55 /*@{*/
  56 #define SPAN_RGBA         0x001
  57 #define SPAN_SPEC         0x002
  58 #define SPAN_INDEX        0x004
  59 #define SPAN_Z            0x008
  60 #define SPAN_W            0x010
  61 #define SPAN_FOG          0x020
  62 #define SPAN_TEXTURE      0x040
  63 #define SPAN_INT_TEXTURE  0x080
  64 #define SPAN_LAMBDA       0x100
  65 #define SPAN_COVERAGE     0x200
  66 #define SPAN_FLAT         0x400  /**< flat shading? */
  67 #define SPAN_XY           0x800
  68 #define SPAN_MASK        0x1000
  69 #define SPAN_VARYING     0x2000
  70 /*@}*/
  71
  72 #if 0
  73 /* alternate arrangement for code below */
  74 struct arrays2 {
  75    union {
  76       GLubyte  sz1[MAX_WIDTH][4]; /* primary color */
  77       GLushort sz2[MAX_WIDTH][4];
  78       GLfloat  sz4[MAX_WIDTH][4];
  79    } rgba;
  80    union {
  81       GLubyte  sz1[MAX_WIDTH][4]; /* specular color and temp storage */
  82       GLushort sz2[MAX_WIDTH][4];
  83       GLfloat  sz4[MAX_WIDTH][4];
  84    } spec;
  85 };
  86 #endif
  87
  88
  89
  90 /**
  91  * \sw_span_arrays
  92  * \brief Arrays of fragment values.
  93  *
  94  * These will either be computed from the span x/xStep values or
  95  * filled in by glDraw/CopyPixels, etc.
  96  * These arrays are separated out of sw_span to conserve memory.
  97  */
  98 typedef struct sw_span_arrays {
  99    GLenum ChanType; /**< Color channel type, GL_UNSIGNED_BYTE, GL_FLOAT */
 100    union {
 101       struct {
 102          GLubyte rgba[MAX_WIDTH][4]; /**< primary color */
 103          GLubyte spec[MAX_WIDTH][4]; /**< specular color and temp storage */
 104       } sz1;
 105       struct {
 106          GLushort rgba[MAX_WIDTH][4];
 107          GLushort spec[MAX_WIDTH][4];
 108       } sz2;
 109       struct {
 110          GLfloat rgba[MAX_WIDTH][4];
 111          GLfloat spec[MAX_WIDTH][4];
 112       } sz4;
 113    } color;
 114    /** XXX these are temporary fields, pointing into above color arrays */
 115    GLchan (*rgba)[4];
 116    GLchan (*spec)[4];
 117
 118 #if 0
 119    /* XXX rearrange and unify these arrays to so that we can
 120     * index all fragment inputs with the FRAG_ATTRIB_* values:
 121     */
 122    GLfloat attribs[FRAG_ATTRIB_MAX][MAX_WIDTH][4];
 123    /*OR*/
 124    typedef GLfloat (*array4f)[4];
 125    array4f attribs[FRAG_ATTRIB_MAX];
 126 #endif
 127
 128    GLint   x[MAX_WIDTH];  /**< fragment X coords */
 129    GLint   y[MAX_WIDTH];  /**< fragment Y coords */
 130    GLuint  z[MAX_WIDTH];  /**< fragment Z coords */
 131    GLuint  index[MAX_WIDTH];  /**< Color indexes */
 132    GLfloat fog[MAX_WIDTH];
 133    GLfloat texcoords[MAX_TEXTURE_COORD_UNITS][MAX_WIDTH][4];
 134    GLfloat lambda[MAX_TEXTURE_COORD_UNITS][MAX_WIDTH];
 135    GLfloat coverage[MAX_WIDTH];  /**< Fragment coverage for AA/smoothing */
 136    GLfloat varying[MAX_VARYING][MAX_WIDTH][4]; /**< For shaders */
 137
 138    /** This mask indicates which fragments are alive or culled */
 139    GLubyte mask[MAX_WIDTH];
 140 } SWspanarrays;
 141
 142
 143 /**
 144  * The SWspan structure describes the colors, Z, fogcoord, texcoords,
 145  * etc for either a horizontal run or an array of independent pixels.
 146  * We can either specify a base/step to indicate interpolated values, or
 147  * fill in explicit arrays of values.  The interpMask and arrayMask bitfields
 148  * indicate which attributes are active interpolants or arrays, respectively.
 149  *
 150  * It would be interesting to experiment with multiprocessor rasterization
 151  * with this structure.  The triangle rasterizer could simply emit a
 152  * stream of these structures which would be consumed by one or more
 153  * span-processing threads which could run in parallel.
 154  */
 155 typedef struct sw_span {
 156    GLint x, y;
 157
 158    /** Only need to process pixels between start <= i < end */
 159    /** At this time, start is always zero. */
 160    GLuint start, end;
 161
 162    /** This flag indicates that mask[] array is effectively filled with ones */
 163    GLboolean writeAll;
 164
 165    /** either GL_POLYGON, GL_LINE, GL_POLYGON, GL_BITMAP */
 166    GLenum primitive;
 167
 168    /** 0 = front-facing span, 1 = back-facing span (for two-sided stencil) */
 169    GLuint facing;
 170
 171    /**
 172     * This bitmask (of  \link SpanFlags SPAN_* flags\endlink) indicates
 173     * which of the x/xStep variables are relevant.
 174     */
 175    GLbitfield interpMask;
 176
 177    /* For horizontal spans, step is the partial derivative wrt X.
 178     * For lines, step is the delta from one fragment to the next.
 179     */
 180 #if CHAN_TYPE == GL_FLOAT
 181    GLfloat red, redStep;
 182    GLfloat green, greenStep;
 183    GLfloat blue, blueStep;
 184    GLfloat alpha, alphaStep;
 185    GLfloat specRed, specRedStep;
 186    GLfloat specGreen, specGreenStep;
 187    GLfloat specBlue, specBlueStep;
 188 #else /* CHAN_TYPE == GL_UNSIGNED_BYTE or GL_UNSIGNED_SHORT */
 189    GLfixed red, redStep;
 190    GLfixed green, greenStep;
 191    GLfixed blue, blueStep;
 192    GLfixed alpha, alphaStep;
 193    GLfixed specRed, specRedStep;
 194    GLfixed specGreen, specGreenStep;
 195    GLfixed specBlue, specBlueStep;
 196 #endif
 197    GLfixed index, indexStep;
 198    GLfixed z, zStep;    /* XXX z should probably be GLuint */
 199    GLfloat fog, fogStep;
 200    GLfloat tex[MAX_TEXTURE_COORD_UNITS][4];  /* s, t, r, q */
 201    GLfloat texStepX[MAX_TEXTURE_COORD_UNITS][4];
 202    GLfloat texStepY[MAX_TEXTURE_COORD_UNITS][4];
 203    GLfixed intTex[2], intTexStep[2];  /* s, t only */
 204    GLfloat var[MAX_VARYING][4];
 205    GLfloat varStepX[MAX_VARYING][4];
 206    GLfloat varStepY[MAX_VARYING][4];
 207
 208    /* partial derivatives wrt X and Y. */
 209    GLfloat dzdx, dzdy;
 210    GLfloat w, dwdx, dwdy;
 211    GLfloat drdx, drdy;
 212    GLfloat dgdx, dgdy;
 213    GLfloat dbdx, dbdy;
 214    GLfloat dadx, dady;
 215    GLfloat dsrdx, dsrdy;
 216    GLfloat dsgdx, dsgdy;
 217    GLfloat dsbdx, dsbdy;
 218    GLfloat dfogdx, dfogdy;
 219
 220    /**
 221     * This bitmask (of \link SpanFlags SPAN_* flags\endlink) indicates
 222     * which of the fragment arrays in the span_arrays struct are relevant.
 223     */
 224    GLbitfield arrayMask;
 225
 226    /**
 227     * We store the arrays of fragment values in a separate struct so
 228     * that we can allocate sw_span structs on the stack without using
 229     * a lot of memory.  The span_arrays struct is about 1.4MB while the
 230     * sw_span struct is only about 512 bytes.
 231     */
 232    SWspanarrays *array;
 233 } SWspan;
 234
 235
 236
 237 #define INIT_SPAN(S, PRIMITIVE, END, INTERP_MASK, ARRAY_MASK)   \
 238 do {                                                            \
 239    (S).primitive = (PRIMITIVE);                                 \
 240    (S).interpMask = (INTERP_MASK);                              \
 241    (S).arrayMask = (ARRAY_MASK);                                \
 242    (S).start = 0;                                               \
 243    (S).end = (END);                                             \
 244    (S).facing = 0;                                              \
 245    (S).array = SWRAST_CONTEXT(ctx)->SpanArrays;                 \
 246 } while (0)
 247
 248
 249 typedef void (*texture_sample_func)(GLcontext *ctx,
 250                                     const struct gl_texture_object *tObj,
 251                                     GLuint n, const GLfloat texcoords[][4],
 252                                     const GLfloat lambda[], GLchan rgba[][4]);
 253
 254 typedef void (_ASMAPIP blend_func)( GLcontext *ctx, GLuint n,
 255                                     const GLubyte mask[],
 256                                     GLvoid *src, const GLvoid *dst,
 257                                     GLenum chanType);
 258
 259 typedef void (*swrast_point_func)( GLcontext *ctx, const SWvertex *);
 260
 261 typedef void (*swrast_line_func)( GLcontext *ctx,
 262                                   const SWvertex *, const SWvertex *);
 263
 264 typedef void (*swrast_tri_func)( GLcontext *ctx, const SWvertex *,
 265                                  const SWvertex *, const SWvertex *);
 266
 267
 268 typedef void (*validate_texture_image_func)(GLcontext *ctx,
 269                                             struct gl_texture_object *texObj,
 270                                             GLuint face, GLuint level);
 271
 272
 273 /** \defgroup Bitmasks
 274  * Bitmasks to indicate which rasterization options are enabled
 275  * (RasterMask)
 276  */
 277 /*@{*/
 278 #define ALPHATEST_BIT           0x001   /**< Alpha-test pixels */
 279 #define BLEND_BIT               0x002   /**< Blend pixels */
 280 #define DEPTH_BIT               0x004   /**< Depth-test pixels */
 281 #define FOG_BIT                 0x008   /**< Fog pixels */
 282 #define LOGIC_OP_BIT            0x010   /**< Apply logic op in software */
 283 #define CLIP_BIT                0x020   /**< Scissor or window clip pixels */
 284 #define STENCIL_BIT             0x040   /**< Stencil pixels */
 285 #define MASKING_BIT             0x080   /**< Do glColorMask or glIndexMask */
 286 #define MULTI_DRAW_BIT          0x400   /**< Write to more than one color- */
 287                                         /**< buffer or no buffers. */
 288 #define OCCLUSION_BIT           0x800   /**< GL_HP_occlusion_test enabled */
 289 #define TEXTURE_BIT             0x1000  /**< Texturing really enabled */
 290 #define FRAGPROG_BIT            0x2000  /**< Fragment program enabled */
 291 #define ATIFRAGSHADER_BIT       0x4000  /**< ATI Fragment shader enabled */
 292 #define CLAMPING_BIT            0x8000  /**< Clamp colors to [0,1] */
 293 /*@}*/
 294
 295 #define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS|   \
 296                                 _NEW_SCISSOR|   \
 297                                 _NEW_COLOR|     \
 298                                 _NEW_DEPTH|     \
 299                                 _NEW_FOG|       \
 300                                 _NEW_PROGRAM|   \
 301                                 _NEW_STENCIL|   \
 302                                 _NEW_TEXTURE|   \
 303                                 _NEW_VIEWPORT|  \
 304                                 _NEW_DEPTH)
 305
 306
 307 /**
 308  * \struct SWcontext
 309  * \brief  Per-context state that's private to the software rasterizer module.
 310  */
 311 typedef struct
 312 {
 313    /** Driver interface:
 314     */
 315    struct swrast_device_driver Driver;
 316
 317    /** Configuration mechanisms to make software rasterizer match
 318     * characteristics of the hardware rasterizer (if present):
 319     */
 320    GLboolean AllowVertexFog;
 321    GLboolean AllowPixelFog;
 322
 323    /** Derived values, invalidated on statechanges, updated from
 324     * _swrast_validate_derived():
 325     */
 326    GLbitfield _RasterMask;
 327    GLfloat _BackfaceSign;
 328    GLboolean _PreferPixelFog;    /* Compute fog blend factor per fragment? */
 329    GLboolean _AnyTextureCombine;
 330    GLboolean _FogEnabled;
 331    GLenum _FogMode;  /* either GL_FOG_MODE or fragment program's fog mode */
 332
 333    /* Accum buffer temporaries.
 334     */
 335    GLboolean _IntegerAccumMode; /**< Storing unscaled integers? */
 336    GLfloat _IntegerAccumScaler; /**< Implicit scale factor */
 337
 338    /* Working values:
 339     */
 340    GLuint StippleCounter;    /**< Line stipple counter */
 341    GLbitfield NewState;
 342    GLuint StateChanges;
 343    GLenum Primitive;    /* current primitive being drawn (ala glBegin) */
 344
 345    void (*InvalidateState)( GLcontext *ctx, GLbitfield new_state );
 346
 347    /**
 348     * When the NewState mask intersects these masks, we invalidate the
 349     * Point/Line/Triangle function pointers below.
 350     */
 351    /*@{*/
 352    GLbitfield InvalidatePointMask;
 353    GLbitfield InvalidateLineMask;
 354    GLbitfield InvalidateTriangleMask;
 355    /*@}*/
 356
 357    /**
 358     * Device drivers plug in functions for these callbacks.
 359     * Will be called when the GL state change mask intersects the above masks.
 360     */
 361    /*@{*/
 362    void (*choose_point)( GLcontext * );
 363    void (*choose_line)( GLcontext * );
 364    void (*choose_triangle)( GLcontext * );
 365    /*@}*/
 366
 367    /**
 368     * Current point, line and triangle drawing functions.
 369     */
 370    /*@{*/
 371    swrast_point_func Point;
 372    swrast_line_func Line;
 373    swrast_tri_func Triangle;
 374    /*@}*/
 375
 376    /**
 377     * Placeholders for when separate specular (or secondary color) is
 378     * enabled but texturing is not.
 379     */
 380    /*@{*/
 381    swrast_point_func SpecPoint;
 382    swrast_line_func SpecLine;
 383    swrast_tri_func SpecTriangle;
 384    /*@}*/
 385
 386    /**
 387     * Typically, we'll allocate a sw_span structure as a local variable
 388     * and set its 'array' pointer to point to this object.  The reason is
 389     * this object is big and causes problems when allocated on the stack
 390     * on some systems.
 391     */
 392    SWspanarrays *SpanArrays;
 393
 394    /**
 395     * Used to buffer N GL_POINTS, instead of rendering one by one.
 396     */
 397    SWspan PointSpan;
 398
 399    /** Internal hooks, kept up to date by the same mechanism as above.
 400     */
 401    blend_func BlendFunc;
 402    texture_sample_func TextureSample[MAX_TEXTURE_IMAGE_UNITS];
 403
 404    /** Buffer for saving the sampled texture colors.
 405     * Needed for GL_ARB_texture_env_crossbar implementation.
 406     */
 407    GLchan *TexelBuffer;
 408
 409    validate_texture_image_func ValidateTextureImage;
 410
 411 } SWcontext;
 412
 413
 414 extern void
 415 _swrast_validate_derived( GLcontext *ctx );
 416
 417
 418 #define SWRAST_CONTEXT(ctx) ((SWcontext *)ctx->swrast_context)
 419
 420 #define RENDER_START(SWctx, GLctx)                      \
 421    do {                                                 \
 422       if ((SWctx)->Driver.SpanRenderStart) {            \
 423          (*(SWctx)->Driver.SpanRenderStart)(GLctx);     \
 424       }                                                 \
 425    } while (0)
 426
 427 #define RENDER_FINISH(SWctx, GLctx)                     \
 428    do {                                                 \
 429       if ((SWctx)->Driver.SpanRenderFinish) {           \
 430          (*(SWctx)->Driver.SpanRenderFinish)(GLctx);    \
 431       }                                                 \
 432    } while (0)
 433
 434
 435
 436 /**
 437  * Size of an RGBA pixel, in bytes, for given datatype.
 438  */
 439 #define RGBA_PIXEL_SIZE(TYPE)                                     \
 440          ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) :      \
 441           ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort)     \
 442            : 4 * sizeof(GLfloat)))
 443
 444
 445
 446 /*
 447  * XXX these macros are just bandages for now in order to make
 448  * CHAN_BITS==32 compile cleanly.
 449  * These should probably go elsewhere at some point.
 450  */
 451 #if CHAN_TYPE == GL_FLOAT
 452 #define ChanToFixed(X)  (X)
 453 #define FixedToChan(X)  (X)
 454 #else
 455 #define ChanToFixed(X)  IntToFixed(X)
 456 #define FixedToChan(X)  FixedToInt(X)
 457 #endif
 458
 459 #endif