src/mesa/swrast/s_context.h

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.1
   4  *
   5  * Copyright (C) 1999-2004  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 #ifndef S_CONTEXT_H
  33 #define S_CONTEXT_H
  34
  35 #include "mtypes.h"
  36 #include "swrast.h"
  37
  38
  39 /**
  40  * \defgroup SpanFlags SPAN_XXX-flags
  41  * Bitmasks to indicate which span_arrays need to be computed
  42  * (sw_span::interpMask) or have already been filled
  43  * (sw_span::arrayMask)
  44  */
  45 /*@{*/
  46 #define SPAN_RGBA         0x001
  47 #define SPAN_SPEC         0x002
  48 #define SPAN_INDEX        0x004
  49 #define SPAN_Z            0x008
  50 #define SPAN_W            0x010
  51 #define SPAN_FOG          0x020
  52 #define SPAN_TEXTURE      0x040
  53 #define SPAN_INT_TEXTURE  0x080
  54 #define SPAN_LAMBDA       0x100
  55 #define SPAN_COVERAGE     0x200
  56 #define SPAN_FLAT         0x400  /**< flat shading? */
  57 /** sw_span::arrayMask only - for span_arrays::x, span_arrays::y */
  58 #define SPAN_XY           0x800
  59 #define SPAN_MASK        0x1000  /**< sw_span::arrayMask only */
  60 /*@}*/
  61
  62
  63 /**
  64  * \struct span_arrays
  65  * \brief Arrays of fragment values.
  66  *
  67  * These will either be computed from the x/xStep values above or
  68  * filled in by glDraw/CopyPixels, etc.
  69  * These arrays are separated out of sw_span to conserve memory.
  70  */
  71 struct span_arrays {
  72    GLchan  rgb[MAX_WIDTH][3];
  73    GLchan  rgba[MAX_WIDTH][4];
  74    GLuint  index[MAX_WIDTH];
  75    GLchan  spec[MAX_WIDTH][4]; /* specular color */
  76    GLint   x[MAX_WIDTH];  /**< X/Y used for point/line rendering only */
  77    GLint   y[MAX_WIDTH];  /**< X/Y used for point/line rendering only */
  78    GLdepth z[MAX_WIDTH];
  79    GLfloat fog[MAX_WIDTH];
  80    GLfloat texcoords[MAX_TEXTURE_COORD_UNITS][MAX_WIDTH][4];
  81    GLfloat lambda[MAX_TEXTURE_COORD_UNITS][MAX_WIDTH];
  82    GLfloat coverage[MAX_WIDTH];
  83
  84    /** This mask indicates if fragment is alive or culled */
  85    GLubyte mask[MAX_WIDTH];
  86 };
  87
  88
  89 /**
  90  * \struct sw_span
  91  * \brief Contains data for either a horizontal line or a set of
  92  * pixels that are passed through a pipeline of functions before being
  93  * drawn.
  94  *
  95  * The sw_span structure describes the colors, Z, fogcoord, texcoords,
  96  * etc for either a horizontal run or an array of independent pixels.
  97  * We can either specify a base/step to indicate interpolated values, or
  98  * fill in arrays of values.  The interpMask and arrayMask bitfields
  99  * indicate which are active.
 100  *
 101  * With this structure it's easy to hand-off span rasterization to
 102  * subroutines instead of doing it all inline in the triangle functions
 103  * like we used to do.
 104  * It also cleans up the local variable namespace a great deal.
 105  *
 106  * It would be interesting to experiment with multiprocessor rasterization
 107  * with this structure.  The triangle rasterizer could simply emit a
 108  * stream of these structures which would be consumed by one or more
 109  * span-processing threads which could run in parallel.
 110  */
 111 struct sw_span {
 112    GLint x, y;
 113
 114    /** Only need to process pixels between start <= i < end */
 115    /** At this time, start is always zero. */
 116    GLuint start, end;
 117
 118    /** This flag indicates that mask[] array is effectively filled with ones */
 119    GLboolean writeAll;
 120
 121    /** either GL_POLYGON, GL_LINE, GL_POLYGON, GL_BITMAP */
 122    GLenum primitive;
 123
 124    /** 0 = front-facing span, 1 = back-facing span (for two-sided stencil) */
 125    GLuint facing;
 126
 127    /**
 128     * This bitmask (of  \link SpanFlags SPAN_* flags\endlink) indicates
 129     * which of the x/xStep variables are relevant.
 130     */
 131    GLuint interpMask;
 132
 133    /* For horizontal spans, step is the partial derivative wrt X.
 134     * For lines, step is the delta from one fragment to the next.
 135     */
 136 #if CHAN_TYPE == GL_FLOAT
 137    GLfloat red, redStep;
 138    GLfloat green, greenStep;
 139    GLfloat blue, blueStep;
 140    GLfloat alpha, alphaStep;
 141    GLfloat specRed, specRedStep;
 142    GLfloat specGreen, specGreenStep;
 143    GLfloat specBlue, specBlueStep;
 144 #else /* CHAN_TYPE == GL_UNSIGNED_BYTE or GL_UNSIGNED_SHORT */
 145    GLfixed red, redStep;
 146    GLfixed green, greenStep;
 147    GLfixed blue, blueStep;
 148    GLfixed alpha, alphaStep;
 149    GLfixed specRed, specRedStep;
 150    GLfixed specGreen, specGreenStep;
 151    GLfixed specBlue, specBlueStep;
 152 #endif
 153    GLfixed index, indexStep;
 154    GLfixed z, zStep;
 155    GLfloat fog, fogStep;
 156    GLfloat tex[MAX_TEXTURE_COORD_UNITS][4];  /* s, t, r, q */
 157    GLfloat texStepX[MAX_TEXTURE_COORD_UNITS][4];
 158    GLfloat texStepY[MAX_TEXTURE_COORD_UNITS][4];
 159    GLfixed intTex[2], intTexStep[2];  /* s, t only */
 160
 161    /* partial derivatives wrt X and Y. */
 162    GLfloat dzdx, dzdy;
 163    GLfloat w, dwdx, dwdy;
 164    GLfloat drdx, drdy;
 165    GLfloat dgdx, dgdy;
 166    GLfloat dbdx, dbdy;
 167    GLfloat dadx, dady;
 168    GLfloat dsrdx, dsrdy;
 169    GLfloat dsgdx, dsgdy;
 170    GLfloat dsbdx, dsbdy;
 171    GLfloat dfogdx, dfogdy;
 172
 173    /**
 174     * This bitmask (of \link SpanFlags SPAN_* flags\endlink) indicates
 175     * which of the fragment arrays in the span_arrays struct are relevant.
 176     */
 177    GLuint arrayMask;
 178
 179    /**
 180     * We store the arrays of fragment values in a separate struct so
 181     * that we can allocate sw_span structs on the stack without using
 182     * a lot of memory.  The span_arrays struct is about 400KB while the
 183     * sw_span struct is only about 512 bytes.
 184     */
 185    struct span_arrays *array;
 186 };
 187
 188
 189 #define INIT_SPAN(S, PRIMITIVE, END, INTERP_MASK, ARRAY_MASK)   \
 190 do {                                                            \
 191    (S).primitive = (PRIMITIVE);                                 \
 192    (S).interpMask = (INTERP_MASK);                              \
 193    (S).arrayMask = (ARRAY_MASK);                                \
 194    (S).start = 0;                                               \
 195    (S).end = (END);                                             \
 196    (S).facing = 0;                                              \
 197    (S).array = SWRAST_CONTEXT(ctx)->SpanArrays;                 \
 198 } while (0)
 199
 200
 201 typedef void (*texture_sample_func)(GLcontext *ctx, GLuint texUnit,
 202                                     const struct gl_texture_object *tObj,
 203                                     GLuint n, const GLfloat texcoords[][4],
 204                                     const GLfloat lambda[], GLchan rgba[][4]);
 205
 206 typedef void (_ASMAPIP blend_func)( GLcontext *ctx, GLuint n,
 207                                     const GLubyte mask[],
 208                                     GLchan src[][4], CONST GLchan dst[][4] );
 209
 210 typedef void (*swrast_point_func)( GLcontext *ctx, const SWvertex *);
 211
 212 typedef void (*swrast_line_func)( GLcontext *ctx,
 213                                   const SWvertex *, const SWvertex *);
 214
 215 typedef void (*swrast_tri_func)( GLcontext *ctx, const SWvertex *,
 216                                  const SWvertex *, const SWvertex *);
 217
 218
 219 /** \defgroup Bitmasks
 220  * Bitmasks to indicate which rasterization options are enabled
 221  * (RasterMask)
 222  */
 223 /*@{*/
 224 #define ALPHATEST_BIT           0x001   /**< Alpha-test pixels */
 225 #define BLEND_BIT               0x002   /**< Blend pixels */
 226 #define DEPTH_BIT               0x004   /**< Depth-test pixels */
 227 #define FOG_BIT                 0x008   /**< Fog pixels */
 228 #define LOGIC_OP_BIT            0x010   /**< Apply logic op in software */
 229 #define CLIP_BIT                0x020   /**< Scissor or window clip pixels */
 230 #define STENCIL_BIT             0x040   /**< Stencil pixels */
 231 #define MASKING_BIT             0x080   /**< Do glColorMask or glIndexMask */
 232 #define ALPHABUF_BIT            0x100   /**< Using software alpha buffer */
 233 #define MULTI_DRAW_BIT          0x400   /**< Write to more than one color- */
 234                                         /**< buffer or no buffers. */
 235 #define OCCLUSION_BIT           0x800   /**< GL_HP_occlusion_test enabled */
 236 #define TEXTURE_BIT             0x1000  /**< Texturing really enabled */
 237 #define FRAGPROG_BIT            0x2000  /**< Fragment program enabled */
 238 /*@}*/
 239
 240 #define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS|   \
 241                                 _NEW_SCISSOR|   \
 242                                 _NEW_COLOR|     \
 243                                 _NEW_DEPTH|     \
 244                                 _NEW_FOG|       \
 245                                 _NEW_PROGRAM|   \
 246                                 _NEW_STENCIL|   \
 247                                 _NEW_TEXTURE|   \
 248                                 _NEW_VIEWPORT|  \
 249                                 _NEW_DEPTH)
 250
 251
 252 /**
 253  * \struct SWcontext
 254  * \brief SWContext?
 255  */
 256 typedef struct
 257 {
 258    /** Driver interface:
 259     */
 260    struct swrast_device_driver Driver;
 261
 262    /** Configuration mechanisms to make software rasterizer match
 263     * characteristics of the hardware rasterizer (if present):
 264     */
 265    GLboolean AllowVertexFog;
 266    GLboolean AllowPixelFog;
 267
 268    /** Derived values, invalidated on statechanges, updated from
 269     * _swrast_validate_derived():
 270     */
 271    GLuint _RasterMask;
 272    GLfloat _MinMagThresh[MAX_TEXTURE_IMAGE_UNITS];
 273    GLfloat _BackfaceSign;
 274    GLboolean _PreferPixelFog;    /* Compute fog blend factor per fragment? */
 275    GLboolean _AnyTextureCombine;
 276    GLchan _FogColor[3];
 277    GLboolean _FogEnabled;
 278
 279    /* Accum buffer temporaries.
 280     */
 281    GLboolean _IntegerAccumMode; /**< Storing unscaled integers? */
 282    GLfloat _IntegerAccumScaler; /**< Implicit scale factor */
 283
 284    GLchan *CurAuxBuffer;
 285
 286    /* Working values:
 287     */
 288    GLuint StippleCounter;    /**< Line stipple counter */
 289    GLuint NewState;
 290    GLuint StateChanges;
 291    GLenum Primitive;    /* current primitive being drawn (ala glBegin) */
 292    GLbitfield CurrentBufferBit; /* exactly one the of DD_*_BIT buffer bits */
 293
 294    /** Mechanism to allow driver (like X11) to register further
 295     * software rasterization routines.
 296     */
 297    /*@{*/
 298    void (*choose_point)( GLcontext * );
 299    void (*choose_line)( GLcontext * );
 300    void (*choose_triangle)( GLcontext * );
 301
 302    GLuint invalidate_point;
 303    GLuint invalidate_line;
 304    GLuint invalidate_triangle;
 305    /*@}*/
 306
 307    /** Function pointers for dispatch behind public entrypoints. */
 308    /*@{*/
 309    void (*InvalidateState)( GLcontext *ctx, GLuint new_state );
 310
 311    swrast_point_func Point;
 312    swrast_line_func Line;
 313    swrast_tri_func Triangle;
 314    /*@}*/
 315
 316    /**
 317     * Placeholders for when separate specular (or secondary color) is
 318     * enabled but texturing is not.
 319     */
 320    /*@{*/
 321    swrast_point_func SpecPoint;
 322    swrast_line_func SpecLine;
 323    swrast_tri_func SpecTriangle;
 324    /*@}*/
 325
 326    /**
 327     * Typically, we'll allocate a sw_span structure as a local variable
 328     * and set its 'array' pointer to point to this object.  The reason is
 329     * this object is big and causes problems when allocated on the stack
 330     * on some systems.
 331     */
 332    struct span_arrays *SpanArrays;
 333
 334    /**
 335     * Used to buffer N GL_POINTS, instead of rendering one by one.
 336     */
 337    struct sw_span PointSpan;
 338
 339    /** Internal hooks, kept uptodate by the same mechanism as above.
 340     */
 341    blend_func BlendFunc;
 342    texture_sample_func TextureSample[MAX_TEXTURE_IMAGE_UNITS];
 343
 344    /** Buffer for saving the sampled texture colors.
 345     * Needed for GL_ARB_texture_env_crossbar implementation.
 346     */
 347    GLchan *TexelBuffer;
 348
 349 } SWcontext;
 350
 351
 352 extern void
 353 _swrast_validate_derived( GLcontext *ctx );
 354
 355
 356 #define SWRAST_CONTEXT(ctx) ((SWcontext *)ctx->swrast_context)
 357
 358 #define RENDER_START(SWctx, GLctx)                      \
 359    do {                                                 \
 360       if ((SWctx)->Driver.SpanRenderStart) {            \
 361          (*(SWctx)->Driver.SpanRenderStart)(GLctx);     \
 362       }                                                 \
 363    } while (0)
 364
 365 #define RENDER_FINISH(SWctx, GLctx)                     \
 366    do {                                                 \
 367       if ((SWctx)->Driver.SpanRenderFinish) {           \
 368          (*(SWctx)->Driver.SpanRenderFinish)(GLctx);    \
 369       }                                                 \
 370    } while (0)
 371
 372
 373
 374 /*
 375  * XXX these macros are just bandages for now in order to make
 376  * CHAN_BITS==32 compile cleanly.
 377  * These should probably go elsewhere at some point.
 378  */
 379 #if CHAN_TYPE == GL_FLOAT
 380 #define ChanToFixed(X)  (X)
 381 #define FixedToChan(X)  (X)
 382 #else
 383 #define ChanToFixed(X)  IntToFixed(X)
 384 #define FixedToChan(X)  FixedToInt(X)
 385 #endif
 386
 387
 388
 389 extern void
 390 _swrast_translate_program( GLcontext *ctx );
 391
 392 extern GLboolean
 393 _swrast_execute_codegen_program(GLcontext *ctx,
 394                                 const struct fragment_program *program,
 395                                 GLuint maxInst,
 396                                 struct fp_machine *machine,
 397                                 const struct sw_span *span,
 398                                 GLuint column );
 399
 400
 401 #endif