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 /**
 113  * \struct SWcontext
 114  * \brief  Per-context state that's private to the software rasterizer module.
 115  */
 116 typedef struct
 117 {
 118    /** Driver interface:
 119     */
 120    struct swrast_device_driver Driver;
 121
 122    /** Configuration mechanisms to make software rasterizer match
 123     * characteristics of the hardware rasterizer (if present):
 124     */
 125    GLboolean AllowVertexFog;
 126    GLboolean AllowPixelFog;
 127
 128    /** Derived values, invalidated on statechanges, updated from
 129     * _swrast_validate_derived():
 130     */
 131    GLbitfield _RasterMask;
 132    GLfloat _BackfaceSign;      /** +1 or -1 */
 133    GLfloat _BackfaceCullSign;  /** +1, 0, or -1 */
 134    GLboolean _PreferPixelFog;    /* Compute fog blend factor per fragment? */
 135    GLboolean _TextureCombinePrimary;
 136    GLboolean _FogEnabled;
 137    GLboolean _DeferredTexture;
 138    GLenum _FogMode;  /* either GL_FOG_MODE or fragment program's fog mode */
 139
 140    /** List/array of the fragment attributes to interpolate */
 141    GLuint _ActiveAttribs[FRAG_ATTRIB_MAX];
 142    /** Same info, but as a bitmask */
 143    GLbitfield _ActiveAttribMask;
 144    /** Number of fragment attributes to interpolate */
 145    GLuint _NumActiveAttribs;
 146    /** Indicates how each attrib is to be interpolated (lines/tris) */
 147    GLenum _InterpMode[FRAG_ATTRIB_MAX]; /* GL_FLAT or GL_SMOOTH (for now) */
 148
 149    /* Accum buffer temporaries.
 150     */
 151    GLboolean _IntegerAccumMode; /**< Storing unscaled integers? */
 152    GLfloat _IntegerAccumScaler; /**< Implicit scale factor */
 153
 154    /* Working values:
 155     */
 156    GLuint StippleCounter;    /**< Line stipple counter */
 157    GLuint PointLineFacing;
 158    GLbitfield NewState;
 159    GLuint StateChanges;
 160    GLenum Primitive;    /* current primitive being drawn (ala glBegin) */
 161    GLboolean SpecularVertexAdd; /**< Add specular/secondary color per vertex */
 162
 163    void (*InvalidateState)( struct gl_context *ctx, GLbitfield new_state );
 164
 165    /**
 166     * When the NewState mask intersects these masks, we invalidate the
 167     * Point/Line/Triangle function pointers below.
 168     */
 169    /*@{*/
 170    GLbitfield InvalidatePointMask;
 171    GLbitfield InvalidateLineMask;
 172    GLbitfield InvalidateTriangleMask;
 173    /*@}*/
 174
 175    /**
 176     * Device drivers plug in functions for these callbacks.
 177     * Will be called when the GL state change mask intersects the above masks.
 178     */
 179    /*@{*/
 180    void (*choose_point)( struct gl_context * );
 181    void (*choose_line)( struct gl_context * );
 182    void (*choose_triangle)( struct gl_context * );
 183    /*@}*/
 184
 185    /**
 186     * Current point, line and triangle drawing functions.
 187     */
 188    /*@{*/
 189    swrast_point_func Point;
 190    swrast_line_func Line;
 191    swrast_tri_func Triangle;
 192    /*@}*/
 193
 194    /**
 195     * Placeholders for when separate specular (or secondary color) is
 196     * enabled but texturing is not.
 197     */
 198    /*@{*/
 199    swrast_point_func SpecPoint;
 200    swrast_line_func SpecLine;
 201    swrast_tri_func SpecTriangle;
 202    /*@}*/
 203
 204    /**
 205     * Typically, we'll allocate a sw_span structure as a local variable
 206     * and set its 'array' pointer to point to this object.  The reason is
 207     * this object is big and causes problems when allocated on the stack
 208     * on some systems.
 209     */
 210    SWspanarrays *SpanArrays;
 211    SWspanarrays *ZoomedArrays;  /**< For pixel zooming */
 212
 213    /**
 214     * Used to buffer N GL_POINTS, instead of rendering one by one.
 215     */
 216    SWspan PointSpan;
 217
 218    /** Internal hooks, kept up to date by the same mechanism as above.
 219     */
 220    blend_func BlendFunc;
 221    texture_sample_func TextureSample[MAX_TEXTURE_IMAGE_UNITS];
 222
 223    /** Buffer for saving the sampled texture colors.
 224     * Needed for GL_ARB_texture_env_crossbar implementation.
 225     */
 226    GLfloat *TexelBuffer;
 227
 228    validate_texture_image_func ValidateTextureImage;
 229
 230    /** State used during execution of fragment programs */
 231    struct gl_program_machine FragProgMachine;
 232
 233 } SWcontext;
 234
 235
 236 extern void
 237 _swrast_validate_derived( struct gl_context *ctx );
 238
 239 extern void
 240 _swrast_update_texture_samplers(struct gl_context *ctx);
 241
 242
 243 /** Return SWcontext for the given struct gl_context */
 244 static INLINE SWcontext *
 245 SWRAST_CONTEXT(struct gl_context *ctx)
 246 {
 247    return (SWcontext *) ctx->swrast_context;
 248 }
 249
 250 /** const version of above */
 251 static INLINE const SWcontext *
 252 CONST_SWRAST_CONTEXT(const struct gl_context *ctx)
 253 {
 254    return (const SWcontext *) ctx->swrast_context;
 255 }
 256
 257
 258 /**
 259  * Called prior to framebuffer reading/writing.
 260  * For drivers that rely on swrast for fallback rendering, this is the
 261  * driver's opportunity to map renderbuffers and textures.
 262  */
 263 static INLINE void
 264 swrast_render_start(struct gl_context *ctx)
 265 {
 266    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 267    if (swrast->Driver.SpanRenderStart)
 268       swrast->Driver.SpanRenderStart(ctx);
 269 }
 270
 271
 272 /** Called after framebuffer reading/writing */
 273 static INLINE void
 274 swrast_render_finish(struct gl_context *ctx)
 275 {
 276    SWcontext *swrast = SWRAST_CONTEXT(ctx);
 277    if (swrast->Driver.SpanRenderFinish)
 278       swrast->Driver.SpanRenderFinish(ctx);
 279 }
 280
 281
 282
 283 /**
 284  * Size of an RGBA pixel, in bytes, for given datatype.
 285  */
 286 #define RGBA_PIXEL_SIZE(TYPE)                                     \
 287          ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) :      \
 288           ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort)     \
 289            : 4 * sizeof(GLfloat)))
 290
 291
 292
 293 /*
 294  * Fixed point arithmetic macros
 295  */
 296 #ifndef FIXED_FRAC_BITS
 297 #define FIXED_FRAC_BITS 11
 298 #endif
 299
 300 #define FIXED_SHIFT     FIXED_FRAC_BITS
 301 #define FIXED_ONE       (1 << FIXED_SHIFT)
 302 #define FIXED_HALF      (1 << (FIXED_SHIFT-1))
 303 #define FIXED_FRAC_MASK (FIXED_ONE - 1)
 304 #define FIXED_INT_MASK  (~FIXED_FRAC_MASK)
 305 #define FIXED_EPSILON   1
 306 #define FIXED_SCALE     ((float) FIXED_ONE)
 307 #define FIXED_DBL_SCALE ((double) FIXED_ONE)
 308 #define FloatToFixed(X) (IROUND((X) * FIXED_SCALE))
 309 #define FixedToDouble(X) ((X) * (1.0 / FIXED_DBL_SCALE))
 310 #define IntToFixed(I)   ((I) << FIXED_SHIFT)
 311 #define FixedToInt(X)   ((X) >> FIXED_SHIFT)
 312 #define FixedToUns(X)   (((unsigned int)(X)) >> FIXED_SHIFT)
 313 #define FixedCeil(X)    (((X) + FIXED_ONE - FIXED_EPSILON) & FIXED_INT_MASK)
 314 #define FixedFloor(X)   ((X) & FIXED_INT_MASK)
 315 #define FixedToFloat(X) ((X) * (1.0F / FIXED_SCALE))
 316 #define PosFloatToFixed(X)      FloatToFixed(X)
 317 #define SignedFloatToFixed(X)   FloatToFixed(X)
 318
 319
 320
 321 /*
 322  * XXX these macros are just bandages for now in order to make
 323  * CHAN_BITS==32 compile cleanly.
 324  * These should probably go elsewhere at some point.
 325  */
 326 #if CHAN_TYPE == GL_FLOAT
 327 #define ChanToFixed(X)  (X)
 328 #define FixedToChan(X)  (X)
 329 #else
 330 #define ChanToFixed(X)  IntToFixed(X)
 331 #define FixedToChan(X)  FixedToInt(X)
 332 #endif
 333
 334
 335 /**
 336  * For looping over fragment attributes in the pointe, line
 337  * triangle rasterizers.
 338  */
 339 #define ATTRIB_LOOP_BEGIN                                \
 340    {                                                     \
 341       GLuint a;                                          \
 342       for (a = 0; a < swrast->_NumActiveAttribs; a++) {  \
 343          const GLuint attr = swrast->_ActiveAttribs[a];
 344
 345 #define ATTRIB_LOOP_END } }
 346
 347
 348
 349 #endif