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      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 (at) 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 
     54 typedef 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 
     60 typedef void (_ASMAPIP blend_func)( struct gl_context *ctx, GLuint n,
     61                                     const GLubyte mask[],
     62                                     GLvoid *src, const GLvoid *dst,
     63                                     GLenum chanType);
     64 
     65 typedef void (*swrast_point_func)( struct gl_context *ctx, const SWvertex *);
     66 
     67 typedef void (*swrast_line_func)( struct gl_context *ctx,
     68                                   const SWvertex *, const SWvertex *);
     69 
     70 typedef void (*swrast_tri_func)( struct gl_context *ctx, const SWvertex *,
     71                                  const SWvertex *, const SWvertex *);
     72 
     73 
     74 typedef 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 
    114 struct swrast_texture_image;
    115 
    116 
    117 /**
    118  * Fetch a texel from texture image at given position.
    119  */
    120 typedef 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  */
    130 struct 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 */
    153 static inline struct swrast_texture_image *
    154 swrast_texture_image(struct gl_texture_image *img)
    155 {
    156    return (struct swrast_texture_image *) img;
    157 }
    158 
    159 /** cast wrapper */
    160 static inline const struct swrast_texture_image *
    161 swrast_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  */
    171 struct 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 */
    187 static inline struct swrast_renderbuffer *
    188 swrast_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  */
    199 typedef 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 
    320 extern void
    321 _swrast_validate_derived( struct gl_context *ctx );
    322 
    323 extern void
    324 _swrast_update_texture_samplers(struct gl_context *ctx);
    325 
    326 
    327 /** Return SWcontext for the given struct gl_context */
    328 static inline SWcontext *
    329 SWRAST_CONTEXT(struct gl_context *ctx)
    330 {
    331    return (SWcontext *) ctx->swrast_context;
    332 }
    333 
    334 /** const version of above */
    335 static inline const SWcontext *
    336 CONST_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  */
    347 static inline void
    348 swrast_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 */
    357 static inline void
    358 swrast_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 
    366 extern void
    367 _swrast_span_render_start(struct gl_context *ctx);
    368 
    369 extern void
    370 _swrast_span_render_finish(struct gl_context *ctx);
    371 
    372 extern void
    373 _swrast_map_textures(struct gl_context *ctx);
    374 
    375 extern void
    376 _swrast_unmap_textures(struct gl_context *ctx);
    377 
    378 extern void
    379 _swrast_map_texture(struct gl_context *ctx, struct gl_texture_object *texObj);
    380 
    381 extern void
    382 _swrast_unmap_texture(struct gl_context *ctx, struct gl_texture_object *texObj);
    383 
    384 
    385 extern void
    386 _swrast_map_renderbuffers(struct gl_context *ctx);
    387 
    388 extern 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  */
    460 static 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