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      1 /*
      2  * Mesa 3-D graphics library
      3  *
      4  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a
      7  * copy of this software and associated documentation files (the "Software"),
      8  * to deal in the Software without restriction, including without limitation
      9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     10  * and/or sell copies of the Software, and to permit persons to whom the
     11  * Software is furnished to do so, subject to the following conditions:
     12  *
     13  * The above copyright notice and this permission notice shall be included
     14  * in all copies or substantial portions of the Software.
     15  *
     16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
     20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
     21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     22  * 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 <keithw (at) vmware.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 "main/texcompress.h"
     49 #include "program/prog_execute.h"
     50 #include "swrast.h"
     51 #include "s_fragprog.h"
     52 #include "s_span.h"
     53 
     54 
     55 typedef void (*texture_sample_func)(struct gl_context *ctx,
     56                                     const struct gl_sampler_object *samp,
     57                                     const struct gl_texture_object *tObj,
     58                                     GLuint n, const GLfloat texcoords[][4],
     59                                     const GLfloat lambda[], GLfloat rgba[][4]);
     60 
     61 typedef void (*blend_func)(struct gl_context *ctx, GLuint n,
     62                            const GLubyte mask[],
     63                            GLvoid *src, const GLvoid *dst,
     64                            GLenum chanType);
     65 
     66 typedef void (*swrast_point_func)( struct gl_context *ctx, const SWvertex *);
     67 
     68 typedef void (*swrast_line_func)( struct gl_context *ctx,
     69                                   const SWvertex *, const SWvertex *);
     70 
     71 typedef void (*swrast_tri_func)( struct gl_context *ctx, const SWvertex *,
     72                                  const SWvertex *, const SWvertex *);
     73 
     74 
     75 typedef void (*validate_texture_image_func)(struct gl_context *ctx,
     76                                             struct gl_texture_object *texObj,
     77                                             GLuint face, GLuint level);
     78 
     79 
     80 /**
     81  * \defgroup Bitmasks
     82  * Bitmasks to indicate which rasterization options are enabled
     83  * (RasterMask)
     84  */
     85 /*@{*/
     86 #define ALPHATEST_BIT		0x001	/**< Alpha-test pixels */
     87 #define BLEND_BIT		0x002	/**< Blend pixels */
     88 #define DEPTH_BIT		0x004	/**< Depth-test pixels */
     89 #define FOG_BIT			0x008	/**< Fog pixels */
     90 #define LOGIC_OP_BIT		0x010	/**< Apply logic op in software */
     91 #define CLIP_BIT		0x020	/**< Scissor or window clip pixels */
     92 #define STENCIL_BIT		0x040	/**< Stencil pixels */
     93 #define MASKING_BIT		0x080	/**< Do glColorMask or glIndexMask */
     94 #define MULTI_DRAW_BIT		0x400	/**< Write to more than one color- */
     95                                         /**< buffer or no buffers. */
     96 #define OCCLUSION_BIT           0x800   /**< GL_HP_occlusion_test enabled */
     97 #define TEXTURE_BIT		0x1000	/**< Texturing really enabled */
     98 #define FRAGPROG_BIT            0x2000  /**< Fragment program enabled */
     99 #define ATIFRAGSHADER_BIT       0x4000  /**< ATI Fragment shader enabled */
    100 #define CLAMPING_BIT            0x8000  /**< Clamp colors to [0,1] */
    101 /*@}*/
    102 
    103 #define _SWRAST_NEW_RASTERMASK (_NEW_BUFFERS|	\
    104 			        _NEW_SCISSOR|	\
    105 			        _NEW_COLOR|	\
    106 			        _NEW_DEPTH|	\
    107 			        _NEW_FOG|	\
    108                                 _NEW_PROGRAM|   \
    109 			        _NEW_STENCIL|	\
    110 			        _NEW_TEXTURE|	\
    111 			        _NEW_VIEWPORT|	\
    112 			        _NEW_DEPTH)
    113 
    114 
    115 struct swrast_texture_image;
    116 
    117 
    118 /**
    119  * Fetch a texel from texture image at given position.
    120  */
    121 typedef void (*FetchTexelFunc)(const struct swrast_texture_image *texImage,
    122                                GLint col, GLint row, GLint img,
    123                                GLfloat *texelOut);
    124 
    125 
    126 /**
    127  * Subclass of gl_texture_image.
    128  * We need extra fields/info to keep tracking of mapped texture buffers,
    129  * strides and Fetch functions.
    130  */
    131 struct swrast_texture_image
    132 {
    133    struct gl_texture_image Base;
    134 
    135    GLboolean _IsPowerOfTwo;  /**< Are all dimensions powers of two? */
    136 
    137    /** used for mipmap LOD computation */
    138    GLfloat WidthScale, HeightScale, DepthScale;
    139 
    140    /**
    141     * Byte stride between rows in ImageSlices.
    142     *
    143     * For compressed textures, this is the byte stride between one row of
    144     * blocks and the next row of blocks.
    145     *
    146     * Only valid while one of the ImageSlices is mapped, and must be the same
    147     * between all slices.
    148     */
    149    GLint RowStride;
    150    /**
    151     * When a texture image is mapped for swrast, this array contains pointers
    152     * to the beginning of each slice.
    153     *
    154     * For swrast-allocated textures, these pointers will always stay
    155     * initialized to point within Buffer.
    156     */
    157    void **ImageSlices;
    158 
    159    /** Malloc'd texture memory */
    160    GLubyte *Buffer;
    161 
    162    FetchTexelFunc FetchTexel;
    163 
    164    /** For fetching texels from compressed textures */
    165    compressed_fetch_func FetchCompressedTexel;
    166 };
    167 
    168 
    169 /** cast wrapper */
    170 static inline struct swrast_texture_image *
    171 swrast_texture_image(struct gl_texture_image *img)
    172 {
    173    return (struct swrast_texture_image *) img;
    174 }
    175 
    176 /** cast wrapper */
    177 static inline const struct swrast_texture_image *
    178 swrast_texture_image_const(const struct gl_texture_image *img)
    179 {
    180    return (const struct swrast_texture_image *) img;
    181 }
    182 
    183 
    184 /**
    185  * Subclass of gl_renderbuffer with extra fields needed for software
    186  * rendering.
    187  */
    188 struct swrast_renderbuffer
    189 {
    190    struct gl_renderbuffer Base;
    191 
    192    GLubyte *Buffer;     /**< The malloc'd memory for buffer */
    193 
    194    /** These fields are only valid while buffer is mapped for rendering */
    195    GLubyte *Map;
    196    GLint RowStride;    /**< in bytes */
    197 
    198    /** For span rendering */
    199    GLenum ColorType;
    200 };
    201 
    202 
    203 /** cast wrapper */
    204 static inline struct swrast_renderbuffer *
    205 swrast_renderbuffer(struct gl_renderbuffer *img)
    206 {
    207    return (struct swrast_renderbuffer *) img;
    208 }
    209 
    210 
    211 
    212 /**
    213  * \struct SWcontext
    214  * \brief  Per-context state that's private to the software rasterizer module.
    215  */
    216 typedef struct
    217 {
    218    /** Driver interface:
    219     */
    220    struct swrast_device_driver Driver;
    221 
    222    /** Configuration mechanisms to make software rasterizer match
    223     * characteristics of the hardware rasterizer (if present):
    224     */
    225    GLboolean AllowVertexFog;
    226    GLboolean AllowPixelFog;
    227 
    228    /** Derived values, invalidated on statechanges, updated from
    229     * _swrast_validate_derived():
    230     */
    231    GLbitfield _RasterMask;
    232    GLfloat _BackfaceSign;      /** +1 or -1 */
    233    GLfloat _BackfaceCullSign;  /** +1, 0, or -1 */
    234    GLboolean _PreferPixelFog;    /* Compute fog blend factor per fragment? */
    235    GLboolean _TextureCombinePrimary;
    236    GLboolean _FogEnabled;
    237    GLboolean _DeferredTexture;
    238 
    239    /** List/array of the fragment attributes to interpolate */
    240    GLuint _ActiveAttribs[VARYING_SLOT_MAX];
    241    /** Same info, but as a bitmask of VARYING_BIT_x bits */
    242    GLbitfield64 _ActiveAttribMask;
    243    /** Number of fragment attributes to interpolate */
    244    GLuint _NumActiveAttribs;
    245    /** Indicates how each attrib is to be interpolated (lines/tris) */
    246    GLenum _InterpMode[VARYING_SLOT_MAX]; /* GL_FLAT or GL_SMOOTH (for now) */
    247 
    248    /* Working values:
    249     */
    250    GLuint StippleCounter;    /**< Line stipple counter */
    251    GLuint PointLineFacing;
    252    GLbitfield NewState;
    253    GLuint StateChanges;
    254    GLenum Primitive;    /* current primitive being drawn (ala glBegin) */
    255    GLboolean SpecularVertexAdd; /**< Add specular/secondary color per vertex */
    256 
    257    void (*InvalidateState)( struct gl_context *ctx, GLbitfield new_state );
    258 
    259    /**
    260     * When the NewState mask intersects these masks, we invalidate the
    261     * Point/Line/Triangle function pointers below.
    262     */
    263    /*@{*/
    264    GLbitfield InvalidatePointMask;
    265    GLbitfield InvalidateLineMask;
    266    GLbitfield InvalidateTriangleMask;
    267    /*@}*/
    268 
    269    /**
    270     * Device drivers plug in functions for these callbacks.
    271     * Will be called when the GL state change mask intersects the above masks.
    272     */
    273    /*@{*/
    274    void (*choose_point)( struct gl_context * );
    275    void (*choose_line)( struct gl_context * );
    276    void (*choose_triangle)( struct gl_context * );
    277    /*@}*/
    278 
    279    /**
    280     * Current point, line and triangle drawing functions.
    281     */
    282    /*@{*/
    283    swrast_point_func Point;
    284    swrast_line_func Line;
    285    swrast_tri_func Triangle;
    286    /*@}*/
    287 
    288    /**
    289     * Placeholders for when separate specular (or secondary color) is
    290     * enabled but texturing is not.
    291     */
    292    /*@{*/
    293    swrast_point_func SpecPoint;
    294    swrast_line_func SpecLine;
    295    swrast_tri_func SpecTriangle;
    296    /*@}*/
    297 
    298    /**
    299     * Typically, we'll allocate a sw_span structure as a local variable
    300     * and set its 'array' pointer to point to this object.  The reason is
    301     * this object is big and causes problems when allocated on the stack
    302     * on some systems.
    303     */
    304    SWspanarrays *SpanArrays;
    305    SWspanarrays *ZoomedArrays;  /**< For pixel zooming */
    306 
    307    /**
    308     * Used to buffer N GL_POINTS, instead of rendering one by one.
    309     */
    310    SWspan PointSpan;
    311 
    312    /** Internal hooks, kept up to date by the same mechanism as above.
    313     */
    314    blend_func BlendFunc;
    315    texture_sample_func TextureSample[MAX_COMBINED_TEXTURE_IMAGE_UNITS];
    316 
    317    /** Buffer for saving the sampled texture colors.
    318     * Needed for GL_ARB_texture_env_crossbar implementation.
    319     */
    320    GLfloat *TexelBuffer;
    321 
    322    validate_texture_image_func ValidateTextureImage;
    323 
    324    /** State used during execution of fragment programs */
    325    struct gl_program_machine FragProgMachine;
    326 
    327    /** Temporary arrays for stencil operations.  To avoid large stack
    328     * allocations.
    329     */
    330    struct {
    331       GLubyte *buf1, *buf2, *buf3, *buf4;
    332    } stencil_temp;
    333 
    334 } SWcontext;
    335 
    336 
    337 extern void
    338 _swrast_validate_derived( struct gl_context *ctx );
    339 
    340 extern void
    341 _swrast_update_texture_samplers(struct gl_context *ctx);
    342 
    343 
    344 /** Return SWcontext for the given struct gl_context */
    345 static inline SWcontext *
    346 SWRAST_CONTEXT(struct gl_context *ctx)
    347 {
    348    return (SWcontext *) ctx->swrast_context;
    349 }
    350 
    351 /** const version of above */
    352 static inline const SWcontext *
    353 CONST_SWRAST_CONTEXT(const struct gl_context *ctx)
    354 {
    355    return (const SWcontext *) ctx->swrast_context;
    356 }
    357 
    358 
    359 /**
    360  * Called prior to framebuffer reading/writing.
    361  * For drivers that rely on swrast for fallback rendering, this is the
    362  * driver's opportunity to map renderbuffers and textures.
    363  */
    364 static inline void
    365 swrast_render_start(struct gl_context *ctx)
    366 {
    367    SWcontext *swrast = SWRAST_CONTEXT(ctx);
    368    if (swrast->Driver.SpanRenderStart)
    369       swrast->Driver.SpanRenderStart(ctx);
    370 }
    371 
    372 
    373 /** Called after framebuffer reading/writing */
    374 static inline void
    375 swrast_render_finish(struct gl_context *ctx)
    376 {
    377    SWcontext *swrast = SWRAST_CONTEXT(ctx);
    378    if (swrast->Driver.SpanRenderFinish)
    379       swrast->Driver.SpanRenderFinish(ctx);
    380 }
    381 
    382 
    383 extern void
    384 _swrast_span_render_start(struct gl_context *ctx);
    385 
    386 extern void
    387 _swrast_span_render_finish(struct gl_context *ctx);
    388 
    389 extern void
    390 _swrast_map_textures(struct gl_context *ctx);
    391 
    392 extern void
    393 _swrast_unmap_textures(struct gl_context *ctx);
    394 
    395 extern unsigned int
    396 _swrast_teximage_slice_height(struct gl_texture_image *texImage);
    397 
    398 extern void
    399 _swrast_map_texture(struct gl_context *ctx, struct gl_texture_object *texObj);
    400 
    401 extern void
    402 _swrast_unmap_texture(struct gl_context *ctx, struct gl_texture_object *texObj);
    403 
    404 
    405 extern void
    406 _swrast_map_renderbuffers(struct gl_context *ctx);
    407 
    408 extern void
    409 _swrast_unmap_renderbuffers(struct gl_context *ctx);
    410 
    411 
    412 /**
    413  * Size of an RGBA pixel, in bytes, for given datatype.
    414  */
    415 #define RGBA_PIXEL_SIZE(TYPE)                                     \
    416          ((TYPE == GL_UNSIGNED_BYTE) ? 4 * sizeof(GLubyte) :      \
    417           ((TYPE == GL_UNSIGNED_SHORT) ? 4 * sizeof(GLushort)     \
    418            : 4 * sizeof(GLfloat)))
    419 
    420 
    421 
    422 /*
    423  * Fixed point arithmetic macros
    424  */
    425 #ifndef FIXED_FRAC_BITS
    426 #define FIXED_FRAC_BITS 11
    427 #endif
    428 
    429 #define FIXED_SHIFT     FIXED_FRAC_BITS
    430 #define FIXED_ONE       (1 << FIXED_SHIFT)
    431 #define FIXED_HALF      (1 << (FIXED_SHIFT-1))
    432 #define FIXED_FRAC_MASK (FIXED_ONE - 1)
    433 #define FIXED_INT_MASK  (~FIXED_FRAC_MASK)
    434 #define FIXED_EPSILON   1
    435 #define FIXED_SCALE     ((float) FIXED_ONE)
    436 #define FIXED_DBL_SCALE ((double) FIXED_ONE)
    437 #define FloatToFixed(X) (IROUND((X) * FIXED_SCALE))
    438 #define FixedToDouble(X) ((X) * (1.0 / FIXED_DBL_SCALE))
    439 #define IntToFixed(I)   ((I) << FIXED_SHIFT)
    440 #define FixedToInt(X)   ((X) >> FIXED_SHIFT)
    441 #define FixedToUns(X)   (((unsigned int)(X)) >> FIXED_SHIFT)
    442 #define FixedCeil(X)    (((X) + FIXED_ONE - FIXED_EPSILON) & FIXED_INT_MASK)
    443 #define FixedFloor(X)   ((X) & FIXED_INT_MASK)
    444 #define FixedToFloat(X) ((X) * (1.0F / FIXED_SCALE))
    445 #define PosFloatToFixed(X)      FloatToFixed(X)
    446 #define SignedFloatToFixed(X)   FloatToFixed(X)
    447 
    448 
    449 
    450 /*
    451  * XXX these macros are just bandages for now in order to make
    452  * CHAN_BITS==32 compile cleanly.
    453  * These should probably go elsewhere at some point.
    454  */
    455 #if CHAN_TYPE == GL_FLOAT
    456 #define ChanToFixed(X)  (X)
    457 #define FixedToChan(X)  (X)
    458 #else
    459 #define ChanToFixed(X)  IntToFixed(X)
    460 #define FixedToChan(X)  FixedToInt(X)
    461 #endif
    462 
    463 
    464 /**
    465  * For looping over fragment attributes in the pointe, line
    466  * triangle rasterizers.
    467  */
    468 #define ATTRIB_LOOP_BEGIN                                \
    469    {                                                     \
    470       GLuint a;                                          \
    471       for (a = 0; a < swrast->_NumActiveAttribs; a++) {  \
    472          const GLuint attr = swrast->_ActiveAttribs[a];
    473 
    474 #define ATTRIB_LOOP_END } }
    475 
    476 
    477 /**
    478  * Return the address of a pixel value in a mapped renderbuffer.
    479  */
    480 static inline GLubyte *
    481 _swrast_pixel_address(struct gl_renderbuffer *rb, GLint x, GLint y)
    482 {
    483    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
    484    const GLint bpp = _mesa_get_format_bytes(rb->Format);
    485    const GLint rowStride = srb->RowStride;
    486    assert(x >= 0);
    487    assert(y >= 0);
    488    /* NOTE: using <= only because of s_tritemp.h which gets a pixel
    489     * address but doesn't necessarily access it.
    490     */
    491    assert(x <= (GLint) rb->Width);
    492    assert(y <= (GLint) rb->Height);
    493    assert(srb->Map);
    494    return (GLubyte *) srb->Map + y * rowStride + x * bpp;
    495 }
    496 
    497 
    498 
    499 #endif
    500