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      1 /**************************************************************************
      2  *
      3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
      4  * 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
      8  * "Software"), to deal in the Software without restriction, including
      9  * without limitation the rights to use, copy, modify, merge, publish,
     10  * distribute, sub license, and/or sell copies of the Software, and to
     11  * permit persons to whom the Software is furnished to do so, subject to
     12  * the following conditions:
     13  *
     14  * The above copyright notice and this permission notice (including the
     15  * next paragraph) shall be included in all copies or substantial portions
     16  * of the Software.
     17  *
     18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
     21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
     22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
     23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
     24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     25  *
     26  **************************************************************************/
     27 
     28 /**
     29  * glRasterPos implementation.  Basically render a GL_POINT with our
     30  * private draw module.  Plug in a special "rasterpos" stage at the end
     31  * of the 'draw' pipeline to capture the results and update the current
     32  * raster pos attributes.
     33  *
     34  * Authors:
     35  *   Brian Paul
     36  */
     37 
     38 
     39 #include "main/imports.h"
     40 #include "main/macros.h"
     41 #include "main/mfeatures.h"
     42 #include "main/feedback.h"
     43 
     44 #include "st_context.h"
     45 #include "st_atom.h"
     46 #include "st_draw.h"
     47 #include "st_cb_rasterpos.h"
     48 #include "draw/draw_context.h"
     49 #include "draw/draw_pipe.h"
     50 #include "vbo/vbo.h"
     51 
     52 
     53 #if FEATURE_rastpos
     54 
     55 /**
     56  * Our special drawing pipeline stage (replaces rasterization).
     57  */
     58 struct rastpos_stage
     59 {
     60    struct draw_stage stage;   /**< Base class */
     61    struct gl_context *ctx;            /**< Rendering context */
     62 
     63    /* vertex attrib info we can setup once and re-use */
     64    struct gl_client_array array[VERT_ATTRIB_MAX];
     65    const struct gl_client_array *arrays[VERT_ATTRIB_MAX];
     66    struct _mesa_prim prim;
     67 };
     68 
     69 
     70 static INLINE struct rastpos_stage *
     71 rastpos_stage( struct draw_stage *stage )
     72 {
     73    return (struct rastpos_stage *) stage;
     74 }
     75 
     76 static void
     77 rastpos_flush( struct draw_stage *stage, unsigned flags )
     78 {
     79    /* no-op */
     80 }
     81 
     82 static void
     83 rastpos_reset_stipple_counter( struct draw_stage *stage )
     84 {
     85    /* no-op */
     86 }
     87 
     88 static void
     89 rastpos_tri( struct draw_stage *stage, struct prim_header *prim )
     90 {
     91    /* should never get here */
     92    assert(0);
     93 }
     94 
     95 static void
     96 rastpos_line( struct draw_stage *stage, struct prim_header *prim )
     97 {
     98    /* should never get here */
     99    assert(0);
    100 }
    101 
    102 static void
    103 rastpos_destroy(struct draw_stage *stage)
    104 {
    105    free(stage);
    106 }
    107 
    108 
    109 /**
    110  * Update a raster pos attribute from the vertex result if it's present,
    111  * else copy the current attrib.
    112  */
    113 static void
    114 update_attrib(struct gl_context *ctx, const GLuint *outputMapping,
    115               const struct vertex_header *vert,
    116               GLfloat *dest,
    117               GLuint result, GLuint defaultAttrib)
    118 {
    119    const GLfloat *src;
    120    const GLuint k = outputMapping[result];
    121    if (k != ~0U)
    122       src = vert->data[k];
    123    else
    124       src = ctx->Current.Attrib[defaultAttrib];
    125    COPY_4V(dest, src);
    126 }
    127 
    128 
    129 /**
    130  * Normally, this function would render a GL_POINT.
    131  */
    132 static void
    133 rastpos_point(struct draw_stage *stage, struct prim_header *prim)
    134 {
    135    struct rastpos_stage *rs = rastpos_stage(stage);
    136    struct gl_context *ctx = rs->ctx;
    137    struct st_context *st = st_context(ctx);
    138    const GLfloat height = (GLfloat) ctx->DrawBuffer->Height;
    139    const GLuint *outputMapping = st->vertex_result_to_slot;
    140    const GLfloat *pos;
    141    GLuint i;
    142 
    143    /* if we get here, we didn't get clipped */
    144    ctx->Current.RasterPosValid = GL_TRUE;
    145 
    146    /* update raster pos */
    147    pos = prim->v[0]->data[0];
    148    ctx->Current.RasterPos[0] = pos[0];
    149    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
    150       ctx->Current.RasterPos[1] = height - pos[1]; /* invert Y */
    151    else
    152       ctx->Current.RasterPos[1] = pos[1];
    153    ctx->Current.RasterPos[2] = pos[2];
    154    ctx->Current.RasterPos[3] = pos[3];
    155 
    156    /* update other raster attribs */
    157    update_attrib(ctx, outputMapping, prim->v[0],
    158                  ctx->Current.RasterColor,
    159                  VERT_RESULT_COL0, VERT_ATTRIB_COLOR0);
    160 
    161    update_attrib(ctx, outputMapping, prim->v[0],
    162                  ctx->Current.RasterSecondaryColor,
    163                  VERT_RESULT_COL1, VERT_ATTRIB_COLOR1);
    164 
    165    for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
    166       update_attrib(ctx, outputMapping, prim->v[0],
    167                     ctx->Current.RasterTexCoords[i],
    168                     VERT_RESULT_TEX0 + i, VERT_ATTRIB_TEX0 + i);
    169    }
    170 
    171    if (ctx->RenderMode == GL_SELECT) {
    172       _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
    173    }
    174 }
    175 
    176 
    177 /**
    178  * Create rasterpos "drawing" stage.
    179  */
    180 static struct rastpos_stage *
    181 new_draw_rastpos_stage(struct gl_context *ctx, struct draw_context *draw)
    182 {
    183    struct rastpos_stage *rs = ST_CALLOC_STRUCT(rastpos_stage);
    184    GLuint i;
    185 
    186    rs->stage.draw = draw;
    187    rs->stage.next = NULL;
    188    rs->stage.point = rastpos_point;
    189    rs->stage.line = rastpos_line;
    190    rs->stage.tri = rastpos_tri;
    191    rs->stage.flush = rastpos_flush;
    192    rs->stage.destroy = rastpos_destroy;
    193    rs->stage.reset_stipple_counter = rastpos_reset_stipple_counter;
    194    rs->stage.destroy = rastpos_destroy;
    195    rs->ctx = ctx;
    196 
    197    for (i = 0; i < Elements(rs->array); i++) {
    198       rs->array[i].Size = 4;
    199       rs->array[i].Type = GL_FLOAT;
    200       rs->array[i].Format = GL_RGBA;
    201       rs->array[i].Stride = 0;
    202       rs->array[i].StrideB = 0;
    203       rs->array[i].Ptr = (GLubyte *) ctx->Current.Attrib[i];
    204       rs->array[i].Enabled = GL_TRUE;
    205       rs->array[i].Normalized = GL_TRUE;
    206       rs->array[i].BufferObj = NULL;
    207       rs->arrays[i] = &rs->array[i];
    208    }
    209 
    210    rs->prim.mode = GL_POINTS;
    211    rs->prim.indexed = 0;
    212    rs->prim.begin = 1;
    213    rs->prim.end = 1;
    214    rs->prim.weak = 0;
    215    rs->prim.start = 0;
    216    rs->prim.count = 1;
    217 
    218    return rs;
    219 }
    220 
    221 
    222 static void
    223 st_RasterPos(struct gl_context *ctx, const GLfloat v[4])
    224 {
    225    struct st_context *st = st_context(ctx);
    226    struct draw_context *draw = st->draw;
    227    struct rastpos_stage *rs;
    228    const struct gl_client_array **saved_arrays = ctx->Array._DrawArrays;
    229 
    230    if (st->rastpos_stage) {
    231       /* get rastpos stage info */
    232       rs = rastpos_stage(st->rastpos_stage);
    233    }
    234    else {
    235       /* create rastpos draw stage */
    236       rs = new_draw_rastpos_stage(ctx, draw);
    237       st->rastpos_stage = &rs->stage;
    238    }
    239 
    240    /* plug our rastpos stage into the draw module */
    241    draw_set_rasterize_stage(st->draw, st->rastpos_stage);
    242 
    243    /* make sure everything's up to date */
    244    st_validate_state(st);
    245 
    246    /* This will get set only if rastpos_point(), above, gets called */
    247    ctx->Current.RasterPosValid = GL_FALSE;
    248 
    249    /* All vertex attribs but position were previously initialized above.
    250     * Just plug in position pointer now.
    251     */
    252    rs->array[0].Ptr = (GLubyte *) v;
    253 
    254    /* Draw the point.
    255     *
    256     * Don't set DriverFlags.NewArray.
    257     * st_feedback_draw_vbo doesn't check for that flag. */
    258    ctx->Array._DrawArrays = rs->arrays;
    259    st_feedback_draw_vbo(ctx, &rs->prim, 1, NULL, GL_TRUE, 0, 1,
    260                         NULL);
    261    ctx->Array._DrawArrays = saved_arrays;
    262 
    263    /* restore draw's rasterization stage depending on rendermode */
    264    if (ctx->RenderMode == GL_FEEDBACK) {
    265       draw_set_rasterize_stage(draw, st->feedback_stage);
    266    }
    267    else if (ctx->RenderMode == GL_SELECT) {
    268       draw_set_rasterize_stage(draw, st->selection_stage);
    269    }
    270 }
    271 
    272 
    273 
    274 void st_init_rasterpos_functions(struct dd_function_table *functions)
    275 {
    276    functions->RasterPos = st_RasterPos;
    277 }
    278 
    279 #endif /* FEATURE_rastpos */
    280