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      1 /**************************************************************************
      2  *
      3  * Copyright 2007 VMware, Inc.
      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 VMWARE 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/feedback.h"
     42 #include "main/rastpos.h"
     43 
     44 #include "st_context.h"
     45 #include "st_atom.h"
     46 #include "st_draw.h"
     47 #include "st_program.h"
     48 #include "st_cb_rasterpos.h"
     49 #include "draw/draw_context.h"
     50 #include "draw/draw_pipe.h"
     51 #include "vbo/vbo.h"
     52 
     53 
     54 /**
     55  * Our special drawing pipeline stage (replaces rasterization).
     56  */
     57 struct rastpos_stage
     58 {
     59    struct draw_stage stage;   /**< Base class */
     60    struct gl_context *ctx;            /**< Rendering context */
     61 
     62    /* vertex attrib info we can setup once and re-use */
     63    struct gl_vertex_array array[VERT_ATTRIB_MAX];
     64    const struct gl_vertex_array *arrays[VERT_ATTRIB_MAX];
     65    struct _mesa_prim prim;
     66 };
     67 
     68 
     69 static inline struct rastpos_stage *
     70 rastpos_stage( struct draw_stage *stage )
     71 {
     72    return (struct rastpos_stage *) stage;
     73 }
     74 
     75 static void
     76 rastpos_flush( struct draw_stage *stage, unsigned flags )
     77 {
     78    /* no-op */
     79 }
     80 
     81 static void
     82 rastpos_reset_stipple_counter( struct draw_stage *stage )
     83 {
     84    /* no-op */
     85 }
     86 
     87 static void
     88 rastpos_tri( struct draw_stage *stage, struct prim_header *prim )
     89 {
     90    /* should never get here */
     91    assert(0);
     92 }
     93 
     94 static void
     95 rastpos_line( struct draw_stage *stage, struct prim_header *prim )
     96 {
     97    /* should never get here */
     98    assert(0);
     99 }
    100 
    101 static void
    102 rastpos_destroy(struct draw_stage *stage)
    103 {
    104    free(stage);
    105 }
    106 
    107 
    108 /**
    109  * Update a raster pos attribute from the vertex result if it's present,
    110  * else copy the current attrib.
    111  */
    112 static void
    113 update_attrib(struct gl_context *ctx, const ubyte *outputMapping,
    114               const struct vertex_header *vert,
    115               GLfloat *dest,
    116               GLuint result, GLuint defaultAttrib)
    117 {
    118    const GLfloat *src;
    119    const GLuint k = outputMapping[result];
    120    if (k != ~0U)
    121       src = vert->data[k];
    122    else
    123       src = ctx->Current.Attrib[defaultAttrib];
    124    COPY_4V(dest, src);
    125 }
    126 
    127 
    128 /**
    129  * Normally, this function would render a GL_POINT.
    130  */
    131 static void
    132 rastpos_point(struct draw_stage *stage, struct prim_header *prim)
    133 {
    134    struct rastpos_stage *rs = rastpos_stage(stage);
    135    struct gl_context *ctx = rs->ctx;
    136    struct st_context *st = st_context(ctx);
    137    const GLfloat height = (GLfloat) ctx->DrawBuffer->Height;
    138    const ubyte *outputMapping = st->vp->result_to_output;
    139    const GLfloat *pos;
    140    GLuint i;
    141 
    142    /* if we get here, we didn't get clipped */
    143    ctx->Current.RasterPosValid = GL_TRUE;
    144 
    145    /* update raster pos */
    146    pos = prim->v[0]->data[0];
    147    ctx->Current.RasterPos[0] = pos[0];
    148    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
    149       ctx->Current.RasterPos[1] = height - pos[1]; /* invert Y */
    150    else
    151       ctx->Current.RasterPos[1] = pos[1];
    152    ctx->Current.RasterPos[2] = pos[2];
    153    ctx->Current.RasterPos[3] = pos[3];
    154 
    155    /* update other raster attribs */
    156    update_attrib(ctx, outputMapping, prim->v[0],
    157                  ctx->Current.RasterColor,
    158                  VARYING_SLOT_COL0, VERT_ATTRIB_COLOR0);
    159 
    160    update_attrib(ctx, outputMapping, prim->v[0],
    161                  ctx->Current.RasterSecondaryColor,
    162                  VARYING_SLOT_COL1, VERT_ATTRIB_COLOR1);
    163 
    164    for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
    165       update_attrib(ctx, outputMapping, prim->v[0],
    166                     ctx->Current.RasterTexCoords[i],
    167                     VARYING_SLOT_TEX0 + i, VERT_ATTRIB_TEX0 + i);
    168    }
    169 
    170    if (ctx->RenderMode == GL_SELECT) {
    171       _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
    172    }
    173 }
    174 
    175 
    176 /**
    177  * Create rasterpos "drawing" stage.
    178  */
    179 static struct rastpos_stage *
    180 new_draw_rastpos_stage(struct gl_context *ctx, struct draw_context *draw)
    181 {
    182    struct rastpos_stage *rs = ST_CALLOC_STRUCT(rastpos_stage);
    183    GLuint i;
    184 
    185    rs->stage.draw = draw;
    186    rs->stage.next = NULL;
    187    rs->stage.point = rastpos_point;
    188    rs->stage.line = rastpos_line;
    189    rs->stage.tri = rastpos_tri;
    190    rs->stage.flush = rastpos_flush;
    191    rs->stage.destroy = rastpos_destroy;
    192    rs->stage.reset_stipple_counter = rastpos_reset_stipple_counter;
    193    rs->stage.destroy = rastpos_destroy;
    194    rs->ctx = ctx;
    195 
    196    for (i = 0; i < ARRAY_SIZE(rs->array); i++) {
    197       rs->array[i].Size = 4;
    198       rs->array[i].Type = GL_FLOAT;
    199       rs->array[i].Format = GL_RGBA;
    200       rs->array[i].StrideB = 0;
    201       rs->array[i].Ptr = (GLubyte *) ctx->Current.Attrib[i];
    202       rs->array[i].Normalized = GL_TRUE;
    203       rs->array[i].BufferObj = NULL;
    204       rs->arrays[i] = &rs->array[i];
    205    }
    206 
    207    rs->prim.mode = GL_POINTS;
    208    rs->prim.indexed = 0;
    209    rs->prim.begin = 1;
    210    rs->prim.end = 1;
    211    rs->prim.weak = 0;
    212    rs->prim.start = 0;
    213    rs->prim.count = 1;
    214 
    215    return rs;
    216 }
    217 
    218 
    219 static void
    220 st_RasterPos(struct gl_context *ctx, const GLfloat v[4])
    221 {
    222    struct st_context *st = st_context(ctx);
    223    struct draw_context *draw = st_get_draw_context(st);
    224    struct rastpos_stage *rs;
    225    const struct gl_vertex_array **saved_arrays = ctx->Array._DrawArrays;
    226 
    227    if (!st->draw)
    228       return;
    229 
    230    if (ctx->VertexProgram._Current == NULL ||
    231        ctx->VertexProgram._Current == ctx->VertexProgram._TnlProgram) {
    232       /* No vertex shader/program is enabled, used the simple/fast fixed-
    233        * function implementation of RasterPos.
    234        */
    235       _mesa_RasterPos(ctx, v);
    236       return;
    237    }
    238 
    239    if (st->rastpos_stage) {
    240       /* get rastpos stage info */
    241       rs = rastpos_stage(st->rastpos_stage);
    242    }
    243    else {
    244       /* create rastpos draw stage */
    245       rs = new_draw_rastpos_stage(ctx, draw);
    246       st->rastpos_stage = &rs->stage;
    247    }
    248 
    249    /* plug our rastpos stage into the draw module */
    250    draw_set_rasterize_stage(st->draw, st->rastpos_stage);
    251 
    252    /* make sure everything's up to date */
    253    st_validate_state(st, ST_PIPELINE_RENDER);
    254 
    255    /* This will get set only if rastpos_point(), above, gets called */
    256    ctx->Current.RasterPosValid = GL_FALSE;
    257 
    258    /* All vertex attribs but position were previously initialized above.
    259     * Just plug in position pointer now.
    260     */
    261    rs->array[0].Ptr = (GLubyte *) v;
    262 
    263    /* Draw the point.
    264     *
    265     * Don't set DriverFlags.NewArray.
    266     * st_feedback_draw_vbo doesn't check for that flag. */
    267    ctx->Array._DrawArrays = rs->arrays;
    268    st_feedback_draw_vbo(ctx, &rs->prim, 1, NULL, GL_TRUE, 0, 1,
    269                         NULL, 0, NULL);
    270    ctx->Array._DrawArrays = saved_arrays;
    271 
    272    /* restore draw's rasterization stage depending on rendermode */
    273    if (ctx->RenderMode == GL_FEEDBACK) {
    274       draw_set_rasterize_stage(draw, st->feedback_stage);
    275    }
    276    else if (ctx->RenderMode == GL_SELECT) {
    277       draw_set_rasterize_stage(draw, st->selection_stage);
    278    }
    279 }
    280 
    281 
    282 
    283 void st_init_rasterpos_functions(struct dd_function_table *functions)
    284 {
    285    functions->RasterPos = st_RasterPos;
    286 }
    287