src/mesa/state_tracker/st_cb_rasterpos.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 VMware, Inc.
   4  * All Rights Reserved.
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   7  * copy of this software and associated documentation files (the
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  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
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  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 }