src/mesa/state_tracker/st_cb_feedback.c

   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
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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
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  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
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  25  *
  26  **************************************************************************/
  27
  28 /**
  29  * GL_SELECT and GL_FEEDBACK render modes.
  30  * Basically, we use a private instance of the 'draw' module for doing
  31  * selection/feedback.  It would be nice to use the transform_feedback
  32  * hardware feature, but it's defined as happening pre-clip and we want
  33  * post-clipped primitives.  Also, there's concerns about the efficiency
  34  * of using the hardware for this anyway.
  35  *
  36  * Authors:
  37  *   Brian Paul
  38  */
  39
  40 #include "util/imports.h"
  41 #include "main/context.h"
  42 #include "main/feedback.h"
  43 #include "main/varray.h"
  44
  45 #include "vbo/vbo.h"
  46
  47 #include "st_context.h"
  48 #include "st_draw.h"
  49 #include "st_cb_feedback.h"
  50 #include "st_program.h"
  51 #include "st_util.h"
  52
  53 #include "pipe/p_context.h"
  54 #include "pipe/p_defines.h"
  55
  56 #include "draw/draw_context.h"
  57 #include "draw/draw_pipe.h"
  58
  59
  60 /**
  61  * This is actually used for both feedback and selection.
  62  */
  63 struct feedback_stage
  64 {
  65    struct draw_stage stage;   /**< Base class */
  66    struct gl_context *ctx;            /**< Rendering context */
  67    GLboolean reset_stipple_counter;
  68 };
  69
  70
  71 /**********************************************************************
  72  * GL Feedback functions
  73  **********************************************************************/
  74
  75 static inline struct feedback_stage *
  76 feedback_stage( struct draw_stage *stage )
  77 {
  78    return (struct feedback_stage *)stage;
  79 }
  80
  81
  82 static void
  83 feedback_vertex(struct gl_context *ctx, const struct draw_context *draw,
  84                 const struct vertex_header *v)
  85 {
  86    const struct st_context *st = st_context(ctx);
  87    struct st_vertex_program *stvp = (struct st_vertex_program *)st->vp;
  88    GLfloat win[4];
  89    const GLfloat *color, *texcoord;
  90    GLuint slot;
  91
  92    win[0] = v->data[0][0];
  93    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
  94       win[1] = ctx->DrawBuffer->Height - v->data[0][1];
  95    else
  96       win[1] = v->data[0][1];
  97    win[2] = v->data[0][2];
  98    win[3] = 1.0F / v->data[0][3];
  99
 100    /* XXX
 101     * When we compute vertex layout, save info about position of the
 102     * color and texcoord attribs to use here.
 103     */
 104
 105    slot = stvp->result_to_output[VARYING_SLOT_COL0];
 106    if (slot != ~0U)
 107       color = v->data[slot];
 108    else
 109       color = ctx->Current.Attrib[VERT_ATTRIB_COLOR0];
 110
 111    slot = stvp->result_to_output[VARYING_SLOT_TEX0];
 112    if (slot != ~0U)
 113       texcoord = v->data[slot];
 114    else
 115       texcoord = ctx->Current.Attrib[VERT_ATTRIB_TEX0];
 116
 117    _mesa_feedback_vertex(ctx, win, color, texcoord);
 118 }
 119
 120
 121 static void
 122 feedback_tri( struct draw_stage *stage, struct prim_header *prim )
 123 {
 124    struct feedback_stage *fs = feedback_stage(stage);
 125    struct draw_context *draw = stage->draw;
 126    _mesa_feedback_token(fs->ctx, (GLfloat) GL_POLYGON_TOKEN);
 127    _mesa_feedback_token(fs->ctx, (GLfloat) 3); /* three vertices */
 128    feedback_vertex(fs->ctx, draw, prim->v[0]);
 129    feedback_vertex(fs->ctx, draw, prim->v[1]);
 130    feedback_vertex(fs->ctx, draw, prim->v[2]);
 131 }
 132
 133
 134 static void
 135 feedback_line( struct draw_stage *stage, struct prim_header *prim )
 136 {
 137    struct feedback_stage *fs = feedback_stage(stage);
 138    struct draw_context *draw = stage->draw;
 139    if (fs->reset_stipple_counter) {
 140       _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_RESET_TOKEN);
 141       fs->reset_stipple_counter = GL_FALSE;
 142    }
 143    else {
 144       _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_TOKEN);
 145    }
 146    feedback_vertex(fs->ctx, draw, prim->v[0]);
 147    feedback_vertex(fs->ctx, draw, prim->v[1]);
 148 }
 149
 150
 151 static void
 152 feedback_point( struct draw_stage *stage, struct prim_header *prim )
 153 {
 154    struct feedback_stage *fs = feedback_stage(stage);
 155    struct draw_context *draw = stage->draw;
 156    _mesa_feedback_token(fs->ctx, (GLfloat) GL_POINT_TOKEN);
 157    feedback_vertex(fs->ctx, draw, prim->v[0]);
 158 }
 159
 160
 161 static void
 162 feedback_flush( struct draw_stage *stage, unsigned flags )
 163 {
 164    /* no-op */
 165 }
 166
 167
 168 static void
 169 feedback_reset_stipple_counter( struct draw_stage *stage )
 170 {
 171    struct feedback_stage *fs = feedback_stage(stage);
 172    fs->reset_stipple_counter = GL_TRUE;
 173 }
 174
 175
 176 static void
 177 feedback_destroy( struct draw_stage *stage )
 178 {
 179    free(stage);
 180 }
 181
 182 /**
 183  * Create GL feedback drawing stage.
 184  */
 185 static struct draw_stage *
 186 draw_glfeedback_stage(struct gl_context *ctx, struct draw_context *draw)
 187 {
 188    struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
 189
 190    fs->stage.draw = draw;
 191    fs->stage.next = NULL;
 192    fs->stage.point = feedback_point;
 193    fs->stage.line = feedback_line;
 194    fs->stage.tri = feedback_tri;
 195    fs->stage.flush = feedback_flush;
 196    fs->stage.reset_stipple_counter = feedback_reset_stipple_counter;
 197    fs->stage.destroy = feedback_destroy;
 198    fs->ctx = ctx;
 199
 200    return &fs->stage;
 201 }
 202
 203
 204
 205 /**********************************************************************
 206  * GL Selection functions
 207  **********************************************************************/
 208
 209 static void
 210 select_tri( struct draw_stage *stage, struct prim_header *prim )
 211 {
 212    struct feedback_stage *fs = feedback_stage(stage);
 213    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 214    _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
 215    _mesa_update_hitflag( fs->ctx, prim->v[2]->data[0][2] );
 216 }
 217
 218 static void
 219 select_line( struct draw_stage *stage, struct prim_header *prim )
 220 {
 221    struct feedback_stage *fs = feedback_stage(stage);
 222    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 223    _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
 224 }
 225
 226
 227 static void
 228 select_point( struct draw_stage *stage, struct prim_header *prim )
 229 {
 230    struct feedback_stage *fs = feedback_stage(stage);
 231    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 232 }
 233
 234
 235 static void
 236 select_flush( struct draw_stage *stage, unsigned flags )
 237 {
 238    /* no-op */
 239 }
 240
 241
 242 static void
 243 select_reset_stipple_counter( struct draw_stage *stage )
 244 {
 245    /* no-op */
 246 }
 247
 248 static void
 249 select_destroy( struct draw_stage *stage )
 250 {
 251    free(stage);
 252 }
 253
 254
 255 /**
 256  * Create GL selection mode drawing stage.
 257  */
 258 static struct draw_stage *
 259 draw_glselect_stage(struct gl_context *ctx, struct draw_context *draw)
 260 {
 261    struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
 262
 263    fs->stage.draw = draw;
 264    fs->stage.next = NULL;
 265    fs->stage.point = select_point;
 266    fs->stage.line = select_line;
 267    fs->stage.tri = select_tri;
 268    fs->stage.flush = select_flush;
 269    fs->stage.reset_stipple_counter = select_reset_stipple_counter;
 270    fs->stage.destroy = select_destroy;
 271    fs->ctx = ctx;
 272
 273    return &fs->stage;
 274 }
 275
 276
 277 static void
 278 st_RenderMode(struct gl_context *ctx, GLenum newMode )
 279 {
 280    struct st_context *st = st_context(ctx);
 281    struct draw_context *draw = st_get_draw_context(st);
 282
 283    if (!st->draw)
 284       return;
 285
 286    if (newMode == GL_RENDER) {
 287       /* restore normal VBO draw function */
 288       st_init_draw_functions(&ctx->Driver);
 289    }
 290    else if (newMode == GL_SELECT) {
 291       if (!st->selection_stage)
 292          st->selection_stage = draw_glselect_stage(ctx, draw);
 293       draw_set_rasterize_stage(draw, st->selection_stage);
 294       /* Plug in new vbo draw function */
 295       ctx->Driver.Draw = st_feedback_draw_vbo;
 296    }
 297    else {
 298       struct gl_program *vp = st->ctx->VertexProgram._Current;
 299
 300       if (!st->feedback_stage)
 301          st->feedback_stage = draw_glfeedback_stage(ctx, draw);
 302       draw_set_rasterize_stage(draw, st->feedback_stage);
 303       /* Plug in new vbo draw function */
 304       ctx->Driver.Draw = st_feedback_draw_vbo;
 305       /* need to generate/use a vertex program that emits pos/color/tex */
 306       if (vp)
 307          st->dirty |= ST_NEW_VERTEX_PROGRAM(st, st_program(vp));
 308    }
 309 }
 310
 311
 312
 313 void st_init_feedback_functions(struct dd_function_table *functions)
 314 {
 315    functions->RenderMode = st_RenderMode;
 316 }