src/mesa/state_tracker/st_cb_feedback.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 VMware, Inc.
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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
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  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
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  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 "main/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    GLfloat win[4];
  88    const GLfloat *color, *texcoord;
  89    GLuint slot;
  90
  91    win[0] = v->data[0][0];
  92    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
  93       win[1] = ctx->DrawBuffer->Height - v->data[0][1];
  94    else
  95       win[1] = v->data[0][1];
  96    win[2] = v->data[0][2];
  97    win[3] = 1.0F / v->data[0][3];
  98
  99    /* XXX
 100     * When we compute vertex layout, save info about position of the
 101     * color and texcoord attribs to use here.
 102     */
 103
 104    slot = st->vp->result_to_output[VARYING_SLOT_COL0];
 105    if (slot != ~0U)
 106       color = v->data[slot];
 107    else
 108       color = ctx->Current.Attrib[VERT_ATTRIB_COLOR0];
 109
 110    slot = st->vp->result_to_output[VARYING_SLOT_TEX0];
 111    if (slot != ~0U)
 112       texcoord = v->data[slot];
 113    else
 114       texcoord = ctx->Current.Attrib[VERT_ATTRIB_TEX0];
 115
 116    _mesa_feedback_vertex(ctx, win, color, texcoord);
 117 }
 118
 119
 120 static void
 121 feedback_tri( struct draw_stage *stage, struct prim_header *prim )
 122 {
 123    struct feedback_stage *fs = feedback_stage(stage);
 124    struct draw_context *draw = stage->draw;
 125    _mesa_feedback_token(fs->ctx, (GLfloat) GL_POLYGON_TOKEN);
 126    _mesa_feedback_token(fs->ctx, (GLfloat) 3); /* three vertices */
 127    feedback_vertex(fs->ctx, draw, prim->v[0]);
 128    feedback_vertex(fs->ctx, draw, prim->v[1]);
 129    feedback_vertex(fs->ctx, draw, prim->v[2]);
 130 }
 131
 132
 133 static void
 134 feedback_line( struct draw_stage *stage, struct prim_header *prim )
 135 {
 136    struct feedback_stage *fs = feedback_stage(stage);
 137    struct draw_context *draw = stage->draw;
 138    if (fs->reset_stipple_counter) {
 139       _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_RESET_TOKEN);
 140       fs->reset_stipple_counter = GL_FALSE;
 141    }
 142    else {
 143       _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_TOKEN);
 144    }
 145    feedback_vertex(fs->ctx, draw, prim->v[0]);
 146    feedback_vertex(fs->ctx, draw, prim->v[1]);
 147 }
 148
 149
 150 static void
 151 feedback_point( struct draw_stage *stage, struct prim_header *prim )
 152 {
 153    struct feedback_stage *fs = feedback_stage(stage);
 154    struct draw_context *draw = stage->draw;
 155    _mesa_feedback_token(fs->ctx, (GLfloat) GL_POINT_TOKEN);
 156    feedback_vertex(fs->ctx, draw, prim->v[0]);
 157 }
 158
 159
 160 static void
 161 feedback_flush( struct draw_stage *stage, unsigned flags )
 162 {
 163    /* no-op */
 164 }
 165
 166
 167 static void
 168 feedback_reset_stipple_counter( struct draw_stage *stage )
 169 {
 170    struct feedback_stage *fs = feedback_stage(stage);
 171    fs->reset_stipple_counter = GL_TRUE;
 172 }
 173
 174
 175 static void
 176 feedback_destroy( struct draw_stage *stage )
 177 {
 178    free(stage);
 179 }
 180
 181 /**
 182  * Create GL feedback drawing stage.
 183  */
 184 static struct draw_stage *
 185 draw_glfeedback_stage(struct gl_context *ctx, struct draw_context *draw)
 186 {
 187    struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
 188
 189    fs->stage.draw = draw;
 190    fs->stage.next = NULL;
 191    fs->stage.point = feedback_point;
 192    fs->stage.line = feedback_line;
 193    fs->stage.tri = feedback_tri;
 194    fs->stage.flush = feedback_flush;
 195    fs->stage.reset_stipple_counter = feedback_reset_stipple_counter;
 196    fs->stage.destroy = feedback_destroy;
 197    fs->ctx = ctx;
 198
 199    return &fs->stage;
 200 }
 201
 202
 203
 204 /**********************************************************************
 205  * GL Selection functions
 206  **********************************************************************/
 207
 208 static void
 209 select_tri( struct draw_stage *stage, struct prim_header *prim )
 210 {
 211    struct feedback_stage *fs = feedback_stage(stage);
 212    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 213    _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
 214    _mesa_update_hitflag( fs->ctx, prim->v[2]->data[0][2] );
 215 }
 216
 217 static void
 218 select_line( struct draw_stage *stage, struct prim_header *prim )
 219 {
 220    struct feedback_stage *fs = feedback_stage(stage);
 221    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 222    _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
 223 }
 224
 225
 226 static void
 227 select_point( struct draw_stage *stage, struct prim_header *prim )
 228 {
 229    struct feedback_stage *fs = feedback_stage(stage);
 230    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 231 }
 232
 233
 234 static void
 235 select_flush( struct draw_stage *stage, unsigned flags )
 236 {
 237    /* no-op */
 238 }
 239
 240
 241 static void
 242 select_reset_stipple_counter( struct draw_stage *stage )
 243 {
 244    /* no-op */
 245 }
 246
 247 static void
 248 select_destroy( struct draw_stage *stage )
 249 {
 250    free(stage);
 251 }
 252
 253
 254 /**
 255  * Create GL selection mode drawing stage.
 256  */
 257 static struct draw_stage *
 258 draw_glselect_stage(struct gl_context *ctx, struct draw_context *draw)
 259 {
 260    struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
 261
 262    fs->stage.draw = draw;
 263    fs->stage.next = NULL;
 264    fs->stage.point = select_point;
 265    fs->stage.line = select_line;
 266    fs->stage.tri = select_tri;
 267    fs->stage.flush = select_flush;
 268    fs->stage.reset_stipple_counter = select_reset_stipple_counter;
 269    fs->stage.destroy = select_destroy;
 270    fs->ctx = ctx;
 271
 272    return &fs->stage;
 273 }
 274
 275
 276 static void
 277 st_RenderMode(struct gl_context *ctx, GLenum newMode )
 278 {
 279    struct st_context *st = st_context(ctx);
 280    struct draw_context *draw = st_get_draw_context(st);
 281
 282    if (!st->draw)
 283       return;
 284
 285    if (newMode == GL_RENDER) {
 286       /* restore normal VBO draw function */
 287       st_init_draw_functions(&ctx->Driver);
 288    }
 289    else if (newMode == GL_SELECT) {
 290       if (!st->selection_stage)
 291          st->selection_stage = draw_glselect_stage(ctx, draw);
 292       draw_set_rasterize_stage(draw, st->selection_stage);
 293       /* Plug in new vbo draw function */
 294       ctx->Driver.Draw = st_feedback_draw_vbo;
 295    }
 296    else {
 297       struct gl_program *vp = st->ctx->VertexProgram._Current;
 298
 299       if (!st->feedback_stage)
 300          st->feedback_stage = draw_glfeedback_stage(ctx, draw);
 301       draw_set_rasterize_stage(draw, st->feedback_stage);
 302       /* Plug in new vbo draw function */
 303       ctx->Driver.Draw = st_feedback_draw_vbo;
 304       /* need to generate/use a vertex program that emits pos/color/tex */
 305       if (vp)
 306          st->dirty |= ST_NEW_VERTEX_PROGRAM(st, st_vertex_program(vp));
 307    }
 308 }
 309
 310
 311
 312 void st_init_feedback_functions(struct dd_function_table *functions)
 313 {
 314    functions->RenderMode = st_RenderMode;
 315 }