src/mesa/state_tracker/st_cb_feedback.c

   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  * 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
  44 #include "vbo/vbo.h"
  45
  46 #include "st_context.h"
  47 #include "st_draw.h"
  48 #include "st_cb_feedback.h"
  49
  50 #include "pipe/p_context.h"
  51 #include "pipe/p_defines.h"
  52
  53 #include "draw/draw_context.h"
  54 #include "draw/draw_pipe.h"
  55
  56
  57 /**
  58  * This is actually used for both feedback and selection.
  59  */
  60 struct feedback_stage
  61 {
  62    struct draw_stage stage;   /**< Base class */
  63    GLcontext *ctx;            /**< Rendering context */
  64    GLboolean reset_stipple_counter;
  65 };
  66
  67
  68 /**********************************************************************
  69  * GL Feedback functions
  70  **********************************************************************/
  71
  72 static INLINE struct feedback_stage *
  73 feedback_stage( struct draw_stage *stage )
  74 {
  75    return (struct feedback_stage *)stage;
  76 }
  77
  78
  79 static void
  80 feedback_vertex(GLcontext *ctx, const struct draw_context *draw,
  81                 const struct vertex_header *v)
  82 {
  83    const struct st_context *st = ctx->st;
  84    GLfloat win[4];
  85    const GLfloat *color, *texcoord;
  86    GLuint slot;
  87
  88    /* Recall that Y=0=Top of window for Gallium wincoords */
  89    win[0] = v->data[0][0];
  90    win[1] = ctx->DrawBuffer->Height - v->data[0][1];
  91    win[2] = v->data[0][2];
  92    win[3] = 1.0F / v->data[0][3];
  93
  94    /* XXX
  95     * When we compute vertex layout, save info about position of the
  96     * color and texcoord attribs to use here.
  97     */
  98
  99    slot = st->vertex_result_to_slot[VERT_RESULT_COL0];
 100    if (slot != ~0U)
 101       color = v->data[slot];
 102    else
 103       color = ctx->Current.Attrib[VERT_ATTRIB_COLOR0];
 104
 105    slot = st->vertex_result_to_slot[VERT_RESULT_TEX0];
 106    if (slot != ~0U)
 107       texcoord = v->data[slot];
 108    else
 109       texcoord = ctx->Current.Attrib[VERT_ATTRIB_TEX0];
 110
 111    _mesa_feedback_vertex(ctx, win, color, texcoord);
 112 }
 113
 114
 115 static void
 116 feedback_tri( struct draw_stage *stage, struct prim_header *prim )
 117 {
 118    struct feedback_stage *fs = feedback_stage(stage);
 119    struct draw_context *draw = stage->draw;
 120    _mesa_feedback_token(fs->ctx, (GLfloat) GL_POLYGON_TOKEN);
 121    _mesa_feedback_token(fs->ctx, (GLfloat) 3); /* three vertices */
 122    feedback_vertex(fs->ctx, draw, prim->v[0]);
 123    feedback_vertex(fs->ctx, draw, prim->v[1]);
 124    feedback_vertex(fs->ctx, draw, prim->v[2]);
 125 }
 126
 127
 128 static void
 129 feedback_line( struct draw_stage *stage, struct prim_header *prim )
 130 {
 131    struct feedback_stage *fs = feedback_stage(stage);
 132    struct draw_context *draw = stage->draw;
 133    if (fs->reset_stipple_counter) {
 134       _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_RESET_TOKEN);
 135       fs->reset_stipple_counter = GL_FALSE;
 136    }
 137    else {
 138       _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_TOKEN);
 139    }
 140    feedback_vertex(fs->ctx, draw, prim->v[0]);
 141    feedback_vertex(fs->ctx, draw, prim->v[1]);
 142 }
 143
 144
 145 static void
 146 feedback_point( struct draw_stage *stage, struct prim_header *prim )
 147 {
 148    struct feedback_stage *fs = feedback_stage(stage);
 149    struct draw_context *draw = stage->draw;
 150    _mesa_feedback_token(fs->ctx, (GLfloat) GL_POINT_TOKEN);
 151    feedback_vertex(fs->ctx, draw, prim->v[0]);
 152 }
 153
 154
 155 static void
 156 feedback_flush( struct draw_stage *stage, unsigned flags )
 157 {
 158    /* no-op */
 159 }
 160
 161
 162 static void
 163 feedback_reset_stipple_counter( struct draw_stage *stage )
 164 {
 165    struct feedback_stage *fs = feedback_stage(stage);
 166    fs->reset_stipple_counter = GL_TRUE;
 167 }
 168
 169
 170 static void
 171 feedback_destroy( struct draw_stage *stage )
 172 {
 173    /* no-op */
 174 }
 175
 176 /**
 177  * Create GL feedback drawing stage.
 178  */
 179 static struct draw_stage *
 180 draw_glfeedback_stage(GLcontext *ctx, struct draw_context *draw)
 181 {
 182    struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
 183
 184    fs->stage.draw = draw;
 185    fs->stage.next = NULL;
 186    fs->stage.point = feedback_point;
 187    fs->stage.line = feedback_line;
 188    fs->stage.tri = feedback_tri;
 189    fs->stage.flush = feedback_flush;
 190    fs->stage.reset_stipple_counter = feedback_reset_stipple_counter;
 191    fs->stage.destroy = feedback_destroy;
 192    fs->ctx = ctx;
 193
 194    return &fs->stage;
 195 }
 196
 197
 198
 199 /**********************************************************************
 200  * GL Selection functions
 201  **********************************************************************/
 202
 203 static void
 204 select_tri( struct draw_stage *stage, struct prim_header *prim )
 205 {
 206    struct feedback_stage *fs = feedback_stage(stage);
 207    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 208    _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
 209    _mesa_update_hitflag( fs->ctx, prim->v[2]->data[0][2] );
 210 }
 211
 212 static void
 213 select_line( struct draw_stage *stage, struct prim_header *prim )
 214 {
 215    struct feedback_stage *fs = feedback_stage(stage);
 216    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 217    _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
 218 }
 219
 220
 221 static void
 222 select_point( struct draw_stage *stage, struct prim_header *prim )
 223 {
 224    struct feedback_stage *fs = feedback_stage(stage);
 225    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 226 }
 227
 228
 229 static void
 230 select_flush( struct draw_stage *stage, unsigned flags )
 231 {
 232    /* no-op */
 233 }
 234
 235
 236 static void
 237 select_reset_stipple_counter( struct draw_stage *stage )
 238 {
 239    /* no-op */
 240 }
 241
 242 static void
 243 select_destroy( struct draw_stage *stage )
 244 {
 245    /* no-op */
 246 }
 247
 248
 249 /**
 250  * Create GL selection mode drawing stage.
 251  */
 252 static struct draw_stage *
 253 draw_glselect_stage(GLcontext *ctx, struct draw_context *draw)
 254 {
 255    struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
 256
 257    fs->stage.draw = draw;
 258    fs->stage.next = NULL;
 259    fs->stage.point = select_point;
 260    fs->stage.line = select_line;
 261    fs->stage.tri = select_tri;
 262    fs->stage.flush = select_flush;
 263    fs->stage.reset_stipple_counter = select_reset_stipple_counter;
 264    fs->stage.destroy = select_destroy;
 265    fs->ctx = ctx;
 266
 267    return &fs->stage;
 268 }
 269
 270
 271 static void
 272 st_RenderMode(GLcontext *ctx, GLenum newMode )
 273 {
 274    struct st_context *st = ctx->st;
 275    struct draw_context *draw = st->draw;
 276
 277    if (newMode == GL_RENDER) {
 278       /* restore normal VBO draw function */
 279       vbo_set_draw_func(ctx, st_draw_vbo);
 280    }
 281    else if (newMode == GL_SELECT) {
 282       if (!st->selection_stage)
 283          st->selection_stage = draw_glselect_stage(ctx, draw);
 284       draw_set_rasterize_stage(draw, st->selection_stage);
 285       /* Plug in new vbo draw function */
 286       vbo_set_draw_func(ctx, st_feedback_draw_vbo);
 287    }
 288    else {
 289       if (!st->feedback_stage)
 290          st->feedback_stage = draw_glfeedback_stage(ctx, draw);
 291       draw_set_rasterize_stage(draw, st->feedback_stage);
 292       /* Plug in new vbo draw function */
 293       vbo_set_draw_func(ctx, st_feedback_draw_vbo);
 294       /* need to generate/use a vertex program that emits pos/color/tex */
 295       st->dirty.st |= ST_NEW_VERTEX_PROGRAM;
 296    }
 297 }
 298
 299
 300
 301 void st_init_feedback_functions(struct dd_function_table *functions)
 302 {
 303    functions->RenderMode = st_RenderMode;
 304 }