src/mesa/state_tracker/st_cb_rasterpos.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  * 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
  43 #include "st_context.h"
  44 #include "st_atom.h"
  45 #include "st_draw.h"
  46 #include "st_cb_rasterpos.h"
  47 #include "st_draw.h"
  48 #include "draw/draw_context.h"
  49 #include "draw/draw_pipe.h"
  50 #include "shader/prog_instruction.h"
  51 #include "vbo/vbo.h"
  52
  53
  54
  55 /**
  56  * Our special drawing pipeline stage (replaces rasterization).
  57  */
  58 struct rastpos_stage
  59 {
  60    struct draw_stage stage;   /**< Base class */
  61    GLcontext *ctx;            /**< Rendering context */
  62
  63    /* vertex attrib info we can setup once and re-use */
  64    struct gl_client_array array[VERT_ATTRIB_MAX];
  65    const struct gl_client_array *arrays[VERT_ATTRIB_MAX];
  66    struct _mesa_prim prim;
  67 };
  68
  69
  70 static INLINE struct rastpos_stage *
  71 rastpos_stage( struct draw_stage *stage )
  72 {
  73    return (struct rastpos_stage *) stage;
  74 }
  75
  76 static void
  77 rastpos_flush( struct draw_stage *stage, unsigned flags )
  78 {
  79    /* no-op */
  80 }
  81
  82 static void
  83 rastpos_reset_stipple_counter( struct draw_stage *stage )
  84 {
  85    /* no-op */
  86 }
  87
  88 static void
  89 rastpos_tri( struct draw_stage *stage, struct prim_header *prim )
  90 {
  91    /* should never get here */
  92    assert(0);
  93 }
  94
  95 static void
  96 rastpos_line( struct draw_stage *stage, struct prim_header *prim )
  97 {
  98    /* should never get here */
  99    assert(0);
 100 }
 101
 102 static void
 103 rastpos_destroy(struct draw_stage *stage)
 104 {
 105    free(stage);
 106 }
 107
 108
 109 /**
 110  * Update a raster pos attribute from the vertex result if it's present,
 111  * else copy the current attrib.
 112  */
 113 static void
 114 update_attrib(GLcontext *ctx, const GLuint *outputMapping,
 115               const struct vertex_header *vert,
 116               GLfloat *dest,
 117               GLuint result, GLuint defaultAttrib)
 118 {
 119    const GLfloat *src;
 120    const GLuint k = outputMapping[result];
 121    if (k != ~0U)
 122       src = vert->data[k];
 123    else
 124       src = ctx->Current.Attrib[defaultAttrib];
 125    COPY_4V(dest, src);
 126 }
 127
 128
 129 /**
 130  * Normally, this function would render a GL_POINT.
 131  */
 132 static void
 133 rastpos_point(struct draw_stage *stage, struct prim_header *prim)
 134 {
 135    struct rastpos_stage *rs = rastpos_stage(stage);
 136    GLcontext *ctx = rs->ctx;
 137    struct st_context *st = ctx->st;
 138    const GLfloat height = (GLfloat) ctx->DrawBuffer->Height;
 139    const GLuint *outputMapping = st->vertex_result_to_slot;
 140    const GLfloat *pos;
 141    GLuint i;
 142
 143    /* if we get here, we didn't get clipped */
 144    ctx->Current.RasterPosValid = GL_TRUE;
 145
 146    /* update raster pos */
 147    pos = prim->v[0]->data[0];
 148    ctx->Current.RasterPos[0] = pos[0];
 149    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
 150       ctx->Current.RasterPos[1] = height - pos[1]; /* invert Y */
 151    else
 152       ctx->Current.RasterPos[1] = pos[1];
 153    ctx->Current.RasterPos[2] = pos[2];
 154    ctx->Current.RasterPos[3] = pos[3];
 155
 156    /* update other raster attribs */
 157    update_attrib(ctx, outputMapping, prim->v[0],
 158                  ctx->Current.RasterColor,
 159                  VERT_RESULT_COL0, VERT_ATTRIB_COLOR0);
 160
 161    update_attrib(ctx, outputMapping, prim->v[0],
 162                  ctx->Current.RasterSecondaryColor,
 163                  VERT_RESULT_COL1, VERT_ATTRIB_COLOR1);
 164
 165    for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
 166       update_attrib(ctx, outputMapping, prim->v[0],
 167                     ctx->Current.RasterTexCoords[i],
 168                     VERT_RESULT_TEX0 + i, VERT_ATTRIB_TEX0 + i);
 169    }
 170
 171    if (ctx->RenderMode == GL_SELECT) {
 172       _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
 173    }
 174 }
 175
 176
 177 /**
 178  * Create rasterpos "drawing" stage.
 179  */
 180 static struct rastpos_stage *
 181 new_draw_rastpos_stage(GLcontext *ctx, struct draw_context *draw)
 182 {
 183    struct rastpos_stage *rs = CALLOC_STRUCT(rastpos_stage);
 184    GLuint i;
 185
 186    rs->stage.draw = draw;
 187    rs->stage.next = NULL;
 188    rs->stage.point = rastpos_point;
 189    rs->stage.line = rastpos_line;
 190    rs->stage.tri = rastpos_tri;
 191    rs->stage.flush = rastpos_flush;
 192    rs->stage.destroy = rastpos_destroy;
 193    rs->stage.reset_stipple_counter = rastpos_reset_stipple_counter;
 194    rs->stage.destroy = rastpos_destroy;
 195    rs->ctx = ctx;
 196
 197    for (i = 0; i < VERT_ATTRIB_MAX; i++) {
 198       rs->array[i].Size = 4;
 199       rs->array[i].Type = GL_FLOAT;
 200       rs->array[i].Stride = 0;
 201       rs->array[i].StrideB = 0;
 202       rs->array[i].Ptr = (GLubyte *) ctx->Current.Attrib[i];
 203       rs->array[i].Enabled = GL_TRUE;
 204       rs->array[i].Normalized = GL_TRUE;
 205       rs->array[i].BufferObj = NULL;
 206       rs->arrays[i] = &rs->array[i];
 207    }
 208
 209    rs->prim.mode = GL_POINTS;
 210    rs->prim.indexed = 0;
 211    rs->prim.begin = 1;
 212    rs->prim.end = 1;
 213    rs->prim.weak = 0;
 214    rs->prim.start = 0;
 215    rs->prim.count = 1;
 216
 217    return rs;
 218 }
 219
 220
 221 static void
 222 st_RasterPos(GLcontext *ctx, const GLfloat v[4])
 223 {
 224    struct st_context *st = ctx->st;
 225    struct draw_context *draw = st->draw;
 226    struct rastpos_stage *rs;
 227
 228    if (st->rastpos_stage) {
 229       /* get rastpos stage info */
 230       rs = rastpos_stage(st->rastpos_stage);
 231    }
 232    else {
 233       /* create rastpos draw stage */
 234       rs = new_draw_rastpos_stage(ctx, draw);
 235       st->rastpos_stage = &rs->stage;
 236    }
 237
 238    /* plug our rastpos stage into the draw module */
 239    draw_set_rasterize_stage(st->draw, st->rastpos_stage);
 240
 241    /* make sure everything's up to date */
 242    st_validate_state(ctx->st);
 243
 244    /* This will get set only if rastpos_point(), above, gets called */
 245    ctx->Current.RasterPosValid = GL_FALSE;
 246
 247    /* All vertex attribs but position were previously initialized above.
 248     * Just plug in position pointer now.
 249     */
 250    rs->array[0].Ptr = (GLubyte *) v;
 251
 252    /* draw the point */
 253    st_feedback_draw_vbo(ctx, rs->arrays, &rs->prim, 1, NULL, 0, 1);
 254 }
 255
 256
 257
 258 void st_init_rasterpos_functions(struct dd_function_table *functions)
 259 {
 260    functions->RasterPos = st_RasterPos;
 261 }