src/mesa/vbo/vbo_exec.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.3
   4  *
   5  * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  *
  25  * Authors:
  26  *    Keith Whitwell <keith@tungstengraphics.com>
  27  */
  28
  29
  30 #include "main/api_arrayelt.h"
  31 #include "main/glheader.h"
  32 #include "main/mtypes.h"
  33 #include "main/vtxfmt.h"
  34 #include "vbo_context.h"
  35
  36
  37
  38 void vbo_exec_init( struct gl_context *ctx )
  39 {
  40    struct vbo_exec_context *exec = &vbo_context(ctx)->exec;
  41
  42    exec->ctx = ctx;
  43
  44    /* Initialize the arrayelt helper
  45     */
  46    if (!ctx->aelt_context &&
  47        !_ae_create_context( ctx ))
  48       return;
  49
  50    vbo_exec_vtx_init( exec );
  51    vbo_exec_array_init( exec );
  52
  53    ctx->Driver.NeedFlush = 0;
  54    ctx->Driver.CurrentExecPrimitive = PRIM_OUTSIDE_BEGIN_END;
  55    ctx->Driver.BeginVertices = vbo_exec_BeginVertices;
  56    ctx->Driver.FlushVertices = vbo_exec_FlushVertices;
  57
  58    vbo_exec_invalidate_state( ctx, ~0 );
  59 }
  60
  61
  62 void vbo_exec_destroy( struct gl_context *ctx )
  63 {
  64    struct vbo_exec_context *exec = &vbo_context(ctx)->exec;
  65
  66    if (ctx->aelt_context) {
  67       _ae_destroy_context( ctx );
  68       ctx->aelt_context = NULL;
  69    }
  70
  71    vbo_exec_vtx_destroy( exec );
  72    vbo_exec_array_destroy( exec );
  73 }
  74
  75
  76 /**
  77  * Really want to install these callbacks to a central facility to be
  78  * invoked according to the state flags.  That will have to wait for a
  79  * mesa rework:
  80  */
  81 void vbo_exec_invalidate_state( struct gl_context *ctx, GLuint new_state )
  82 {
  83    struct vbo_context *vbo = vbo_context(ctx);
  84    struct vbo_exec_context *exec = &vbo->exec;
  85
  86    if (!exec->validating && new_state & (_NEW_PROGRAM|_NEW_ARRAY)) {
  87       exec->array.recalculate_inputs = GL_TRUE;
  88
  89       /* If we ended up here because a VAO was deleted, the _DrawArrays
  90        * pointer which pointed to the VAO might be invalid now, so set it
  91        * to NULL.  This prevents crashes in driver functions like Clear
  92        * where driver state validation might occur, but the vbo module is
  93        * still in an invalid state.
  94        *
  95        * Drivers should skip vertex array state validation if _DrawArrays
  96        * is NULL.  It also has no effect on performance, because attrib
  97        * bindings will be recalculated anyway.
  98        */
  99       if (vbo->last_draw_method == DRAW_ARRAYS) {
 100          ctx->Array._DrawArrays = NULL;
 101          vbo->last_draw_method = DRAW_NONE;
 102       }
 103    }
 104
 105    if (new_state & _NEW_EVAL)
 106       exec->eval.recalculate_maps = 1;
 107
 108    _ae_invalidate_state(ctx, new_state);
 109 }
 110
 111
 112 /**
 113  * Figure out the number of transform feedback primitives that will be output
 114  * considering the drawing mode, number of vertices, and instance count,
 115  * assuming that no geometry shading is done and primitive restart is not
 116  * used.
 117  *
 118  * This is used by driver back-ends in implementing the PRIMITIVES_GENERATED
 119  * and TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN queries.  It is also used to
 120  * pre-validate draw calls in GLES3 (where draw calls only succeed if there is
 121  * enough room in the transform feedback buffer for the result).
 122  */
 123 size_t
 124 vbo_count_tessellated_primitives(GLenum mode, GLuint count,
 125                                  GLuint num_instances)
 126 {
 127    size_t num_primitives;
 128    switch (mode) {
 129    case GL_POINTS:
 130       num_primitives = count;
 131       break;
 132    case GL_LINE_STRIP:
 133       num_primitives = count >= 2 ? count - 1 : 0;
 134       break;
 135    case GL_LINE_LOOP:
 136       num_primitives = count >= 2 ? count : 0;
 137       break;
 138    case GL_LINES:
 139       num_primitives = count / 2;
 140       break;
 141    case GL_TRIANGLE_STRIP:
 142    case GL_TRIANGLE_FAN:
 143    case GL_POLYGON:
 144       num_primitives = count >= 3 ? count - 2 : 0;
 145       break;
 146    case GL_TRIANGLES:
 147       num_primitives = count / 3;
 148       break;
 149    case GL_QUAD_STRIP:
 150       num_primitives = count >= 4 ? ((count / 2) - 1) * 2 : 0;
 151       break;
 152    case GL_QUADS:
 153       num_primitives = (count / 4) * 2;
 154       break;
 155    default:
 156       assert(!"Unexpected primitive type in count_tessellated_primitives");
 157       num_primitives = 0;
 158       break;
 159    }
 160    return num_primitives * num_instances;
 161 }