src/mesa/main/state.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2008  Brian Paul   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 "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /**
  27  * \file state.c
  28  * State management.
  29  *
  30  * This file manages recalculation of derived values in struct gl_context.
  31  */
  32
  33
  34 #include "glheader.h"
  35 #include "mtypes.h"
  36 #include "arrayobj.h"
  37 #include "context.h"
  38 #include "debug.h"
  39 #include "macros.h"
  40 #include "ffvertex_prog.h"
  41 #include "framebuffer.h"
  42 #include "light.h"
  43 #include "matrix.h"
  44 #include "pixel.h"
  45 #include "program/program.h"
  46 #include "program/prog_parameter.h"
  47 #include "shaderobj.h"
  48 #include "state.h"
  49 #include "stencil.h"
  50 #include "texenvprogram.h"
  51 #include "texobj.h"
  52 #include "texstate.h"
  53 #include "varray.h"
  54 #include "viewport.h"
  55 #include "blend.h"
  56
  57
  58 /**
  59  * Update the following fields:
  60  *   ctx->VertexProgram._Enabled
  61  *   ctx->FragmentProgram._Enabled
  62  *   ctx->ATIFragmentShader._Enabled
  63  * This needs to be done before texture state validation.
  64  */
  65 static void
  66 update_program_enables(struct gl_context *ctx)
  67 {
  68    /* These _Enabled flags indicate if the user-defined ARB/NV vertex/fragment
  69     * program is enabled AND valid.  Similarly for ATI fragment shaders.
  70     * GLSL shaders not relevant here.
  71     */
  72    ctx->VertexProgram._Enabled = ctx->VertexProgram.Enabled
  73       && ctx->VertexProgram.Current->arb.Instructions;
  74    ctx->FragmentProgram._Enabled = ctx->FragmentProgram.Enabled
  75       && ctx->FragmentProgram.Current->arb.Instructions;
  76    ctx->ATIFragmentShader._Enabled = ctx->ATIFragmentShader.Enabled
  77       && ctx->ATIFragmentShader.Current->Instructions[0];
  78 }
  79
  80
  81 /**
  82  * Update the ctx->*Program._Current pointers to point to the
  83  * current/active programs.
  84  *
  85  * Programs may come from 3 sources: GLSL shaders, ARB/NV_vertex/fragment
  86  * programs or programs derived from fixed-function state.
  87  *
  88  * This function needs to be called after texture state validation in case
  89  * we're generating a fragment program from fixed-function texture state.
  90  *
  91  * \return bitfield which will indicate _NEW_PROGRAM state if a new vertex
  92  * or fragment program is being used.
  93  */
  94 static GLbitfield
  95 update_program(struct gl_context *ctx)
  96 {
  97    struct gl_program *vsProg =
  98       ctx->_Shader->CurrentProgram[MESA_SHADER_VERTEX];
  99    struct gl_program *tcsProg =
 100       ctx->_Shader->CurrentProgram[MESA_SHADER_TESS_CTRL];
 101    struct gl_program *tesProg =
 102       ctx->_Shader->CurrentProgram[MESA_SHADER_TESS_EVAL];
 103    struct gl_program *gsProg =
 104       ctx->_Shader->CurrentProgram[MESA_SHADER_GEOMETRY];
 105    struct gl_program *fsProg =
 106       ctx->_Shader->CurrentProgram[MESA_SHADER_FRAGMENT];
 107    struct gl_program *csProg =
 108       ctx->_Shader->CurrentProgram[MESA_SHADER_COMPUTE];
 109    const struct gl_program *prevVP = ctx->VertexProgram._Current;
 110    const struct gl_program *prevFP = ctx->FragmentProgram._Current;
 111    const struct gl_program *prevGP = ctx->GeometryProgram._Current;
 112    const struct gl_program *prevTCP = ctx->TessCtrlProgram._Current;
 113    const struct gl_program *prevTEP = ctx->TessEvalProgram._Current;
 114    const struct gl_program *prevCP = ctx->ComputeProgram._Current;
 115    GLbitfield new_state = 0x0;
 116
 117    /*
 118     * Set the ctx->VertexProgram._Current and ctx->FragmentProgram._Current
 119     * pointers to the programs that should be used for rendering.  If either
 120     * is NULL, use fixed-function code paths.
 121     *
 122     * These programs may come from several sources.  The priority is as
 123     * follows:
 124     *   1. OpenGL 2.0/ARB vertex/fragment shaders
 125     *   2. ARB/NV vertex/fragment programs
 126     *   3. ATI fragment shader
 127     *   4. Programs derived from fixed-function state.
 128     *
 129     * Note: it's possible for a vertex shader to get used with a fragment
 130     * program (and vice versa) here, but in practice that shouldn't ever
 131     * come up, or matter.
 132     */
 133
 134    if (fsProg) {
 135       /* Use GLSL fragment shader */
 136       _mesa_reference_program(ctx, &ctx->FragmentProgram._Current, fsProg);
 137       _mesa_reference_program(ctx, &ctx->FragmentProgram._TexEnvProgram,
 138                               NULL);
 139    }
 140    else if (ctx->FragmentProgram._Enabled) {
 141       /* Use user-defined fragment program */
 142       _mesa_reference_program(ctx, &ctx->FragmentProgram._Current,
 143                               ctx->FragmentProgram.Current);
 144       _mesa_reference_program(ctx, &ctx->FragmentProgram._TexEnvProgram,
 145                               NULL);
 146    }
 147    else if (ctx->ATIFragmentShader._Enabled &&
 148             ctx->ATIFragmentShader.Current->Program) {
 149        /* Use the enabled ATI fragment shader's associated program */
 150       _mesa_reference_program(ctx, &ctx->FragmentProgram._Current,
 151                               ctx->ATIFragmentShader.Current->Program);
 152       _mesa_reference_program(ctx, &ctx->FragmentProgram._TexEnvProgram,
 153                               NULL);
 154    }
 155    else if (ctx->FragmentProgram._MaintainTexEnvProgram) {
 156       /* Use fragment program generated from fixed-function state */
 157       struct gl_shader_program *f = _mesa_get_fixed_func_fragment_program(ctx);
 158
 159       _mesa_reference_program(ctx, &ctx->FragmentProgram._Current,
 160                               f->_LinkedShaders[MESA_SHADER_FRAGMENT]->Program);
 161       _mesa_reference_program(ctx, &ctx->FragmentProgram._TexEnvProgram,
 162                               f->_LinkedShaders[MESA_SHADER_FRAGMENT]->Program);
 163    }
 164    else {
 165       /* No fragment program */
 166       _mesa_reference_program(ctx, &ctx->FragmentProgram._Current, NULL);
 167       _mesa_reference_program(ctx, &ctx->FragmentProgram._TexEnvProgram,
 168                               NULL);
 169    }
 170
 171    if (gsProg) {
 172       /* Use GLSL geometry shader */
 173       _mesa_reference_program(ctx, &ctx->GeometryProgram._Current, gsProg);
 174    } else {
 175       /* No geometry program */
 176       _mesa_reference_program(ctx, &ctx->GeometryProgram._Current, NULL);
 177    }
 178
 179    if (tesProg) {
 180       /* Use GLSL tessellation evaluation shader */
 181       _mesa_reference_program(ctx, &ctx->TessEvalProgram._Current, tesProg);
 182    }
 183    else {
 184       /* No tessellation evaluation program */
 185       _mesa_reference_program(ctx, &ctx->TessEvalProgram._Current, NULL);
 186    }
 187
 188    if (tcsProg) {
 189       /* Use GLSL tessellation control shader */
 190       _mesa_reference_program(ctx, &ctx->TessCtrlProgram._Current, tcsProg);
 191    }
 192    else {
 193       /* No tessellation control program */
 194       _mesa_reference_program(ctx, &ctx->TessCtrlProgram._Current, NULL);
 195    }
 196
 197    /* Examine vertex program after fragment program as
 198     * _mesa_get_fixed_func_vertex_program() needs to know active
 199     * fragprog inputs.
 200     */
 201    if (vsProg) {
 202       /* Use GLSL vertex shader */
 203       _mesa_reference_program(ctx, &ctx->VertexProgram._Current, vsProg);
 204    }
 205    else if (ctx->VertexProgram._Enabled) {
 206       /* Use user-defined vertex program */
 207       _mesa_reference_program(ctx, &ctx->VertexProgram._Current,
 208                               ctx->VertexProgram.Current);
 209    }
 210    else if (ctx->VertexProgram._MaintainTnlProgram) {
 211       /* Use vertex program generated from fixed-function state */
 212       _mesa_reference_program(ctx, &ctx->VertexProgram._Current,
 213                               _mesa_get_fixed_func_vertex_program(ctx));
 214       _mesa_reference_program(ctx, &ctx->VertexProgram._TnlProgram,
 215                               ctx->VertexProgram._Current);
 216    }
 217    else {
 218       /* no vertex program */
 219       _mesa_reference_program(ctx, &ctx->VertexProgram._Current, NULL);
 220    }
 221
 222    if (csProg) {
 223       /* Use GLSL compute shader */
 224       _mesa_reference_program(ctx, &ctx->ComputeProgram._Current, csProg);
 225    } else {
 226       /* no compute program */
 227       _mesa_reference_program(ctx, &ctx->ComputeProgram._Current, NULL);
 228    }
 229
 230    /* Let the driver know what's happening:
 231     */
 232    if (ctx->FragmentProgram._Current != prevFP ||
 233        ctx->VertexProgram._Current != prevVP ||
 234        ctx->GeometryProgram._Current != prevGP ||
 235        ctx->TessEvalProgram._Current != prevTEP ||
 236        ctx->TessCtrlProgram._Current != prevTCP ||
 237        ctx->ComputeProgram._Current != prevCP)
 238       new_state |= _NEW_PROGRAM;
 239
 240    return new_state;
 241 }
 242
 243
 244 /**
 245  * Examine shader constants and return either _NEW_PROGRAM_CONSTANTS or 0.
 246  */
 247 static GLbitfield
 248 update_program_constants(struct gl_context *ctx)
 249 {
 250    GLbitfield new_state = 0x0;
 251
 252    if (ctx->FragmentProgram._Current) {
 253       const struct gl_program_parameter_list *params =
 254          ctx->FragmentProgram._Current->Parameters;
 255       if (params && params->StateFlags & ctx->NewState) {
 256          new_state |= _NEW_PROGRAM_CONSTANTS;
 257       }
 258    }
 259
 260    /* Don't handle tessellation and geometry shaders here. They don't use
 261     * any state constants.
 262     */
 263
 264    if (ctx->VertexProgram._Current) {
 265       const struct gl_program_parameter_list *params =
 266          ctx->VertexProgram._Current->Parameters;
 267       if (params && params->StateFlags & ctx->NewState) {
 268          new_state |= _NEW_PROGRAM_CONSTANTS;
 269       }
 270    }
 271
 272    return new_state;
 273 }
 274
 275
 276
 277
 278 /**
 279  * Update the ctx->Polygon._FrontBit flag.
 280  */
 281 static void
 282 update_frontbit(struct gl_context *ctx)
 283 {
 284    if (ctx->Transform.ClipOrigin == GL_LOWER_LEFT)
 285       ctx->Polygon._FrontBit = (ctx->Polygon.FrontFace == GL_CW);
 286    else
 287       ctx->Polygon._FrontBit = (ctx->Polygon.FrontFace == GL_CCW);
 288 }
 289
 290
 291 /**
 292  * Update the ctx->VertexProgram._TwoSideEnabled flag.
 293  */
 294 static void
 295 update_twoside(struct gl_context *ctx)
 296 {
 297    if (ctx->_Shader->CurrentProgram[MESA_SHADER_VERTEX] ||
 298        ctx->VertexProgram._Enabled) {
 299       ctx->VertexProgram._TwoSideEnabled = ctx->VertexProgram.TwoSideEnabled;
 300    } else {
 301       ctx->VertexProgram._TwoSideEnabled = (ctx->Light.Enabled &&
 302                                             ctx->Light.Model.TwoSide);
 303    }
 304 }
 305
 306
 307 /**
 308  * Compute derived GL state.
 309  * If __struct gl_contextRec::NewState is non-zero then this function \b must
 310  * be called before rendering anything.
 311  *
 312  * Calls dd_function_table::UpdateState to perform any internal state
 313  * management necessary.
 314  *
 315  * \sa _mesa_update_modelview_project(), _mesa_update_texture(),
 316  * _mesa_update_buffer_bounds(),
 317  * _mesa_update_lighting() and _mesa_update_tnl_spaces().
 318  */
 319 void
 320 _mesa_update_state_locked( struct gl_context *ctx )
 321 {
 322    GLbitfield new_state = ctx->NewState;
 323    GLbitfield prog_flags = _NEW_PROGRAM;
 324    GLbitfield new_prog_state = 0x0;
 325    const GLbitfield computed_states = ~(_NEW_CURRENT_ATTRIB | _NEW_LINE);
 326
 327    /* we can skip a bunch of state validation checks if the dirty
 328     * state matches one or more bits in 'computed_states'.
 329     */
 330    if ((new_state & computed_states) == 0)
 331       goto out;
 332
 333    if (MESA_VERBOSE & VERBOSE_STATE)
 334       _mesa_print_state("_mesa_update_state", new_state);
 335
 336    /* Determine which state flags effect vertex/fragment program state */
 337    if (ctx->FragmentProgram._MaintainTexEnvProgram) {
 338       prog_flags |= (_NEW_BUFFERS | _NEW_TEXTURE_OBJECT | _NEW_FOG |
 339                      _NEW_VARYING_VP_INPUTS | _NEW_LIGHT | _NEW_POINT |
 340                      _NEW_RENDERMODE | _NEW_PROGRAM | _NEW_FRAG_CLAMP |
 341                      _NEW_COLOR | _NEW_TEXTURE_STATE);
 342    }
 343    if (ctx->VertexProgram._MaintainTnlProgram) {
 344       prog_flags |= (_NEW_VARYING_VP_INPUTS | _NEW_TEXTURE_OBJECT |
 345                      _NEW_TEXTURE_MATRIX | _NEW_TRANSFORM | _NEW_POINT |
 346                      _NEW_FOG | _NEW_LIGHT | _NEW_TEXTURE_STATE |
 347                      _MESA_NEW_NEED_EYE_COORDS);
 348    }
 349
 350    /*
 351     * Now update derived state info
 352     */
 353
 354    if (new_state & prog_flags)
 355       update_program_enables( ctx );
 356
 357    if (new_state & (_NEW_MODELVIEW|_NEW_PROJECTION))
 358       _mesa_update_modelview_project( ctx, new_state );
 359
 360    if (new_state & _NEW_TEXTURE_MATRIX)
 361       _mesa_update_texture_matrices(ctx);
 362
 363    if (new_state & (_NEW_TEXTURE_OBJECT | _NEW_TEXTURE_STATE | _NEW_PROGRAM))
 364       _mesa_update_texture_state(ctx);
 365
 366    if (new_state & _NEW_POLYGON)
 367       update_frontbit( ctx );
 368
 369    if (new_state & _NEW_BUFFERS)
 370       _mesa_update_framebuffer(ctx, ctx->ReadBuffer, ctx->DrawBuffer);
 371
 372    if (new_state & (_NEW_SCISSOR | _NEW_BUFFERS | _NEW_VIEWPORT))
 373       _mesa_update_draw_buffer_bounds(ctx, ctx->DrawBuffer);
 374
 375    if (new_state & _NEW_LIGHT)
 376       _mesa_update_lighting( ctx );
 377
 378    if (new_state & (_NEW_LIGHT | _NEW_PROGRAM))
 379       update_twoside( ctx );
 380
 381    if (new_state & (_NEW_STENCIL | _NEW_BUFFERS))
 382       _mesa_update_stencil( ctx );
 383
 384    if (new_state & _NEW_PIXEL)
 385       _mesa_update_pixel( ctx );
 386
 387    /* ctx->_NeedEyeCoords is now up to date.
 388     *
 389     * If the truth value of this variable has changed, update for the
 390     * new lighting space and recompute the positions of lights and the
 391     * normal transform.
 392     *
 393     * If the lighting space hasn't changed, may still need to recompute
 394     * light positions & normal transforms for other reasons.
 395     */
 396    if (new_state & _MESA_NEW_NEED_EYE_COORDS)
 397       _mesa_update_tnl_spaces( ctx, new_state );
 398
 399    if (new_state & prog_flags) {
 400       /* When we generate programs from fixed-function vertex/fragment state
 401        * this call may generate/bind a new program.  If so, we need to
 402        * propogate the _NEW_PROGRAM flag to the driver.
 403        */
 404       new_prog_state |= update_program( ctx );
 405    }
 406
 407    if (new_state & _NEW_ARRAY)
 408       _mesa_update_vao_client_arrays(ctx, ctx->Array.VAO);
 409
 410  out:
 411    new_prog_state |= update_program_constants(ctx);
 412
 413    /*
 414     * Give the driver a chance to act upon the new_state flags.
 415     * The driver might plug in different span functions, for example.
 416     * Also, this is where the driver can invalidate the state of any
 417     * active modules (such as swrast_setup, swrast, tnl, etc).
 418     *
 419     * Set ctx->NewState to zero to avoid recursion if
 420     * Driver.UpdateState() has to call FLUSH_VERTICES().  (fixed?)
 421     */
 422    new_state = ctx->NewState | new_prog_state;
 423    ctx->NewState = 0;
 424    ctx->Driver.UpdateState(ctx, new_state);
 425    ctx->Array.VAO->NewArrays = 0x0;
 426 }
 427
 428
 429 /* This is the usual entrypoint for state updates:
 430  */
 431 void
 432 _mesa_update_state( struct gl_context *ctx )
 433 {
 434    _mesa_lock_context_textures(ctx);
 435    _mesa_update_state_locked(ctx);
 436    _mesa_unlock_context_textures(ctx);
 437 }
 438
 439
 440
 441
 442 /**
 443  * Want to figure out which fragment program inputs are actually
 444  * constant/current values from ctx->Current.  These should be
 445  * referenced as a tracked state variable rather than a fragment
 446  * program input, to save the overhead of putting a constant value in
 447  * every submitted vertex, transferring it to hardware, interpolating
 448  * it across the triangle, etc...
 449  *
 450  * When there is a VP bound, just use vp->outputs.  But when we're
 451  * generating vp from fixed function state, basically want to
 452  * calculate:
 453  *
 454  * vp_out_2_fp_in( vp_in_2_vp_out( varying_inputs ) |
 455  *                 potential_vp_outputs )
 456  *
 457  * Where potential_vp_outputs is calculated by looking at enabled
 458  * texgen, etc.
 459  *
 460  * The generated fragment program should then only declare inputs that
 461  * may vary or otherwise differ from the ctx->Current values.
 462  * Otherwise, the fp should track them as state values instead.
 463  */
 464 void
 465 _mesa_set_varying_vp_inputs( struct gl_context *ctx,
 466                              GLbitfield64 varying_inputs )
 467 {
 468    if (ctx->varying_vp_inputs != varying_inputs) {
 469       ctx->varying_vp_inputs = varying_inputs;
 470
 471       /* Only the fixed-func generated programs need to use the flag
 472        * and the fixed-func fragment program uses it only if there is also
 473        * a fixed-func vertex program, so this only depends on the latter.
 474        *
 475        * It's okay to check the VP pointer here, because this is called after
 476        * _mesa_update_state in the vbo module. */
 477       if (ctx->VertexProgram._TnlProgram ||
 478           ctx->FragmentProgram._TexEnvProgram) {
 479          ctx->NewState |= _NEW_VARYING_VP_INPUTS;
 480       }
 481       /*printf("%s %x\n", __func__, varying_inputs);*/
 482    }
 483 }
 484
 485
 486 /**
 487  * Used by drivers to tell core Mesa that the driver is going to
 488  * install/ use its own vertex program.  In particular, this will
 489  * prevent generated fragment programs from using state vars instead
 490  * of ordinary varyings/inputs.
 491  */
 492 void
 493 _mesa_set_vp_override(struct gl_context *ctx, GLboolean flag)
 494 {
 495    if (ctx->VertexProgram._Overriden != flag) {
 496       ctx->VertexProgram._Overriden = flag;
 497
 498       /* Set one of the bits which will trigger fragment program
 499        * regeneration:
 500        */
 501       ctx->NewState |= _NEW_PROGRAM;
 502    }
 503 }