state.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

    *   1. OpenGL 2.0/ARB vertex/fragment shaders
    *   2. ARB/NV vertex/fragment programs
    *   3. Programs derived from fixed-function state.
    */

   _mesa_reference_fragprog(ctx, &ctx->FragmentProgram._Current, NULL);

   if (shProg && shProg->LinkStatus) {
      /* Use shader programs */
      /* XXX this isn't quite right, since we may have either a vertex
       * _or_ fragment shader (not always both).
       */
      _mesa_reference_vertprog(ctx, &ctx->VertexProgram._Current,
                               shProg->VertexProgram);
      _mesa_reference_fragprog(ctx, &ctx->FragmentProgram._Current,
                               shProg->FragmentProgram);
   }
   else {
      if (ctx->VertexProgram._Enabled) {
         /* use user-defined vertex program */
         _mesa_reference_vertprog(ctx, &ctx->VertexProgram._Current,
                                  ctx->VertexProgram.Current);
      }
      else if (ctx->VertexProgram._MaintainTnlProgram) {
         /* Use vertex program generated from fixed-function state.
          * The _Current pointer will get set in
          * _tnl_UpdateFixedFunctionProgram() later if appropriate.
          */
         _mesa_reference_vertprog(ctx, &ctx->VertexProgram._Current, NULL);
      }
      else {
         /* no vertex program */
         _mesa_reference_vertprog(ctx, &ctx->VertexProgram._Current, NULL);
      }

      if (ctx->FragmentProgram._Enabled) {
         /* use user-defined vertex program */
         _mesa_reference_fragprog(ctx, &ctx->FragmentProgram._Current,
                                  ctx->FragmentProgram.Current);
      }
      else if (ctx->FragmentProgram._MaintainTexEnvProgram) {
         /* Use fragment program generated from fixed-function state.
          * The _Current pointer will get set in _mesa_UpdateTexEnvProgram()
          * later if appropriate.
          */
         _mesa_reference_fragprog(ctx, &ctx->FragmentProgram._Current, NULL);
      }
      else {
         /* no fragment program */
         _mesa_reference_fragprog(ctx, &ctx->FragmentProgram._Current, NULL);
      }
   }

   if (ctx->VertexProgram._Current)
      assert(ctx->VertexProgram._Current->Base.Parameters);
   if (ctx->FragmentProgram._Current)
      assert(ctx->FragmentProgram._Current->Base.Parameters);


   ctx->FragmentProgram._Active = ctx->FragmentProgram._Enabled;
   if (ctx->FragmentProgram._MaintainTexEnvProgram &&
       !ctx->FragmentProgram._Enabled) {
      if (ctx->FragmentProgram._UseTexEnvProgram)
	 ctx->FragmentProgram._Active = GL_TRUE;
   }
}


static void
update_viewport_matrix(GLcontext *ctx)
{
   const GLfloat depthMax = ctx->DrawBuffer->_DepthMaxF;

   ASSERT(depthMax > 0);

   /* Compute scale and bias values. This is really driver-specific
    * and should be maintained elsewhere if at all.
    * NOTE: RasterPos uses this.
    */
   _math_matrix_viewport(&ctx->Viewport._WindowMap,
                         ctx->Viewport.X, ctx->Viewport.Y,
                         ctx->Viewport.Width, ctx->Viewport.Height,
                         ctx->Viewport.Near, ctx->Viewport.Far,
                         depthMax);
}


/**
 * Update derived multisample state.
 */
static void
update_multisample(GLcontext *ctx)
{
   ctx->Multisample._Enabled = GL_FALSE;
   if (ctx->Multisample.Enabled &&
       ctx->DrawBuffer &&
       ctx->DrawBuffer->Visual.sampleBuffers)
      ctx->Multisample._Enabled = GL_TRUE;
}


/**
 * Update derived color/blend/logicop state.
 */
static void
update_color(GLcontext *ctx)
{
   /* This is needed to support 1.1's RGB logic ops AND
    * 1.0's blending logicops.
    */
   ctx->Color._LogicOpEnabled = RGBA_LOGICOP_ENABLED(ctx);
}


/*
 * Check polygon state and set DD_TRI_CULL_FRONT_BACK and/or DD_TRI_OFFSET
 * in ctx->_TriangleCaps if needed.
 */
static void
update_polygon(GLcontext *ctx)
{
   ctx->_TriangleCaps &= ~(DD_TRI_CULL_FRONT_BACK | DD_TRI_OFFSET);

   if (ctx->Polygon.CullFlag && ctx->Polygon.CullFaceMode == GL_FRONT_AND_BACK)
      ctx->_TriangleCaps |= DD_TRI_CULL_FRONT_BACK;

   if (   ctx->Polygon.OffsetPoint
       || ctx->Polygon.OffsetLine
       || ctx->Polygon.OffsetFill)
      ctx->_TriangleCaps |= DD_TRI_OFFSET;
}


/**
 * Update the ctx->_TriangleCaps bitfield.
 * XXX that bitfield should really go away someday!
 * This function must be called after other update_*() functions since
 * there are dependencies on some other derived values.
 */
#if 0
static void
update_tricaps(GLcontext *ctx, GLbitfield new_state)
{
   ctx->_TriangleCaps = 0;

   /*
    * Points
    */
   if (1/*new_state & _NEW_POINT*/) {
      if (ctx->Point.SmoothFlag)
         ctx->_TriangleCaps |= DD_POINT_SMOOTH;
      if (ctx->Point.Size != 1.0F)
         ctx->_TriangleCaps |= DD_POINT_SIZE;
      if (ctx->Point._Attenuated)
         ctx->_TriangleCaps |= DD_POINT_ATTEN;
   }

   /*
    * Lines
    */
   if (1/*new_state & _NEW_LINE*/) {
      if (ctx->Line.SmoothFlag)
         ctx->_TriangleCaps |= DD_LINE_SMOOTH;
      if (ctx->Line.StippleFlag)
         ctx->_TriangleCaps |= DD_LINE_STIPPLE;
      if (ctx->Line.Width != 1.0)
         ctx->_TriangleCaps |= DD_LINE_WIDTH;
   }

   /*
    * Polygons
    */
   if (1/*new_state & _NEW_POLYGON*/) {
      if (ctx->Polygon.SmoothFlag)
         ctx->_TriangleCaps |= DD_TRI_SMOOTH;
      if (ctx->Polygon.StippleFlag)
         ctx->_TriangleCaps |= DD_TRI_STIPPLE;
      if (ctx->Polygon.FrontMode != GL_FILL
          || ctx->Polygon.BackMode != GL_FILL)
         ctx->_TriangleCaps |= DD_TRI_UNFILLED;
      if (ctx->Polygon.CullFlag
          && ctx->Polygon.CullFaceMode == GL_FRONT_AND_BACK)
         ctx->_TriangleCaps |= DD_TRI_CULL_FRONT_BACK;
      if (ctx->Polygon.OffsetPoint ||
          ctx->Polygon.OffsetLine ||
          ctx->Polygon.OffsetFill)
         ctx->_TriangleCaps |= DD_TRI_OFFSET;
   }

   /*
    * Lighting and shading
    */
   if (ctx->Light.Enabled && ctx->Light.Model.TwoSide)
      ctx->_TriangleCaps |= DD_TRI_LIGHT_TWOSIDE;
   if (ctx->Light.ShadeModel == GL_FLAT)
      ctx->_TriangleCaps |= DD_FLATSHADE;
   if (NEED_SECONDARY_COLOR(ctx))
      ctx->_TriangleCaps |= DD_SEPARATE_SPECULAR;

   /*
    * Stencil
    */
   if (ctx->Stencil._TestTwoSide)
      ctx->_TriangleCaps |= DD_TRI_TWOSTENCIL;
}
#endif


/**
 * Compute derived GL state.
 * If __GLcontextRec::NewState is non-zero then this function \b must
 * be called before rendering anything.
 *
 * Calls dd_function_table::UpdateState to perform any internal state
 * management necessary.
 * 
 * \sa _mesa_update_modelview_project(), _mesa_update_texture(),
 * _mesa_update_buffer_bounds(),
 * _mesa_update_lighting() and _mesa_update_tnl_spaces().
 */
void
_mesa_update_state_locked( GLcontext *ctx )
{
   GLbitfield new_state = ctx->NewState;

   if (MESA_VERBOSE & VERBOSE_STATE)
      _mesa_print_state("_mesa_update_state", new_state);

   if (new_state & _NEW_PROGRAM)
      update_program( ctx );

   if (new_state & (_NEW_MODELVIEW|_NEW_PROJECTION))
      _mesa_update_modelview_project( ctx, new_state );

   if (new_state & (_NEW_PROGRAM|_NEW_TEXTURE|_NEW_TEXTURE_MATRIX))
      _mesa_update_texture( ctx, new_state );

   if (new_state & (_NEW_BUFFERS | _NEW_COLOR | _NEW_PIXEL))
      _mesa_update_framebuffer(ctx);

   if (new_state & (_NEW_SCISSOR | _NEW_BUFFERS | _NEW_VIEWPORT))
      _mesa_update_draw_buffer_bounds( ctx );

   if (new_state & _NEW_POLYGON)
      update_polygon( ctx );

   if (new_state & _NEW_LIGHT)
      _mesa_update_lighting( ctx );

   if (new_state & _NEW_STENCIL)
      _mesa_update_stencil( ctx );

   if (new_state & _IMAGE_NEW_TRANSFER_STATE)
      _mesa_update_pixel( ctx, new_state );

   if (new_state & _DD_NEW_SEPARATE_SPECULAR)
      update_separate_specular( ctx );

   if (new_state & (_NEW_ARRAY | _NEW_PROGRAM))
      update_arrays( ctx );

   if (new_state & (_NEW_BUFFERS | _NEW_VIEWPORT))
      update_viewport_matrix(ctx);

   if (new_state & _NEW_MULTISAMPLE)
      update_multisample( ctx );

   if (new_state & _NEW_COLOR)
      update_color( ctx );

#if 0
   if (new_state & (_NEW_POINT | _NEW_LINE | _NEW_POLYGON | _NEW_LIGHT
                    | _NEW_STENCIL | _DD_NEW_SEPARATE_SPECULAR))
      update_tricaps( ctx, new_state );
#endif

   if (ctx->FragmentProgram._MaintainTexEnvProgram) {
      if (new_state & (_NEW_TEXTURE | _DD_NEW_SEPARATE_SPECULAR | _NEW_FOG))
	 _mesa_UpdateTexEnvProgram(ctx);
   }

   /* ctx->_NeedEyeCoords is now up to date.
    *
    * If the truth value of this variable has changed, update for the
    * new lighting space and recompute the positions of lights and the
    * normal transform.
    *
    * If the lighting space hasn't changed, may still need to recompute
    * light positions & normal transforms for other reasons.
    */
   if (new_state & _MESA_NEW_NEED_EYE_COORDS) 
      _mesa_update_tnl_spaces( ctx, new_state );

   /*
    * Give the driver a chance to act upon the new_state flags.
    * The driver might plug in different span functions, for example.
    * Also, this is where the driver can invalidate the state of any
    * active modules (such as swrast_setup, swrast, tnl, etc).
    *
    * Set ctx->NewState to zero to avoid recursion if
    * Driver.UpdateState() has to call FLUSH_VERTICES().  (fixed?)
    */
   new_state = ctx->NewState;
   ctx->NewState = 0;
   ctx->Driver.UpdateState(ctx, new_state);
   ctx->Array.NewState = 0;
}


/* This is the usual entrypoint for state updates:
 */
void
_mesa_update_state( GLcontext *ctx )
{
   _mesa_lock_context_textures(ctx);
   _mesa_update_state_locked(ctx);
   _mesa_unlock_context_textures(ctx);
}



/*@}*/