diff options
Diffstat (limited to 'src/mesa/tnl/t_vb_fog.c')
| -rw-r--r-- | src/mesa/tnl/t_vb_fog.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/src/mesa/tnl/t_vb_fog.c b/src/mesa/tnl/t_vb_fog.c new file mode 100644 index 00000000000..38a80702ab2 --- /dev/null +++ b/src/mesa/tnl/t_vb_fog.c @@ -0,0 +1,201 @@ +/* $Id: t_vb_fog.c,v 1.1 2000/12/26 05:09:33 keithw Exp $ */ + +/* + * Mesa 3-D graphics library + * Version: 3.5 + * + * Copyright (C) 1999-2000 Brian Paul All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN + * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + * + * Author: + * Keith Whitwell <[email protected]> + */ + + +#include "glheader.h" +#include "colormac.h" +#include "context.h" +#include "macros.h" +#include "mem.h" +#include "mmath.h" +#include "mtypes.h" + +#include "math/m_xform.h" + +#include "t_context.h" +#include "t_pipeline.h" + + +struct fog_stage_data { + GLvector1f fogcoord; /* has actual storage allocated */ + GLvector1f input; /* points into VB->EyePtr Z values */ +}; + +#define FOG_STAGE_DATA(stage) ((struct fog_stage_data *)stage->private) + + + +/* Use lookup table & interpolation? + */ +static void make_win_fog_coords( GLcontext *ctx, GLvector1f *out, + const GLvector1f *in ) +{ + GLfloat end = ctx->Fog.End; + GLfloat *v = in->start; + GLuint stride = in->stride; + GLuint n = in->count; + GLfloat *data = out->data; + GLfloat d; + GLuint i; + + out->count = in->count; + + switch (ctx->Fog.Mode) { + case GL_LINEAR: + d = 1.0F / (ctx->Fog.End - ctx->Fog.Start); + for ( i = 0 ; i < n ; i++, STRIDE_F(v, stride)) + data[i] = (end - ABSF(*v)) * d; + break; + case GL_EXP: + d = -ctx->Fog.Density; + for ( i = 0 ; i < n ; i++, STRIDE_F(v,stride)) + data[i] = exp( d*ABSF(*v) ); + break; + case GL_EXP2: + d = -(ctx->Fog.Density*ctx->Fog.Density); + for ( i = 0 ; i < n ; i++, STRIDE_F(v, stride)) { + GLfloat z = *v; + data[i] = exp( d*z*z ); + } + break; + default: + gl_problem(ctx, "Bad fog mode in make_fog_coord"); + return; + } +} + + +static GLboolean run_fog_stage( GLcontext *ctx, + struct gl_pipeline_stage *stage ) +{ + struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb; + struct fog_stage_data *store = FOG_STAGE_DATA(stage); + GLvector1f *input; + + VB->FogCoordPtr = &store->fogcoord; + + if (stage->changed_inputs == 0) + return GL_TRUE; + + if (ctx->Fog.FogCoordinateSource == GL_FRAGMENT_DEPTH_EXT) { + if (!ctx->_NeedEyeCoords) { + GLfloat *m = ctx->ModelView.m; + GLfloat plane[4]; + + /* Use this to store calculated eye z values: + */ + input = &store->fogcoord; + + plane[0] = m[2]; + plane[1] = m[6]; + plane[2] = m[10]; + plane[3] = m[14]; + + /* Full eye coords weren't required, just calculate the + * eye Z values. + */ + gl_dotprod_tab[0][VB->ObjPtr->size](input->data, sizeof(GLfloat), + VB->ObjPtr, plane, 0 ); + + input->count = VB->ObjPtr->count; + } + else + { + input = &store->input; + + if (VB->EyePtr->size < 2) + gl_vector4f_clean_elem( VB->EyePtr, VB->Count, 2 ); + + input->data = &(VB->EyePtr->data[0][2]); + input->start = VB->EyePtr->start+2; + input->stride = VB->EyePtr->stride; + input->count = VB->EyePtr->count; + } + } else + input = VB->FogCoordPtr; + + make_win_fog_coords( ctx, VB->FogCoordPtr, input ); + return GL_TRUE; +} + +static void check_fog_stage( GLcontext *ctx, struct gl_pipeline_stage *stage ) +{ + stage->active = ctx->Fog.Enabled; + + if (ctx->Fog.FogCoordinateSource == GL_FRAGMENT_DEPTH_EXT) + stage->inputs = VERT_EYE; + else + stage->inputs = VERT_FOG_COORD; +} + + +/* Called the first time stage->run() is invoked. + */ +static GLboolean alloc_fog_data( GLcontext *ctx, + struct gl_pipeline_stage *stage ) +{ + TNLcontext *tnl = TNL_CONTEXT(ctx); + struct fog_stage_data *store; + stage->private = MALLOC(sizeof(*store)); + store = FOG_STAGE_DATA(stage); + if (!store) + return GL_FALSE; + + gl_vector1f_alloc( &store->fogcoord, 0, tnl->vb.Size, 32 ); + gl_vector1f_init( &store->input, 0, 0 ); + + /* Now run the stage. + */ + stage->run = run_fog_stage; + return stage->run( ctx, stage ); +} + + +static void free_fog_data( struct gl_pipeline_stage *stage ) +{ + struct fog_stage_data *store = FOG_STAGE_DATA(stage); + if (store) { + gl_vector1f_free( &store->fogcoord ); + FREE( store ); + stage->private = 0; + } +} + + +const struct gl_pipeline_stage _tnl_fog_coordinate_stage = +{ + "build fog coordinates", + _NEW_FOG, + _NEW_FOG, + 0, 0, VERT_FOG_COORD, /* active, inputs, outputs */ + 0, 0, /* changed_inputs, private_data */ + free_fog_data, /* dtr */ + check_fog_stage, /* check */ + alloc_fog_data /* run -- initially set to init. */ +}; |