From a0c4815433ccd57322f4f7703ca35e9ccfa59250 Mon Sep 17 00:00:00 2001 From: marha Date: Thu, 8 Oct 2009 13:15:52 +0000 Subject: Added MesaLib-7.6 --- mesalib/src/mesa/tnl/t_vb_fog.c | 277 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 277 insertions(+) create mode 100644 mesalib/src/mesa/tnl/t_vb_fog.c (limited to 'mesalib/src/mesa/tnl/t_vb_fog.c') diff --git a/mesalib/src/mesa/tnl/t_vb_fog.c b/mesalib/src/mesa/tnl/t_vb_fog.c new file mode 100644 index 000000000..f3a7bd49f --- /dev/null +++ b/mesalib/src/mesa/tnl/t_vb_fog.c @@ -0,0 +1,277 @@ +/* + * Mesa 3-D graphics library + * Version: 6.5 + * + * Copyright (C) 1999-2006 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. + * + * Authors: + * Keith Whitwell + */ + + +#include "main/glheader.h" +#include "main/colormac.h" +#include "main/context.h" +#include "main/macros.h" +#include "main/imports.h" +#include "main/mtypes.h" + +#include "math/m_xform.h" + +#include "t_context.h" +#include "t_pipeline.h" + + +struct fog_stage_data { + GLvector4f fogcoord; /* has actual storage allocated */ +}; + +#define FOG_STAGE_DATA(stage) ((struct fog_stage_data *)stage->privatePtr) + +#define FOG_EXP_TABLE_SIZE 256 +#define FOG_MAX (10.0) +#define EXP_FOG_MAX .0006595 +#define FOG_INCR (FOG_MAX/FOG_EXP_TABLE_SIZE) +static GLfloat exp_table[FOG_EXP_TABLE_SIZE]; +static GLfloat inited = 0; + +#if 1 +#define NEG_EXP( result, narg ) \ +do { \ + GLfloat f = (GLfloat) (narg * (1.0/FOG_INCR)); \ + GLint k = (GLint) f; \ + if (k > FOG_EXP_TABLE_SIZE-2) \ + result = (GLfloat) EXP_FOG_MAX; \ + else \ + result = exp_table[k] + (f-k)*(exp_table[k+1]-exp_table[k]); \ +} while (0) +#else +#define NEG_EXP( result, narg ) \ +do { \ + result = exp(-narg); \ +} while (0) +#endif + + +/** + * Initialize the exp_table[] lookup table for approximating exp(). + */ +static void +init_static_data( void ) +{ + GLfloat f = 0.0F; + GLint i = 0; + for ( ; i < FOG_EXP_TABLE_SIZE ; i++, f += FOG_INCR) { + exp_table[i] = EXPF(-f); + } + inited = 1; +} + + +/** + * Compute per-vertex fog blend factors from fog coordinates by + * evaluating the GL_LINEAR, GL_EXP or GL_EXP2 fog function. + * Fog coordinates are distances from the eye (typically between the + * near and far clip plane distances). + * Note that fogcoords may be negative, if eye z is source absolute + * value must be taken earlier. + * Fog blend factors are in the range [0,1]. + */ +static void +compute_fog_blend_factors(GLcontext *ctx, GLvector4f *out, const GLvector4f *in) +{ + GLfloat end = ctx->Fog.End; + GLfloat *v = in->start; + GLuint stride = in->stride; + GLuint n = in->count; + GLfloat (*data)[4] = out->data; + GLfloat d; + GLuint i; + + out->count = in->count; + + switch (ctx->Fog.Mode) { + case GL_LINEAR: + if (ctx->Fog.Start == ctx->Fog.End) + d = 1.0F; + else + d = 1.0F / (ctx->Fog.End - ctx->Fog.Start); + for ( i = 0 ; i < n ; i++, STRIDE_F(v, stride)) { + const GLfloat z = *v; + GLfloat f = (end - z) * d; + data[i][0] = CLAMP(f, 0.0F, 1.0F); + } + break; + case GL_EXP: + d = ctx->Fog.Density; + for ( i = 0 ; i < n ; i++, STRIDE_F(v,stride)) { + const GLfloat z = *v; + NEG_EXP( data[i][0], d * z ); + } + break; + case GL_EXP2: + d = ctx->Fog.Density*ctx->Fog.Density; + for ( i = 0 ; i < n ; i++, STRIDE_F(v, stride)) { + const GLfloat z = *v; + NEG_EXP( data[i][0], d * z * z ); + } + break; + default: + _mesa_problem(ctx, "Bad fog mode in make_fog_coord"); + return; + } +} + + +static GLboolean +run_fog_stage(GLcontext *ctx, struct tnl_pipeline_stage *stage) +{ + TNLcontext *tnl = TNL_CONTEXT(ctx); + struct vertex_buffer *VB = &tnl->vb; + struct fog_stage_data *store = FOG_STAGE_DATA(stage); + GLvector4f *input; + + + if (!ctx->Fog.Enabled) + return GL_TRUE; + + if (ctx->Fog.FogCoordinateSource == GL_FRAGMENT_DEPTH_EXT && !ctx->VertexProgram._Current) { + GLuint i; + GLfloat *coord; + /* Fog is computed from vertex or fragment Z values */ + /* source = VB->ObjPtr or VB->EyePtr coords */ + /* dest = VB->AttribPtr[_TNL_ATTRIB_FOG] = fog stage private storage */ + VB->AttribPtr[_TNL_ATTRIB_FOG] = &store->fogcoord; + + if (!ctx->_NeedEyeCoords) { + /* compute fog coords from object coords */ + const GLfloat *m = ctx->ModelviewMatrixStack.Top->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. + */ + _mesa_dotprod_tab[VB->ObjPtr->size]( (GLfloat *) input->data, + 4 * sizeof(GLfloat), + VB->ObjPtr, plane ); + + input->count = VB->ObjPtr->count; + + /* make sure coords are really positive + NOTE should avoid going through array twice */ + coord = input->start; + for (i = 0; i < input->count; i++) { + *coord = FABSF(*coord); + STRIDE_F(coord, input->stride); + } + } + else { + /* fog coordinates = eye Z coordinates - need to copy for ABS */ + input = &store->fogcoord; + + if (VB->EyePtr->size < 2) + _mesa_vector4f_clean_elem( VB->EyePtr, VB->Count, 2 ); + + input->stride = 4 * sizeof(GLfloat); + input->count = VB->EyePtr->count; + coord = VB->EyePtr->start; + for (i = 0 ; i < VB->EyePtr->count; i++) { + input->data[i][0] = FABSF(coord[2]); + STRIDE_F(coord, VB->EyePtr->stride); + } + } + } + else { + /* use glFogCoord() coordinates */ + input = VB->AttribPtr[_TNL_ATTRIB_FOG]; /* source data */ + + /* input->count may be one if glFogCoord was only called once + * before glBegin. But we need to compute fog for all vertices. + */ + input->count = VB->ObjPtr->count; + + VB->AttribPtr[_TNL_ATTRIB_FOG] = &store->fogcoord; /* dest data */ + } + + if (tnl->_DoVertexFog) { + /* compute blend factors from fog coordinates */ + compute_fog_blend_factors( ctx, VB->AttribPtr[_TNL_ATTRIB_FOG], input ); + } + else { + /* results = incoming fog coords (compute fog per-fragment later) */ + VB->AttribPtr[_TNL_ATTRIB_FOG] = input; + } + + VB->FogCoordPtr = VB->AttribPtr[_TNL_ATTRIB_FOG]; + return GL_TRUE; +} + + + +/* Called the first time stage->run() is invoked. + */ +static GLboolean +alloc_fog_data(GLcontext *ctx, struct tnl_pipeline_stage *stage) +{ + TNLcontext *tnl = TNL_CONTEXT(ctx); + struct fog_stage_data *store; + stage->privatePtr = MALLOC(sizeof(*store)); + store = FOG_STAGE_DATA(stage); + if (!store) + return GL_FALSE; + + _mesa_vector4f_alloc( &store->fogcoord, 0, tnl->vb.Size, 32 ); + + if (!inited) + init_static_data(); + + return GL_TRUE; +} + + +static void +free_fog_data(struct tnl_pipeline_stage *stage) +{ + struct fog_stage_data *store = FOG_STAGE_DATA(stage); + if (store) { + _mesa_vector4f_free( &store->fogcoord ); + FREE( store ); + stage->privatePtr = NULL; + } +} + + +const struct tnl_pipeline_stage _tnl_fog_coordinate_stage = +{ + "build fog coordinates", /* name */ + NULL, /* private_data */ + alloc_fog_data, /* dtr */ + free_fog_data, /* dtr */ + NULL, /* check */ + run_fog_stage /* run -- initially set to init. */ +}; -- cgit v1.2.3