diff options
Diffstat (limited to 'mesalib/src/mesa/tnl/t_vb_points.c')
-rw-r--r-- | mesalib/src/mesa/tnl/t_vb_points.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/mesalib/src/mesa/tnl/t_vb_points.c b/mesalib/src/mesa/tnl/t_vb_points.c new file mode 100644 index 000000000..a52505b4b --- /dev/null +++ b/mesalib/src/mesa/tnl/t_vb_points.c @@ -0,0 +1,114 @@ +/* + * Mesa 3-D graphics library + * Version: 7.0 + * + * Copyright (C) 1999-2007 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: + * Brian Paul + */ + +#include "main/glheader.h" +#include "main/mtypes.h" +#include "main/dd.h" +#include "main/imports.h" +#include "t_context.h" +#include "t_pipeline.h" + + +struct point_stage_data { + GLvector4f PointSize; +}; + +#define POINT_STAGE_DATA(stage) ((struct point_stage_data *)stage->privatePtr) + + +/** + * Compute point size for each vertex from the vertex eye-space Z + * coordinate and the point size attenuation factors. + * Only done when point size attenuation is enabled and vertex program is + * disabled. + */ +static GLboolean +run_point_stage(GLcontext *ctx, struct tnl_pipeline_stage *stage) +{ + if (ctx->Point._Attenuated && !ctx->VertexProgram._Current) { + struct point_stage_data *store = POINT_STAGE_DATA(stage); + struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb; + const GLfloat *eyeCoord = (GLfloat *) VB->EyePtr->data + 2; + const GLint eyeCoordStride = VB->EyePtr->stride / sizeof(GLfloat); + const GLfloat p0 = ctx->Point.Params[0]; + const GLfloat p1 = ctx->Point.Params[1]; + const GLfloat p2 = ctx->Point.Params[2]; + const GLfloat pointSize = ctx->Point.Size; + GLfloat (*size)[4] = store->PointSize.data; + GLuint i; + + for (i = 0; i < VB->Count; i++) { + const GLfloat dist = FABSF(*eyeCoord); + const GLfloat q = p0 + dist * (p1 + dist * p2); + const GLfloat atten = (q != 0.0) ? SQRTF(1.0 / q) : 1.0; + size[i][0] = pointSize * atten; /* clamping done in rasterization */ + eyeCoord += eyeCoordStride; + } + + VB->AttribPtr[_TNL_ATTRIB_POINTSIZE] = &store->PointSize; + } + + return GL_TRUE; +} + + +static GLboolean +alloc_point_data(GLcontext *ctx, struct tnl_pipeline_stage *stage) +{ + struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb; + struct point_stage_data *store; + stage->privatePtr = _mesa_malloc(sizeof(*store)); + store = POINT_STAGE_DATA(stage); + if (!store) + return GL_FALSE; + + _mesa_vector4f_alloc( &store->PointSize, 0, VB->Size, 32 ); + return GL_TRUE; +} + + +static void +free_point_data(struct tnl_pipeline_stage *stage) +{ + struct point_stage_data *store = POINT_STAGE_DATA(stage); + if (store) { + _mesa_vector4f_free( &store->PointSize ); + _mesa_free( store ); + stage->privatePtr = NULL; + } +} + + +const struct tnl_pipeline_stage _tnl_point_attenuation_stage = +{ + "point size attenuation", /* name */ + NULL, /* stage private data */ + alloc_point_data, /* alloc data */ + free_point_data, /* destructor */ + NULL, + run_point_stage /* run */ +}; |