/* * 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 * THE AUTHORS 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(struct gl_context *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 != 0.0F) ? INV_SQRTF(q) : 1.0F; 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(struct gl_context *ctx, struct tnl_pipeline_stage *stage) { struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb; struct point_stage_data *store; stage->privatePtr = 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 ); 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 */ };