| /* |
| * Mesa 3-D graphics library |
| * |
| * 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 OR COPYRIGHT HOLDERS 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 "c99_math.h" |
| #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) ? (1.0f / 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 */ |
| }; |