/** * Examine current GL state and set the store->NormalTransform pointer * to point to the appropriate normal transformation routine. */ static void validate_normal_stage(GLcontext *ctx, struct tnl_pipeline_stage *stage) { struct normal_stage_data *store = NORMAL_STAGE_DATA(stage); if (ctx->VertexProgram._Enabled || (!ctx->Light.Enabled && !(ctx->Texture._GenFlags & TEXGEN_NEED_NORMALS))) { store->NormalTransform = NULL; return; } if (ctx->_NeedEyeCoords) { /* Eye coordinates are needed, for whatever reasons. * Do lighting in eye coordinates, as the GL spec says. */ GLuint transform = NORM_TRANSFORM_NO_ROT; if (_math_matrix_has_rotation(ctx->ModelviewMatrixStack.Top)) { /* need to do full (3x3) matrix transform */ transform = NORM_TRANSFORM; } if (ctx->Transform.Normalize) { store->NormalTransform = _mesa_normal_tab[transform | NORM_NORMALIZE]; } else if (ctx->Transform.RescaleNormals && ctx->_ModelViewInvScale != 1.0) { store->NormalTransform = _mesa_normal_tab[transform | NORM_RESCALE]; } else { store->NormalTransform = _mesa_normal_tab[transform]; } } else { /* We don't need eye coordinates. * Do lighting in object coordinates. Thus, we don't need to fully * transform normal vectors (just leave them in object coordinates) * but we still need to do normalization/rescaling if enabled. */ if (ctx->Transform.Normalize) { store->NormalTransform = _mesa_normal_tab[NORM_NORMALIZE]; } else if (!ctx->Transform.RescaleNormals && ctx->_ModelViewInvScale != 1.0) { store->NormalTransform = _mesa_normal_tab[NORM_RESCALE]; } else { store->NormalTransform = NULL; } } }
/** * Allocate stage's private data (storage for transformed normals). */ static GLboolean alloc_normal_data(GLcontext *ctx, struct tnl_pipeline_stage *stage) { TNLcontext *tnl = TNL_CONTEXT(ctx); struct normal_stage_data *store; stage->privatePtr = _mesa_malloc(sizeof(*store)); store = NORMAL_STAGE_DATA(stage); if (!store) return GL_FALSE; _mesa_vector4f_alloc( &store->normal, 0, tnl->vb.Size, 32 ); return GL_TRUE; }
static GLboolean run_normal_stage(GLcontext *ctx, struct tnl_pipeline_stage *stage) { struct normal_stage_data *store = NORMAL_STAGE_DATA(stage); struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb; const GLfloat *lengths; if (!store->NormalTransform) return GL_TRUE; /* We can only use the display list's saved normal lengths if we've * got a transformation matrix with uniform scaling. */ if (_math_matrix_is_general_scale(ctx->ModelviewMatrixStack.Top)) lengths = NULL; else lengths = VB->NormalLengthPtr; store->NormalTransform( ctx->ModelviewMatrixStack.Top, ctx->_ModelViewInvScale, VB->AttribPtr[_TNL_ATTRIB_NORMAL], /* input normals */ lengths, &store->normal ); /* resulting normals */ if (VB->AttribPtr[_TNL_ATTRIB_NORMAL]->count > 1) { store->normal.stride = 4 * sizeof(GLfloat); } else { store->normal.stride = 0; } VB->AttribPtr[_TNL_ATTRIB_NORMAL] = &store->normal; VB->NormalPtr = &store->normal; VB->NormalLengthPtr = NULL; /* no longer valid */ return GL_TRUE; }