/**
* 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;
}
