/**
* Compute the offset of a pixel block.
*
* x, y, z, y_stride, z_stride are vectors, and they refer to pixels.
*
* Returns the relative offset and i,j sub-block coordinates
*/
void
lp_build_sample_offset(struct lp_build_context *bld,
const struct util_format_description *format_desc,
LLVMValueRef x,
LLVMValueRef y,
LLVMValueRef z,
LLVMValueRef y_stride,
LLVMValueRef z_stride,
LLVMValueRef *out_offset,
LLVMValueRef *out_i,
LLVMValueRef *out_j)
{
LLVMValueRef x_stride;
LLVMValueRef offset;
x_stride = lp_build_const_vec(bld->gallivm, bld->type,
format_desc->block.bits/8);
lp_build_sample_partial_offset(bld,
format_desc->block.width,
x, x_stride,
&offset, out_i);
if (y && y_stride) {
LLVMValueRef y_offset;
lp_build_sample_partial_offset(bld,
format_desc->block.height,
y, y_stride,
&y_offset, out_j);
offset = lp_build_add(bld, offset, y_offset);
}
else {
*out_j = bld->zero;
}
if (z && z_stride) {
LLVMValueRef z_offset;
LLVMValueRef k;
lp_build_sample_partial_offset(bld,
1, /* pixel blocks are always 2D */
z, z_stride,
&z_offset, &k);
offset = lp_build_add(bld, offset, z_offset);
}
*out_offset = offset;
}
/**
* Build LLVM code for texture coord wrapping, for nearest filtering,
* for scaled integer texcoords.
* \param block_length is the length of the pixel block along the
* coordinate axis
* \param coord the incoming texcoord (s,t,r or q) scaled to the texture size
* \param length the texture size along one dimension
* \param stride pixel stride along the coordinate axis (in bytes)
* \param is_pot if TRUE, length is a power of two
* \param wrap_mode one of PIPE_TEX_WRAP_x
* \param out_offset byte offset for the wrapped coordinate
* \param out_i resulting sub-block pixel coordinate for coord0
*/
static void
lp_build_sample_wrap_nearest_int(struct lp_build_sample_context *bld,
unsigned block_length,
LLVMValueRef coord,
LLVMValueRef length,
LLVMValueRef stride,
boolean is_pot,
unsigned wrap_mode,
LLVMValueRef *out_offset,
LLVMValueRef *out_i)
{
struct lp_build_context *int_coord_bld = &bld->int_coord_bld;
LLVMBuilderRef builder = bld->gallivm->builder;
LLVMValueRef length_minus_one;
length_minus_one = lp_build_sub(int_coord_bld, length, int_coord_bld->one);
switch(wrap_mode) {
case PIPE_TEX_WRAP_REPEAT:
if(is_pot)
coord = LLVMBuildAnd(builder, coord, length_minus_one, "");
else {
/* Add a bias to the texcoord to handle negative coords */
LLVMValueRef bias = lp_build_mul_imm(int_coord_bld, length, 1024);
coord = LLVMBuildAdd(builder, coord, bias, "");
coord = LLVMBuildURem(builder, coord, length, "");
}
break;
case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
coord = lp_build_max(int_coord_bld, coord, int_coord_bld->zero);
coord = lp_build_min(int_coord_bld, coord, length_minus_one);
break;
case PIPE_TEX_WRAP_CLAMP:
case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
case PIPE_TEX_WRAP_MIRROR_REPEAT:
case PIPE_TEX_WRAP_MIRROR_CLAMP:
case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
default:
assert(0);
}
lp_build_sample_partial_offset(int_coord_bld, block_length, coord, stride,
out_offset, out_i);
}
