// =========================================================================
// ======================== INITIALIZER CONSTANTS ==========================
__constant float4 zeroed_float4 = {0.0f, 0.0f, 0.0f, 0.0f} ;
__constant float3 zeroed_float3 = {0.0f, 0.0f, 0.0f} ;
__constant float2 zeroed_float2 = {0.0f, 0.0f} ;
__constant int4 zeroed_int4 = {0, 0 , 0 , 0} ;
__constant int3 zeroed_int3 = {0, 0 , 0} ;
__constant int2 zeroed_int2 = {0, 0} ;
// =========================================================================
// ============================ OCTREE CONSTANTS ===========================
// ( X, Y, Z ) mask for the idx
__constant const uchar idx_set_x_mask = 0x1 ;
__constant const uchar idx_set_y_mask = 0x2 ;
__constant const uchar idx_set_z_mask = 0x4 ;
__constant const uchar3 idx_set_mask = {0x1, 0x2, 0x4} ;
__constant const uchar mask_8[8] = {
0x1, 0x2, 0x4, 0x8,
0x10, 0x20, 0x40, 0x80
} ;
// Mask for counting the previous valid bits
__constant const uchar count_mask_8[8] = {
0x1, 0x3, 0x7, 0xF,
0x1F, 0x3F, 0x7F, 0xFF
} ;
// uint64_t manipulation masks
__constant const ulong child_pointer_mask = 0x0000000000007fff ;
__constant const ulong far_bit_mask = 0x8000 ;
__constant const ulong valid_mask = 0xFF0000 ;
__constant const ulong leaf_mask = 0xFF000000 ;
__constant const ulong contour_pointer_mask = 0xFFFFFF00000000 ;
__constant const ulong contour_mask = 0xFF00000000000000 ;
// =========================================================================
// ========================= RAYCASTER CONSTANTS ===========================
constant float4 fog_color = { 0.0f, 0.0f, 0.0f, 0.0f } ;
constant float4 overshoot_color = { 0.00f, 0.00f, 0.00f, 0.00f } ;
constant float4 overshoot_color_2 = { 0.00f, 0.00f, 0.00f, 0.00f } ;
// =========================================================================
// =========================================================================
// =========================================================================
// ========================= HELPER FUNCTIONS ==============================
// Phong + diffuse lighting function for g
// 0 1 2 3 4 5 6 7 8 9
// {r, g, b, i, x, y, z, x ', y ', z '}
float4 view_light ( float4 in_color, float3 light, float4 light_color, float3 view, int3 mask ) {
if ( all ( light == zeroed_float3 ) )
return zeroed_float4 ;
float d = fast_length ( light ) * 0.01f ;
d *= d ;
float diffuse = max ( dot ( normalize ( convert_float3 ( mask ) ) , normalize ( light ) ) , 0.1f ) ;
float specular = 0.0f ;
if ( diffuse > 0.0f ) {
// Small dots of light are caused by floating point error
// flipping bits on the face mask and screwing up this calculation
float3 halfwayVector = normalize ( normalize ( light ) + normalize ( view ) ) ;
float specTmp = max ( dot ( normalize ( convert_float3 ( mask ) ) , halfwayVector ) , 0.0f ) ;
specular = pow ( specTmp, 1.0f ) ;
}
in_color += diffuse * light_color + specular * light_color / d ;
return in_color ;
}
int rand ( int* seed ) // 1 <= *seed < m
{
int const a = 16807 ; //ie 7**5
int const m = 2147483647 ; //ie 2**31-1
*seed = ( ( *seed ) * a ) % m ;
return ( *seed ) ;
}
// =========================================================================
// ========================= OCTREE TRAVERSAL ==============================
struct TraversalState {
int parent_stack_position ;
ulong parent_stack[10] ;
ulong parent_stack_index[10] ;
uchar scale ;
uchar idx_stack[10] ;
ulong current_descriptor ;
ulong current_descriptor_index ;
int3 oct_pos ;
// ====== DEBUG =======
char found ;
} ;
bool get_oct_vox (
int3 position,
global ulong *octree_descriptor_buffer,
global uint *octree_attachment_lookup_buffer,
global ulong *octree_attachment_buffer,
global ulong *settings_buffer
) {
struct TraversalState ts ;
// push the root node to the parent stack
ts.current_descriptor_index = *settings_buffer ;
ts.current_descriptor = octree_descriptor_buffer[ts.current_descriptor_index] ;
ts.scale = 0 ;
ts.found = false ;
ts.parent_stack[ts.scale] = ts.current_descriptor ;
// Set our initial dimension and the position at the corner of the oct to keep track of our position
int dimension = OCTDIM ;
ts.oct_pos = zeroed_int3 ;
// While we are not at the required resolution
// Traverse down by setting the valid/leaf mask to the subvoxel
// Check to see if it is valid
// Yes?
// Check to see if it is a leaf
// No? Break
// Yes? Scale down to the next hierarchy, push the parent to the stack
//
// No?
// Break
while ( dimension > 1 ) {
// So we can be a little bit tricky here and increment our
// array index that holds our masks as we build the idx.
// Adding 1 for X, 2 for Y, and 4 for Z
ts.idx_stack[ts.scale] = 0 ;
// Do the logic steps to find which sub oct we step down into
if ( position.x >= ( dimension / 2 ) + ts.oct_pos.x ) {
// Set our voxel position to the ( 0 , 0 ) of the correct oct
ts.oct_pos.x += ( dimension / 2 ) ;
// Set the idx to represent the move
ts.idx_stack[ts.scale] | = idx_set_x_mask ;
}
if ( position.y >= ( dimension / 2 ) + ts.oct_pos.y ) {
ts.oct_pos.y += ( dimension / 2 ) ;
ts.idx_stack[ts.scale] | = idx_set_y_mask ;
}
if ( position.z >= ( dimension / 2 ) + ts.oct_pos.z ) {
ts.oct_pos.z += ( dimension / 2 ) ;
ts.idx_stack[ts.scale] | = idx_set_z_mask ;
}
int mask_index = ts.idx_stack[ts.scale] ;
// Check to see if we are on a valid oct
if ( ( ts.current_descriptor >> 16 ) & mask_8[mask_index] ) {
// Check to see if it is a leaf
if ( ( ts.current_descriptor >> 24 ) & mask_8[mask_index] ) {
// If it is, then we cannot traverse further as CP 's won 't have been generated
ts.found = true ;
return ts.found ;
}
// If all went well and we found a valid non-leaf oct then we will traverse further down the hierarchy
ts.scale++ ;
dimension /= 2 ;
// Count the number of valid octs that come before and add it to the index to get the position
// Negate it by one as it counts itself
int count = popcount ( ( uchar ) ( ts.current_descriptor >> 16 ) & count_mask_8[mask_index] ) - 1 ;
// access the far point at which the head points too. Determine it 's value, and add
// a count of the valid bits to the index
if ( far_bit_mask & octree_descriptor_buffer[ts.current_descriptor_index] ) {
int far_pointer_index = ts.current_descriptor_index + ( ts.current_descriptor & child_pointer_mask ) ;
ts.current_descriptor_index = octree_descriptor_buffer[far_pointer_index] + count ;
}
// access the element at which head points to and then add the specified number of indices
// to get to the correct child descriptor
else {
ts.current_descriptor_index = ts.current_descriptor_index + ( ts.current_descriptor & child_pointer_mask ) + count ;
}
ts.current_descriptor = octree_descriptor_buffer[ts.current_descriptor_index] ;
ts.parent_stack[ts.scale] = ts.current_descriptor ;
}
else {
// If the oct was not valid, then no CP 's exists any further
// This implicitly says that if it 's non-valid then it must be a leaf!!
// It appears that the traversal is now working but I need
// to focus on how to now take care of the end condition.
// Currently it adds the last parent on the second to lowest
// oct CP. Not sure if thats correct
ts.found = 0 ;
return ts.found ;
}
}
ts.found = 1 ;
return ts.found ;
}
// =========================================================================
// ========================= RAYCASTER ENTRY ===============================
__kernel void raycaster (
global char* map,
constant int3* map_dim,
constant int2* resolution,
global float3* projection_matrix,
global float2* cam_dir,
global float3* cam_pos,
global float* lights,
global int* light_count,
__write_only image2d_t image,
__read_only image2d_t texture_atlas,
constant int2 *atlas_dim,
constant int2 *tile_dim,
global ulong *octree_descriptor_buffer,
global uint *octree_attachment_lookup_buffer,
global ulong *octree_attachment_buffer,
global ulong *settings_buffer
) {
// Get the pixel on the viewport, and find the view matrix ray that matches it
int2 pixel = ( int2 ) ( get_global_id ( 0 ) , get_global_id ( 1 ) ) ;
float3 ray_dir = projection_matrix[pixel.x + ( *resolution ) . x * pixel.y] ;
// Pitch
ray_dir = ( float3 ) (
ray_dir.z * sin ( ( *cam_dir ) . x ) + ray_dir.x * cos ( ( *cam_dir ) . x ) ,
ray_dir.y,
ray_dir.z * cos ( ( *cam_dir ) . x ) - ray_dir.x * sin ( ( *cam_dir ) . x )
) ;
// Yaw
ray_dir = ( float3 ) (
ray_dir.x * cos ( ( *cam_dir ) . y ) - ray_dir.y * sin ( ( *cam_dir ) . y ) ,
ray_dir.x * sin ( ( *cam_dir ) . y ) + ray_dir.y * cos ( ( *cam_dir ) . y ) ,
ray_dir.z
) ;
if ( any ( ray_dir == zeroed_float3 ) )
return ;
// Setup the voxel step based on what direction the ray is pointing
int3 voxel_step = {1, 1 , 1} ;
voxel_step *= ( ray_dir > 0 ) - ( ray_dir < 0 ) ;
// Setup the voxel coords from the camera origin
int3 voxel = convert_int3_rtn ( *cam_pos ) ;
//voxel = voxel + convert_int3 ( *cam_pos < 0.0f ) ;
// Delta T is the units a ray must travel along an axis in order to
// traverse an integer split
float3 delta_t = fabs ( 1.0f / ray_dir ) ;
// Intersection T is the collection of the next intersection points
// for all 3 axis XYZ. We take the full positive cardinality when
// subtracting the floor, so we must transfer the sign over from
// the voxel step
float3 offset = delta_t * ( ( *cam_pos ) - ceil ( *cam_pos ) ) ;
float3 intersection_t = offset* convert_float3 ( voxel_step ) ;
// When we transfer the sign over, we get the correct direction of
// the offset, but we merely transposed over the value instead of mirroring
// it over the axis like we want. So here, isless returns a boolean if intersection_t
// is less than 0 which dictates whether or not we subtract the delta which in effect
// mirrors the offset
intersection_t -= delta_t * convert_float3 ( isless ( intersection_t, 0 ) ) ;
int distance_traveled = 0 ;
int max_distance = 700 ;
uint bounce_count = 0 ;
int3 face_mask = { 0 , 0 , 0 } ;
int voxel_data = 0 ;
float3 face_position = zeroed_float3 ;
float4 voxel_color= zeroed_float4 ;
float2 tile_face_position = zeroed_float2 ;
float3 sign = zeroed_float3 ;
float4 color_accumulator = zeroed_float4 ;
float fog_distance = 0.0f ;
bool shadow_ray = false ;
// Andrew Woo 's raycasting algo
while ( distance_traveled < max_distance && bounce_count < 2 ) {
// Fancy no branch version of the logic step
face_mask = intersection_t.xyz <= min ( intersection_t.yzx, intersection_t.zxy ) ;
intersection_t += delta_t * fabs ( convert_float3 ( face_mask.xyz ) ) ;
voxel.xyz += voxel_step.xyz * face_mask.xyz ;
// =======================================================================================================================================
// =======================================================================================================================================
// =======================================================================================================================================
// uchar prev_val = traversal_state.idx_stack[traversal_state.scale] ;
// uint8_t this_face_mask = 0 ;
//
// // Check the voxel face that we traversed
// // and increment the idx in the idx stack
// if ( face_mask.x ) {
// this_face_mask = Octree::idx_set_x_mask ;
// }
// else if ( face_mask.y ) {
// this_face_mask = Octree::idx_set_y_mask ;
// }
// else if ( face_mask.z ) {
// this_face_mask = Octree::idx_set_z_mask ;
// }
//
// traversal_state.idx_stack[traversal_state.scale] ^= this_face_mask ;
//
// // Mask index is the 1D index 'd value of the idx for interaction with the valid / leaf masks
// int mask_index = traversal_state.idx_stack[traversal_state.scale] ;
//
// // Whether or not the next oct we want to enter in the current CD 's valid mask is 1 or 0
// bool is_valid = false ;
//
// // TODO: Rework this logic so we don 't have this bodgy if
// if ( mask_index > prev_val )
// is_valid = ( traversal_state.parent_stack[traversal_state.parent_stack_position] >> 16 ) & mask_8[mask_index] ;
//
// // Check to see if the idx increased or decreased
// // If it decreased
// // Pop up the stack until the oct that the idx flip is valid and we landed on a valid oct
// while ( mask_index < prev_val | | !is_valid ) {
//
// jump_power *= 2 ;
//
// // Keep track of the 0th edge of out current oct
// traversal_state.oct_pos.x = floor ( voxel.x / 2 ) * jump_power ;
// traversal_state.oct_pos.y = floor ( voxel.y / 2 ) * jump_power ;
// traversal_state.oct_pos.z = floor ( voxel.z / 2 ) * jump_power ;
//
// // Clear and pop the idx stack
// traversal_state.idx_stack[traversal_state.scale] = 0 ;
//
// // Scale is now set to the oct above. Be wary of this
// traversal_state.scale-- ;
//
// // Update the prev_val for our new idx
// prev_val = traversal_state.idx_stack[traversal_state.scale] ;
//
// // Clear and pop the parent stack, maybe off by one error?
// traversal_state.parent_stack_index[traversal_state.parent_stack_position] = 0 ;
// traversal_state.parent_stack[traversal_state.parent_stack_position] = 0 ;
// traversal_state.parent_stack_position-- ;
//
// // Set the current CD to the one on top of the stack
// traversal_state.current_descriptor =
// traversal_state.parent_stack[traversal_state.parent_stack_position] ;
//
// // Apply the face mask to the new idx for the while check
// traversal_state.idx_stack[traversal_state.scale] ^= this_face_mask ;
//
// // Get the mask index of the new idx and check the valid status
// mask_index = traversal_state.idx_stack[traversal_state.scale] ;
// is_valid = ( traversal_state.parent_stack[traversal_state.parent_stack_position] >> 16 ) & mask_8[mask_index] ;
// }
//
// // At this point parent_stack[position] is at the CD of an oct with a valid oct at the leaf indicated by the current
// // idx in the idx stack scale
//
// // While we haven 't bottomed out and the oct we 're looking at is valid
// while ( jump_power > 1 && is_valid ) {
//
// // If all went well and we found a valid non-leaf oct then we will traverse further down the hierarchy
// traversal_state.scale++ ;
// jump_power /= 2 ;
//
// // Count the number of valid octs that come before and add it to the index to get the position
// // Negate it by one as it counts itself
// int count = count_bits ( ( uint8_t ) ( traversal_state.parent_stack[traversal_state.parent_stack_position] >> 16 ) & count_mask_8[mask_index] ) - 1 ;
//
// // If this CD had the far bit set
// if ( far_bit_mask & descriptor_buffer[traversal_state.parent_stack_index[traversal_state.parent_stack_position]] ) {
//
// // access the far point at which the head points too. Determine it 's value, and add
// // the count of the valid bits in the current CD to the index
// uint64_t far_pointer_index =
// traversal_state.parent_stack_index[traversal_state.parent_stack_position] + // current index +
// ( traversal_state.parent_stack[traversal_state.parent_stack_position] & child_pointer_mask ) ; // the relative prt to the far ptr
//
// // Get the absolute ptr from the far ptr and add the count to get the CD that we want
// traversal_state.parent_stack_index[traversal_state.parent_stack_position + 1] = descriptor_buffer[far_pointer_index] + count ;
// }
// // If this CD doesn 't have the far bit set, access the element at which head points to
// // and then add the specified number of indices to get to the correct child descriptor
// else {
// traversal_state.parent_stack_index[traversal_state.parent_stack_position + 1] =
// traversal_state.parent_stack_index[traversal_state.parent_stack_position] + // The current index to this CD
// ( traversal_state.parent_stack[traversal_state.parent_stack_position] & child_pointer_mask ) + count ; // The relative dist + the number of bits that were valid
// }
//
// // Now that we have the index set we can increase our parent stack position to the next level and
// // retrieve the value of its CD
// traversal_state.parent_stack_position++ ;
// traversal_state.parent_stack[traversal_state.parent_stack_position] = descriptor_buffer[traversal_state.parent_stack_index[traversal_state.parent_stack_position]] ;
//
// // Unlike the single shot DFS, it makes a bit more sense to have this at the tail of the while loop
// // Do the logic steps to find which sub oct we step down into
// if ( voxel.x >= ( jump_power / 2 ) + traversal_state.oct_pos.x ) {
//
// // Set our voxel position to the ( 0 , 0 ) of the correct oct
// traversal_state.oct_pos.x += ( jump_power / 2 ) ;
//
// // Set the idx to represent the move
// traversal_state.idx_stack[traversal_state.scale] | = idx_set_x_mask ;
//
// }
// if ( voxel.y >= ( jump_power / 2 ) + traversal_state.oct_pos.y ) {
//
// traversal_state.oct_pos.y += ( jump_power / 2 ) ;
// traversal_state.idx_stack[traversal_state.scale] | = idx_set_y_mask ;
// }
// if ( voxel.z >= ( jump_power / 2 ) + traversal_state.oct_pos.z ) {
//
// traversal_state.oct_pos.z += ( jump_power / 2 ) ;
// traversal_state.idx_stack[traversal_state.scale] | = idx_set_z_mask ;
// }
//
// // Update the mask index with the new voxel we walked down to, and then check it 's valid status
// mask_index = traversal_state.idx_stack[traversal_state.scale] ;
// is_valid = ( traversal_state.parent_stack[traversal_state.parent_stack_position] >> 16 ) & mask_8[mask_index] ;
//
// }
// =======================================================================================================================================
// =======================================================================================================================================
// =======================================================================================================================================
// Test for out of bounds contions, add fog
if ( any ( voxel >= *map_dim ) | | any ( voxel < 0 ) ) {
voxel.xyz -= voxel_step.xyz * face_mask.xyz ;
color_accumulator = mix ( fog_color, voxel_color, 1.0f - max ( distance_traveled / 700.0f, 0.0f ) ) ;
color_accumulator.w *= 4 ;
break ;
}
constant int vox_dim = OCTDIM ;
// If we hit a voxel
// if ( voxel.x < ( *map_dim ) . x && voxel.y < ( *map_dim ) . x && voxel.z < ( *map_dim ) . x ) {
// if ( get_oct_vox (
// voxel,
// octree_descriptor_buffer,
// octree_attachment_lookup_buffer,
// octree_attachment_buffer,
// settings_buffer
// ) ) {
// voxel_data = 5 ;
// } else {
// voxel_data = 0 ;
// }
// } else {
voxel_data = map[voxel.x + ( *map_dim ) . x * ( voxel.y + ( *map_dim ) . z * ( voxel.z ) ) ] ;
//}
if ( voxel_data == 5 | | voxel_data == 6 ) {
// Determine where on the 2d plane the ray intersected
face_position = zeroed_float3 ;
tile_face_position = zeroed_float2 ;
sign = ( 1.0f, 1.0f, 1.0f ) ;
// First determine the percent of the way the ray is towards the next intersection_t
// in relation to the xyz position on the plane
if ( face_mask.x == -1 ) {
sign.x *= -1.0 ;
// the next intersection for this plane - the last intersection of the passed plane / delta of this plane
// basically finds how far in on the other 2 axis we are when the ray traversed the plane
float z_percent = ( intersection_t.z - ( intersection_t.x - delta_t.x ) ) / delta_t.z ;
float y_percent = ( intersection_t.y - ( intersection_t.x - delta_t.x ) ) / delta_t.y ;
// Since we intersected face x, we know that we are at the face ( 1.0 )
// I think the 1.001f rendering bug is the ray thinking it 's within the voxel
// even though it 's sitting on the very edge
face_position = ( float3 ) ( 1.00001f, y_percent, z_percent ) ;
tile_face_position = face_position.yz ;
}
else if ( face_mask.y == -1 ) {
sign.y *= -1.0 ;
float x_percent = ( intersection_t.x - ( intersection_t.y - delta_t.y ) ) / delta_t.x ;
float z_percent = ( intersection_t.z - ( intersection_t.y - delta_t.y ) ) / delta_t.z ;
face_position = ( float3 ) ( x_percent, 1.00001f, z_percent ) ;
tile_face_position = face_position.xz ;
}
else if ( face_mask.z == -1 ) {
sign.z *= -1.0 ;
float x_percent = ( intersection_t.x - ( intersection_t.z - delta_t.z ) ) / delta_t.x ;
float y_percent = ( intersection_t.y - ( intersection_t.z - delta_t.z ) ) / delta_t.y ;
face_position = ( float3 ) ( x_percent, y_percent, 1.00001f ) ;
tile_face_position = face_position.xy ;
}
// Because the raycasting process is agnostic to the quadrant
// it 's working in, we need to transpose the sign over to the face positions.
// If we don 't it will think that it is always working in the ( 1 , 1 , 1 ) quadrant
// and will just "copy" the quadrant. This includes shadows as they use the face_position
// in order to cast the intersection ray!!
face_position.x = select ( ( face_position.x ) , ( -face_position.x + 1.0f ) , ( int ) ( ray_dir.x > 0 ) ) ;
tile_face_position.x = select ( ( tile_face_position.x ) , ( -tile_face_position.x + 1.0f ) , ( int ) ( ray_dir.x < 0 ) ) ;
if ( ray_dir.y > 0 ) {
face_position.y = -face_position.y + 1 ;
} else {
tile_face_position.x = 1.0 - tile_face_position.x ;
// We run into the Hairy ball problem, so we need to define
// a special case for the zmask
if ( face_mask.z == -1 ) {
tile_face_position.x = 1.0f - tile_face_position.x ;
tile_face_position.y = 1.0f - tile_face_position.y ;
}
}
face_position.z = select ( ( face_position.z ) , ( -face_position.z + 1.0f ) , ( int ) ( ray_dir.z > 0 ) ) ;
tile_face_position.y = select ( ( tile_face_position.y ) , ( -tile_face_position.y + 1.0f ) , ( int ) ( ray_dir.z < 0 ) ) ;
// Now we detect what type of of voxel we intersected and decide whether
// to bend the ray, send out a light intersection ray, or add texture color
// TEXTURE HIT + SHADOW RAY REDIRECTION
if ( voxel_data == 5 && !shadow_ray ) {
shadow_ray = true ;
voxel_color.xyz += ( float3 ) read_imagef (
texture_atlas,
convert_int2 ( tile_face_position * convert_float2 ( *atlas_dim / *tile_dim ) ) +
convert_int2 ( ( float2 ) ( 5 , 0 ) * convert_float2 ( *atlas_dim / *tile_dim ) )
) . xyz/2 ;
color_accumulator = view_light (
voxel_color,
( convert_float3 ( voxel ) + face_position ) - ( float3 ) ( lights[4], lights[5], lights[6] ) ,
( float4 ) ( lights[0], lights[1], lights[2], lights[3] ) ,
( convert_float3 ( voxel ) + face_position ) - ( *cam_pos ) ,
face_mask * voxel_step
) ;
fog_distance = distance_traveled ;
max_distance = distance_traveled + fast_distance ( convert_float3 ( voxel ) , ( float3 ) ( lights[4], lights[5], lights[6] ) ) ;
float3 hit_pos = convert_float3 ( voxel ) + face_position ;
ray_dir = normalize ( ( float3 ) ( lights[4], lights[5], lights[6] ) - hit_pos ) ;
if ( any ( ray_dir == zeroed_float3 ) )
return ;
voxel -= voxel_step * face_mask ;
voxel_step = ( 1 , 1 , 1 ) * ( ( ray_dir > 0 ) - ( ray_dir < 0 ) ) ;
delta_t = fabs ( 1.0f / ray_dir ) ;
intersection_t = delta_t * ( ( hit_pos ) -floor ( hit_pos ) ) * convert_float3 ( voxel_step ) ;
intersection_t += delta_t * -convert_float3 ( isless ( intersection_t, 0 ) ) ;
// REFLECTION
} else if ( voxel_data == 6 && !shadow_ray ) {
voxel_color.xyz += ( float3 ) read_imagef (
texture_atlas,
convert_int2 ( tile_face_position * convert_float2 ( *atlas_dim / *tile_dim ) ) +
convert_int2 ( ( float2 ) ( 3 , 4 ) * convert_float2 ( *atlas_dim / *tile_dim ) )
) . xyz/4 ;
voxel_color.w -= 0.0f ;
float3 hit_pos = convert_float3 ( voxel ) + face_position ;
ray_dir *= sign ;
if ( any ( ray_dir == zeroed_float3 ) )
return ;
voxel -= voxel_step * face_mask ;
voxel_step = ( 1 , 1 , 1 ) ;
voxel_step *= ( ray_dir > 0 ) - ( ray_dir < 0 ) ;
delta_t = fabs ( 1.0f / ray_dir ) ;
intersection_t = delta_t * ( ( hit_pos ) -floor ( hit_pos ) ) * convert_float3 ( voxel_step ) ;
intersection_t += delta_t * -convert_float3 ( isless ( intersection_t, 0 ) ) ;
bounce_count += 1 ;
// SHADOW RAY HIT
} else {
color_accumulator.w = 0.1f ;
break ;
}
}
// At the bottom of the while loop, add one to the distance ticker
distance_traveled++ ;
}
color_accumulator = mix ( fog_color, color_accumulator, 1.0f - max ( fog_distance / 700.0f, 0.0f ) ) ;
write_imagef (
image,
pixel,
color_accumulator
) ;
return ;
}