<commit_before>/*

Notes:

Keep this is mind when masking the voxel steps, pretty unintuitive behaviour

	For scalar types, the equality operators return 0 if false and return 1 if true
	For vector types, the equality operators return 0 if false and return -1 if true (i.e. all bits set)
	The equality equal (==) returns 0 if one or both arguments are not a number (NaN).
	The equality not equal (!=) returns 1 (for scalar source operands) or -1 (for vector source
	operands) if one or both arguments are not a number (NaN).

	if statements will take 0 as false and any other integer as true


*/

// =========================================================================
// ======================== 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 };

// =========================================================================
// =========================================================================


#define setting(name)    settings_buffer[name]



// =========================================================================
// ========================= 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 {

	// 0 being the root node
	int parent_stack_position;
	// Holds child descriptors and their indices in the oct array
	ulong parent_stack[10];
	ulong parent_stack_index[10];

	// 0 being the root node
	uchar scale;
	uchar idx_stack[10];

	// current child descriptor for this node
	ulong current_descriptor;
	ulong current_descriptor_index;

	// The position of the (0,0)th vox in an oct
	int3 oct_pos;
	// The width in voxels of the current valid masks being tested
	int resolution;

	// ====== DEBUG =======
	char found;
};

struct TraversalState 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;

	ts.current_descriptor_index = setting(OCTREE_ROOT_INDEX);
	ts.current_descriptor = octree_descriptor_buffer[ts.current_descriptor_index];

	ts.scale = 0;
	ts.parent_stack_position = 0;
	ts.found = false;

	// push the root node to the parent stack
	ts.parent_stack[0] = ts.current_descriptor;

	// Set our initial dimension and the position at the corner of the oct to keep track of our position
	int dimension = setting(OCTDIM);
	ts.resolution = dimension/2;
	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 / vox
		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;

				// Early exit, dimension and resolution are not updated
				return ts;
			}

			// If all went well and we found a valid non-leaf oct then we will traverse further down the hierarchy
			ts.scale++;
			ts.parent_stack_position++;
			ts.oct_pos += select((int3)(0), (int3)(dimension/2), position >= (int3)(dimension/2) + ts.oct_pos);
			dimension /= 2;
			ts.resolution /= 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 pointer 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;
			}

			// Set the current descriptor with the calculated descriptor index
			ts.current_descriptor = octree_descriptor_buffer[ts.current_descriptor_index];

			// And update the data structure with the descriptor and it's index
			ts.parent_stack[ts.parent_stack_position] = ts.current_descriptor;
			ts.parent_stack_index[ts.parent_stack_position] = ts.current_descriptor_index;
		}
		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!!

			// Parent stack is only populated up to the current descriptors parent.
			// So that would be the current voxels grandparent
			ts.oct_pos += select((int3)(0), (int3)(dimension/2), position >= (int3)(dimension/2) + ts.oct_pos);
			ts.found = 0;
			return ts;
		}
	}
	ts.found = 1;
	return ts;
}

// =========================================================================
// ========================= 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
	//                Correct opencl for being stupid and giving us negative for true
	int3 voxel_step = (-1, -1, -1) * ((ray_dir > 0) - (ray_dir < 0));

	// Setup the voxel coords from the camera origin
	// rtn = round towards negative
	int3 voxel = convert_int3_rtn(*cam_pos);
	int3 prev_voxel = voxel;

	// 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 want to 'boost' the intersection_t start point up to
	// the offset, so we get the -(difference) between the int voxel position and the
	// float camera position.
	float3 offset = delta_t * ((*cam_pos) - floor(*cam_pos));

	// Now we apply the inverse of the ray sign. This gives us a negative
	// offset for positive values and vis versa.
	float3 intersection_t = offset * -convert_float3(voxel_step);

	// For negative ray directions the positive value is the correct initial offset
	// For positive rays we now just have to add the delta_t to the negative offset
	// and that will give us the correct positive intersection_t. Don't forget to
	// correct the stupid -1==true
	intersection_t += delta_t * -1 * convert_float3(isless(intersection_t, 0));

	int distance_traveled = 0;
	int max_distance = 100;
	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;
	int vox_dim = setting(OCTDIM);

	struct TraversalState traversal_state;

	traversal_state = get_oct_vox(
			voxel,
			octree_descriptor_buffer,
			octree_attachment_lookup_buffer,
			octree_attachment_buffer,
			settings_buffer);

	int jump_power = traversal_state.resolution;
	int prev_jump_power = jump_power;
	int3 last_oct_pos = (0);

	intersection_t +=
		convert_float3((traversal_state.oct_pos - voxel.xyz) * traversal_state.resolution/2 + traversal_state.resolution/2);

	// Andrew Woo's raycasting algo
	while (distance_traveled < max_distance && bounce_count < 2) {
		// if (jump_power == 2){
		// 	color_accumulator = mix((1.0f, 1.0f, 1.0f, 1.0f), (1.0f, 1.0f, 1.0f, 1.0f), 1.0f - max(distance_traveled / 700.0f, 0.0f));
		// 	color_accumulator.w *= 4;
		// 	break;
		// }
		//   If we hit a voxel
		if (setting(OCTENABLED) == 0 && voxel.x < (*map_dim).x && voxel.y < (*map_dim).x && voxel.z < (*map_dim).x) {

			// True will result in a -1, e.g (0, 0, -1) so negate it to positive
			face_mask = -1 * (intersection_t.xyz <= min(intersection_t.yzx, intersection_t.zxy));

			prev_jump_power = jump_power;
			prev_voxel = voxel;

			voxel.xyz += voxel_step.xyz * face_mask.xyz * convert_int3((traversal_state.oct_pos - voxel.xyz) + traversal_state.resolution);

			// Test for out of bounds contions, add fog
			if (any(voxel >= *map_dim) || any(voxel < 0)){
				voxel.xyz -= voxel_step.xyz * jump_power * face_mask.xyz;
				color_accumulator = mix(fog_color, voxel_color, 1.0f - max(distance_traveled / 700.0f, 0.0f));
				color_accumulator.w *= 4;
				break;
			}

			uchar prev_val = traversal_state.idx_stack[traversal_state.scale];
			uchar this_face_mask = 0;

			// Check the voxel face that we traversed
			if (face_mask.x) {
				this_face_mask = idx_set_x_mask;
			}
			else if (face_mask.y) {
				this_face_mask = idx_set_y_mask;
			}
			else if (face_mask.z) {
				this_face_mask = idx_set_z_mask;
			}

			// and increment the idx in the idx stack
			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
			uchar 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;

			// Check to see if the idx increased or decreased
			// If it decreased, thus invalid
			//		Pop up the stack until the oct that the idx flip is valid and we landed on a valid oct
			if (mask_index > prev_val) // TODO: Rework this logic so we don't have this bodgy if
				is_valid = (traversal_state.parent_stack[traversal_state.parent_stack_position] >> 16) & mask_8[mask_index];

			while (mask_index < prev_val || !is_valid) {

				// Clear and pop the idx stack
				traversal_state.idx_stack[traversal_state.scale] = 0;

				// Clear and pop the parent stack
				traversal_state.parent_stack_index[traversal_state.parent_stack_position] = 0;
				traversal_state.parent_stack[traversal_state.parent_stack_position] = 0;

				// Scale is now set to the oct above. Be wary of this
				jump_power *= 2;
				traversal_state.scale--;
				traversal_state.parent_stack_position--;

				// Update the prev_val for our new idx
				prev_val = traversal_state.idx_stack[traversal_state.scale];

				//traversal_state.oct_pos -= select((int3)0, (int3)jump_power, (int3)(prev_val & idx_set_x_mask, prev_val & idx_set_y_mask, prev_val & idx_set_z_mask));
				// Keep track of the 0th edge of our current oct
				// TODO: Transfer over to selects
				if (prev_val & idx_set_x_mask)
					traversal_state.oct_pos.x -= jump_power;
				if (prev_val & idx_set_y_mask)
					traversal_state.oct_pos.y -= jump_power;
				if (prev_val & idx_set_z_mask)
					traversal_state.oct_pos.z -= jump_power;

				// 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++;

				// 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)(traversal_state.parent_stack[traversal_state.parent_stack_position] >> 16) & count_mask_8[mask_index]) - 1;


				//TODO: REWORK THIS IF STATEMENT, PERF KILLER

				// If this CD had the far bit set
				if (far_bit_mask & octree_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
					uint 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] = octree_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] = octree_descriptor_buffer[traversal_state.parent_stack_index[traversal_state.parent_stack_position]];

				jump_power /= 2;
				// Unlike the single shot DFS, we inherited a valid idx from the upwards traversal. So now we must
				// set the idx at the tail end of this for 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];
			}

			// Add the delta for the jump power and the traversed face
			intersection_t += delta_t * jump_power * fabs(convert_float3(face_mask.xyz));

			// Get the other faces
			int3 other_faces = select((int3)(1,1,1), (int3)(0,0,0), (int3)(face_mask == 1));

			// Get the amount of times we need to multiply the delta t to get to our face
			uint3 multiplier = convert_uint3(abs(traversal_state.oct_pos - last_oct_pos) * (1.0f/prev_jump_power));

			last_oct_pos = traversal_state.oct_pos;

			// Go back to the beginning intersection t's for the non traversed faces
			intersection_t -= delta_t * prev_jump_power * convert_float3(other_faces.xyz);

			// add back the intersection for our current jump power
			intersection_t += delta_t * convert_float3(multiplier) * jump_power * fabs(convert_float3(other_faces.xyz));

			// if (traversal_state.scale == 1 && is_valid){
			// 	voxel_data = 5;
			// 	//voxel.xyz -= voxel_step.xyz * face_mask.xyz;
			// 	color_accumulator = mix((1.0f, 1.0f, 1.0f, 1.0f), (1.0f, 1.0f, 1.0f, 1.0f), 1.0f - max(distance_traveled / 700.0f, 0.0f));
			// 	color_accumulator.w *= 4;
			// 	break;
			// }
			//voxel_data = map[voxel.x + (*map_dim).x * (voxel.y + (*map_dim).z * (voxel.z))];
		}

// =======================================================================
//
// =======================================================================
		else {

			// True will result in a -1, e.g (0, 0, -1) so negate it to positive
			face_mask = -1 * (intersection_t.xyz <= min(intersection_t.yzx, intersection_t.zxy));
			intersection_t += delta_t * convert_float3(face_mask.xyz);
			voxel.xyz += voxel_step.xyz * face_mask.xyz;

			// Test for out of bounds contions, add fog
			if (any(voxel >= *map_dim) || any(voxel < 0)){<commit_msg>looks like the idx checking got broken somehow<commit_after>/*

Notes:

Keep this is mind when masking the voxel steps, pretty unintuitive behaviour

	For scalar types, the equality operators return 0 if false and return 1 if true
	For vector types, the equality operators return 0 if false and return -1 if true (i.e. all bits set)
	The equality equal (==) returns 0 if one or both arguments are not a number (NaN).
	The equality not equal (!=) returns 1 (for scalar source operands) or -1 (for vector source
	operands) if one or both arguments are not a number (NaN).

	if statements will take 0 as false and any other integer as true


*/

// =========================================================================
// ======================== 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 };

// =========================================================================
// =========================================================================


#define setting(name)    settings_buffer[name]



// =========================================================================
// ========================= 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 {

	// 0 being the root node
	int parent_stack_position;
	// Holds child descriptors and their indices in the oct array
	ulong parent_stack[10];
	ulong parent_stack_index[10];

	// 0 being the root node
	uchar scale;
	uchar idx_stack[10];

	// current child descriptor for this node
	ulong current_descriptor;
	ulong current_descriptor_index;

	// The position of the (0,0)th vox in an oct
	int3 oct_pos;
	// The width in voxels of the current valid masks being tested
	int resolution;

	// ====== DEBUG =======
	char found;
};

struct TraversalState 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;

	ts.current_descriptor_index = setting(OCTREE_ROOT_INDEX);
	ts.current_descriptor = octree_descriptor_buffer[ts.current_descriptor_index];

	ts.scale = 0;
	ts.parent_stack_position = 0;
	ts.found = false;

	// push the root node to the parent stack
	ts.parent_stack[0] = ts.current_descriptor;

	// Set our initial dimension and the position at the corner of the oct to keep track of our position
	int dimension = setting(OCTDIM);
	ts.resolution = dimension/2;
	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 / vox
		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;

				// Early exit, dimension and resolution are not updated
				return ts;
			}

			// If all went well and we found a valid non-leaf oct then we will traverse further down the hierarchy
			ts.scale++;
			ts.parent_stack_position++;
			ts.oct_pos += select((int3)(0), (int3)(dimension/2), position >= (int3)(dimension/2) + ts.oct_pos);
			dimension /= 2;
			ts.resolution /= 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 pointer 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;
			}

			// Set the current descriptor with the calculated descriptor index
			ts.current_descriptor = octree_descriptor_buffer[ts.current_descriptor_index];

			// And update the data structure with the descriptor and it's index
			ts.parent_stack[ts.parent_stack_position] = ts.current_descriptor;
			ts.parent_stack_index[ts.parent_stack_position] = ts.current_descriptor_index;
		}
		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!!

			// Parent stack is only populated up to the current descriptors parent.
			// So that would be the current voxels grandparent
			ts.oct_pos += select((int3)(0), (int3)(dimension/2), position >= (int3)(dimension/2) + ts.oct_pos);
			ts.found = 0;
			return ts;
		}
	}
	ts.found = 1;
	return ts;
}

// =========================================================================
// ========================= 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
	//                Correct opencl for being stupid and giving us negative for true
	int3 voxel_step = (-1, -1, -1) * ((ray_dir > 0) - (ray_dir < 0));

	// Setup the voxel coords from the camera origin
	// rtn = round towards negative
	int3 voxel = convert_int3_rtn(*cam_pos);
	int3 prev_voxel = voxel;

	// 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 want to 'boost' the intersection_t start point up to
	// the offset, so we get the -(difference) between the int voxel position and the
	// float camera position.
	float3 offset = delta_t * ((*cam_pos) - floor(*cam_pos));

	// Now we apply the inverse of the ray sign. This gives us a negative
	// offset for positive values and vis versa.
	float3 intersection_t = offset * -convert_float3(voxel_step);

	// For negative ray directions the positive value is the correct initial offset
	// For positive rays we now just have to add the delta_t to the negative offset
	// and that will give us the correct positive intersection_t. Don't forget to
	// correct the stupid -1==true
	intersection_t += delta_t * -1 * convert_float3(isless(intersection_t, 0));

	int distance_traveled = 0;
	int max_distance = 100;
	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;
	int vox_dim = setting(OCTDIM);


	int failsafe = 0;

	struct TraversalState traversal_state;

	traversal_state = get_oct_vox(
			voxel,
			octree_descriptor_buffer,
			octree_attachment_lookup_buffer,
			octree_attachment_buffer,
			settings_buffer);

	int jump_power = traversal_state.resolution;
	int prev_jump_power = jump_power;
	int3 last_oct_pos = (0);

	intersection_t +=
		convert_float3((traversal_state.oct_pos - voxel.xyz) * traversal_state.resolution/2 + traversal_state.resolution/2);

	// Andrew Woo's raycasting algo
	while (distance_traveled < max_distance && bounce_count < 2) {
		// if (jump_power == 2){
		// 	color_accumulator = mix((1.0f, 1.0f, 1.0f, 1.0f), (1.0f, 1.0f, 1.0f, 1.0f), 1.0f - max(distance_traveled / 700.0f, 0.0f));
		// 	color_accumulator.w *= 4;
		// 	break;
		// }
		//   If we hit a voxel
		// Test for out of bounds contions, add fog
		if (any(voxel >= *map_dim) || any(voxel < 0)){
			voxel.xyz -= voxel_step.xyz * jump_power * face_mask.xyz;
			color_accumulator = fog_color;// mix(fog_color, voxel_color, 1.0f);// - max(distance_traveled / 10.0f, 0.0f));
			color_accumulator.w = 1.0f;
			break;
		}
		if (setting(OCTENABLED) == 0 && voxel.x < (*map_dim).x && voxel.y < (*map_dim).x && voxel.z < (*map_dim).x) {

			// True will result in a -1, e.g (0, 0, -1) so negate it to positive
			face_mask = -1 * (intersection_t.xyz <= min(intersection_t.yzx, intersection_t.zxy));

			prev_jump_power = jump_power;
			prev_voxel = voxel;

			// not working, wish I would have commented!!!
			//voxel.xyz += voxel_step.xyz * face_mask.xyz * convert_int3((traversal_state.oct_pos - voxel.xyz) + traversal_state.resolution);
			voxel.xyz += voxel_step.xyz * face_mask.xyz * traversal_state.resolution;

			// Test for out of bounds contions, add fog
			if (any(voxel >= *map_dim) || any(voxel < 0)){
				voxel.xyz -= voxel_step.xyz * jump_power * face_mask.xyz;
				color_accumulator = fog_color;// mix(fog_color, voxel_color, 1.0f);// - max(distance_traveled / 10.0f, 0.0f));
				color_accumulator.w = 1.0f;
				break;
			}

			uchar prev_val = traversal_state.idx_stack[traversal_state.scale];
			uchar this_face_mask = 0;

			// Check the voxel face that we traversed
			if (face_mask.x) {
				this_face_mask = idx_set_x_mask;
			}
			else if (face_mask.y) {
				this_face_mask = idx_set_y_mask;
			}
			else if (face_mask.z) {
				this_face_mask = idx_set_z_mask;
			}

			// and increment the idx in the idx stack
			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
			uchar 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;

			// Check to see if the idx increased or decreased
			// If it decreased, thus invalid
			//		Pop up the stack until the oct that the idx flip is valid and we landed on a valid oct
			if (mask_index > prev_val) // TODO: Rework this logic so we don't have this bodgy if
				is_valid = (traversal_state.parent_stack[traversal_state.parent_stack_position] >> 16) & mask_8[mask_index];

			failsafe = 0;
			while (mask_index < prev_val || !is_valid) {

				// Clear and pop the idx stack
				traversal_state.idx_stack[traversal_state.scale] = 0;

				// Clear and pop the parent stack
				traversal_state.parent_stack_index[traversal_state.parent_stack_position] = 0;
				traversal_state.parent_stack[traversal_state.parent_stack_position] = 0;

				// Scale is now set to the oct above. Be wary of this
				jump_power *= 2;
				traversal_state.scale--;
				traversal_state.parent_stack_position--;

				// Update the prev_val for our new idx
				prev_val = traversal_state.idx_stack[traversal_state.scale];

				// Keep track of the 0th edge of our current oct, select take the dumb MSB truth value for vector types
				// so we just gotta do this component wise, dumb
				traversal_state.oct_pos.x -= select(0, jump_power, (prev_val & idx_set_x_mask));
				traversal_state.oct_pos.y -= select(0, jump_power, (prev_val & idx_set_y_mask));
				traversal_state.oct_pos.z -= select(0, jump_power, (prev_val & idx_set_z_mask));

				// 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];
				failsafe++;
				if (failsafe > 50)
					break;
			}

			// 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
			failsafe = 0;
			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++;

				// 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)(traversal_state.parent_stack[traversal_state.parent_stack_position] >> 16) & count_mask_8[mask_index]) - 1;


				//TODO: REWORK THIS IF STATEMENT, PERF KILLER

				// If this CD had the far bit set
				if (far_bit_mask & octree_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
					uint 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] = octree_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] = octree_descriptor_buffer[traversal_state.parent_stack_index[traversal_state.parent_stack_position]];

				jump_power /= 2;
				// Unlike the single shot DFS, we inherited a valid idx from the upwards traversal. So now we must
				// set the idx at the tail end of this for 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];

				failsafe++;
				if (failsafe > 50)
					break;
			}

			// Add the delta for the jump power and the traversed face
			intersection_t += delta_t * jump_power * fabs(convert_float3(face_mask.xyz));

			// Get the other faces
			int3 other_faces = select((int3)(1,1,1), (int3)(0,0,0), (int3)(face_mask == 1));

			// Get the amount of times we need to multiply the delta t to get to our face
			uint3 multiplier = convert_uint3(abs(traversal_state.oct_pos - last_oct_pos) * (1.0f/prev_jump_power));

			last_oct_pos = traversal_state.oct_pos;

			// Go back to the beginning intersection t's for the non traversed faces
			//intersection_t -= delta_t * prev_jump_power * convert_float3(other_faces.xyz);

			// add back the intersection for our current jump power
			//intersection_t += delta_t * convert_float3(multiplier) * jump_power * fabs(convert_float3(other_faces.xyz));

			// if (traversal_state.scale == 1 && is_valid){
			// 	voxel_data = 5;
			// 	//voxel.xyz -= voxel_step.xyz * face_mask.xyz;
			// 	color_accumulator = mix((1.0f, 1.0f, 1.0f, 1.0f), (1.0f, 1.0f, 1.0f, 1.0f), 1.0f - max(distance_traveled / 700.0f, 0.0f));
			// 	color_accumulator.w *= 4;
			// 	break;
			// }
			//voxel_data = map[voxel.x + (*map_dim).x * (voxel.y + (*map_dim).z * (voxel.z))];
		}

// =======================================================================
//
// =======================================================================
		else {

			// True will result in a -1, e.g (0, 0, -1) so negate it to positive
			face_mask = -1 * (intersection_t.xyz <= min(intersection_t.yzx, intersection_t.zxy));
			intersection_t += delta_t * convert_float3(face_mask.xyz);
			voxel.xyz += voxel_step.xyz * face_mask.xyz;

			// Test for out of bounds contions, add fog
			if (any(voxel >= *map_dim) || any(voxel < 0)){
{'fraction_non_alphanumeric': 0.14489884162854738, 'fraction_numerical': 0.02321294463029972, 'mean_word_length': 3.716324997316733, 'pattern_counts': {'":': 0, '<': 30, '<?xml version=': 0, '>': 64, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 6, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '5258840', 'n_tokens_mistral': 16744, 'n_tokens_neox': 14245, 'n_words': 4471}