Fixed the camera movement so it now take into account sub-voxel movement

Also fixed the distortion around the XY axes

kernels/ray_caster_kernel.cl

@@ -0,0 +1,139 @@
+
+
+float4 white_light(float4 input, float3 light, int3 mask) {
+
+	input.w = input.w + acos(
+		dot(
+			normalize(light),
+			normalize(fabs(convert_float3(mask)))
+			)
+		) / 2;
+
+	return input;
+
+}
+
+__kernel void min_kern(
+        global char* map,
+        global int3* map_dim,
+        global 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
+){
+
+    size_t id = get_global_id(0);
+    int2 pixel = {id % (*resolution).x, id / (*resolution).x};
+    float3 ray_dir = projection_matrix[pixel.x + (*resolution).x * pixel.y];
+
+    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)
+    );
+
+    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
+    );
+
+    // 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(*cam_pos);
+
+    // 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);
+
+	// offset is how far we are into a voxel, enables sub voxel movement
+	float3 offset = ((*cam_pos) - floor(*cam_pos)) * convert_float3(voxel_step);
+    
+	//offset.x += delta_t.x * convert_float((voxel_step.x < 0));
+	//offset -= delta_t * floor(offset / delta_t);
+
+	// Intersection T is the collection of the next intersection points
+    // for all 3 axis XYZ.
+	float3 intersection_t = delta_t * offset;
+
+	if (intersection_t.x < 0) {
+		intersection_t.x += delta_t.x;
+	}
+	if (intersection_t.y < 0) {
+		intersection_t.y += delta_t.y;
+	}
+	if (intersection_t.z < 0) {
+		intersection_t.z += delta_t.z;
+	}
+
+	int2 randoms = { 3, 14 };
+	uint seed = randoms.x + id;
+	uint t = seed ^ (seed << 11);
+	uint result = randoms.y ^ (randoms.y >> 19) ^ (t ^ (t >> 8));
+
+	int max_dist = 500 + result % 50;
+	int dist = 0;
+
+	int3 mask = { 0, 0, 0 };
+
+    // Andrew Woo's raycasting algo
+    do {
+
+		mask = intersection_t.xyz <= min(intersection_t.yzx, intersection_t.zxy);
+		float3 thing = delta_t * fabs(convert_float3(mask.xyz));
+		intersection_t += delta_t * fabs(convert_float3(mask.xyz));
+		voxel.xyz += voxel_step.xyz * mask.xyz;
+
+        // If the ray went out of bounds
+		int3 overshoot = voxel <= *map_dim;
+		int3 undershoot = voxel > 0;
+
+		if (overshoot.x == 0 || overshoot.y == 0 || overshoot.z == 0 || undershoot.x == 0 || undershoot.y == 0){
+			write_imagef(image, pixel, (float4)(.73, .81, .89, 1.0));
+			return;
+		}
+		if (undershoot.z == 0) {
+			write_imagef(image, pixel, (float4)(.14, .30, .50, 1.0));
+			return;
+		}
+
+        // If we hit a voxel
+        int index = voxel.x + (*map_dim).x * (voxel.y + (*map_dim).z * voxel.z);
+        int voxel_data = map[index];
+
+		if (voxel_data != 0) {
+			switch (voxel_data) {
+			case 1:
+				write_imagef(image, pixel, (float4)(.50, .00, .00, 1));
+				return;
+			case 2:
+				write_imagef(image, pixel, (float4)(.00, .50, .40, 1.00));
+				return;
+			case 3:
+				write_imagef(image, pixel, (float4)(.00, .00, .50, 1.00));
+				return;
+			case 4:
+				write_imagef(image, pixel, (float4)(.25, .00, .25, 1.00));
+				return;
+			case 5:
+				//write_imagef(image, pixel, (float4)(.25, .00, .25, 1.00));
+				write_imagef(image, pixel, white_light((float4)(.25, .32, .14, 0.2), (float3)(lights[7], lights[8], lights[9]), mask));
+				return;
+			case 6:
+				write_imagef(image, pixel, (float4)(.30, .80, .10, 1.00));
+				return;
+			}
+		}
+
+        dist++;
+    } while (dist < max_dist);
+
+    write_imagef(image, pixel, (float4)(.73, .81, .89, 1.0));
+    return;
+}