that was a pain. Got it working on windows again. MSVC was being really

picky about a few errors. Good thing though, I'm not really sure why
clang + osx let me be that lax with memory

kernels/minimal_kernel.cl

@@ -0,0 +1,175 @@
+__kernel void min_kern(
+        global char* map,
+        global int3* map_dim,
+        global int2* resolution,
+        global float3* projection_matrix,
+        global float3* cam_dir,
+        global float3* cam_pos,
+        __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];
+    //printf("%i === %f, %f, %f\n", id, ray_dir.x, ray_dir.y, ray_dir.z);
+
+    // Y axis, pitch
+    //ray_dir.x = ray_dir.z * sin(cam_dir->y) + ray_dir.x * cos(cam_dir->y);
+    //ray_dir.y = ray_dir.y;
+    //ray_dir.z = ray_dir.z * cos(cam_dir->y) - ray_dir.x * sin(cam_dir->y);
+
+
+    ray_dir = (float3)(
+            ray_dir.z * sin(cam_dir->y) + ray_dir.x * cos(cam_dir->y),
+            ray_dir.y,
+            ray_dir.z * cos(cam_dir->y) - ray_dir.x * sin(cam_dir->y)
+    );
+
+    // Z axis, yaw
+    //ray_dir.x = ray_dir.x * cos(cam_dir->z) - ray_dir.y * sin(cam_dir->z);
+    //ray_dir.y = ray_dir.x * sin(cam_dir->z) + ray_dir.y * cos(cam_dir->z);
+    //ray_dir.z = ray_dir.z;
+
+    ray_dir = (float3)(
+            ray_dir.x * cos(cam_dir->z) - ray_dir.y * sin(cam_dir->z),
+            ray_dir.x * sin(cam_dir->z) + ray_dir.y * cos(cam_dir->z),
+            ray_dir.z
+    );
+
+
+    // Setup the voxel step based on what direction the ray is pointing
+    int3 voxel_step = {1, 1, 1};
+    voxel_step.x *= (ray_dir.x > 0) - (ray_dir.x < 0);
+    voxel_step.y *= (ray_dir.y > 0) - (ray_dir.y < 0);
+    voxel_step.z *= (ray_dir.z > 0) - (ray_dir.z < 0);
+
+    // Setup the voxel coords from the camera origin
+    int3 voxel = {
+            floor(cam_pos->x),
+            floor(cam_pos->y),
+            floor(cam_pos->z)
+    };
+
+    // 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.x),
+            fabs(1.0f / ray_dir.y),
+            fabs(1.0f / ray_dir.z)
+    };
+
+    // Intersection T is the collection of the next intersection points
+    // for all 3 axis XYZ.
+    float3 intersection_t = {
+            delta_t.x,
+            delta_t.y,
+            delta_t.z
+    };
+
+
+    int dist = 0;
+    int face = -1;
+    // X:0, Y:1, Z:2
+
+    // Andrew Woo's raycasting algo
+    do {
+        if ((intersection_t.x) < (intersection_t.y)) {
+            if ((intersection_t.x) < (intersection_t.z)) {
+
+                face = 0;
+                voxel.x += voxel_step.x;
+                intersection_t.x = intersection_t.x + delta_t.x;
+            } else {
+
+                face = 2;
+                voxel.z += voxel_step.z;
+                intersection_t.z = intersection_t.z + delta_t.z;
+            }
+        } else {
+            if ((intersection_t.y) < (intersection_t.z)) {
+
+                face = 1;
+                voxel.y += voxel_step.y;
+                intersection_t.y = intersection_t.y + delta_t.y;
+            } else {
+
+                face = 2;
+                voxel.z += voxel_step.z;
+                intersection_t.z = intersection_t.z + delta_t.z;
+            }
+        }
+
+        // If the ray went out of bounds
+        if (voxel.z >= map_dim->z) {
+            write_imagef(image, pixel, (float4)(.5, .50, .00, 1));
+            return;
+        }
+        if (voxel.x >= map_dim->x) {
+            write_imagef(image, pixel, (float4)(.00, .00, .99, 1));
+            return;
+        }
+        if (voxel.y >= map_dim->x) {
+            write_imagef(image, pixel, (float4)(.00, .44, .00, 1));
+            return;
+        }
+
+        if (voxel.x < 0) {
+            write_imagef(image, pixel, (float4)(.99, .00, .99, 1));
+            return;
+        }
+        if (voxel.y < 0) {
+            write_imagef(image, pixel, (float4)(.99, .99, .00, 1));
+            return;
+        }
+        if (voxel.z < 0) {
+            write_imagef(image, pixel, (float4)(.00, .99, .99, 1));
+            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 (id == 240000)
+            printf("%i, %i, %i\n", voxel.x, voxel.y, voxel.z);
+
+        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));
+                if (id == 249000)
+                    printf("%i\n", voxel_data);
+                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)(.10, .30, .80, 1.00));
+                return;
+            case 6:
+                write_imagef(image, pixel, (float4)(.30, .80, .10, 1.00));
+                return;
+        }
+
+        dist++;
+    } while (dist < 600);
+
+
+    write_imagef(image, pixel, (float4)(.00, .00, .00, .00));
+    return;
+
+    //printf("%i %i -- ", id, map[id]);
+    //printf("%i, %i, %i\n", map_dim->x, map_dim->y, map_dim->z);
+    //printf("\n%i\nX: %f\nY: %f\nZ: %f\n", id, projection_matrix[id].x, projection_matrix[id].y, projection_matrix[id].z);
+    //printf("%f, %f, %f\n", cam_dir->x, cam_dir->y, cam_dir->z);
+    //printf("%f, %f, %f\n", cam_pos->x, cam_pos->y, cam_pos->z);
+
+}