Have camera callbacks take canvas coordinates as doubles.

5 files changed, 13 insertions, 23 deletions

diff --git a/libdimension/cameras.c b/libdimension/cameras.c
index dfe4708..9e0642f 100644
--- a/libdimension/cameras.c
+++ b/libdimension/cameras.c
@@ -26,9 +26,7 @@
 
 /* Perspective camera ray callback */
 static dmnsn_line dmnsn_perspective_camera_ray_fn(const dmnsn_camera *camera,
-                                                  const dmnsn_canvas *canvas,
-                                                  unsigned int x,
-                                                  unsigned int y);
+                                                  double x, double y);
 
 /* Create a new perspective camera.  Rays are aimed from the origin to a screen
    located on the z = 1 frame, from (-0.5, -0.5) to (0.5, 0.5).  Rays are then
@@ -73,8 +71,7 @@ dmnsn_set_perspective_camera_trans(dmnsn_camera *camera, dmnsn_matrix T)
 /* Perspective camera ray callback */
 static dmnsn_line
 dmnsn_perspective_camera_ray_fn(const dmnsn_camera *camera,
-                                const dmnsn_canvas *canvas,
-                                unsigned int x, unsigned int y)
+                                double x, double y)
 {
   dmnsn_matrix *trans = camera->ptr;
   dmnsn_line l;
@@ -83,9 +80,7 @@ dmnsn_perspective_camera_ray_fn(const dmnsn_camera *camera,
   l.x0 = dmnsn_vector_construct(0.0, 0.0, 0.0);
 
   /* Aim at the z = 1 plane */
-  l.n.x = ((double)x)/(canvas->x - 1) - 0.5;
-  l.n.y = ((double)y)/(canvas->y - 1) - 0.5;
-  l.n.z = 1.0;
+  l.n = dmnsn_vector_construct(x - 0.5, y - 0.5, 1.0);
 
   return dmnsn_matrix_line_mul(*trans, l);
 }
diff --git a/libdimension/dimension/camera.h b/libdimension/dimension/camera.h
index 3e6da4f..5e7b253 100644
--- a/libdimension/dimension/camera.h
+++ b/libdimension/dimension/camera.h
@@ -30,8 +30,7 @@ typedef struct dmnsn_camera dmnsn_camera;
 
 /* Camera callback types */
 typedef dmnsn_line dmnsn_camera_ray_fn(const dmnsn_camera *camera,
-                                       const dmnsn_canvas *canvas,
-                                       unsigned int x, unsigned int y);
+                                       double x, double y);
 
 struct dmnsn_camera {
   /* Callback functions */
diff --git a/libdimension/raytrace.c b/libdimension/raytrace.c
index 470af4f..df61d6b 100644
--- a/libdimension/raytrace.c
+++ b/libdimension/raytrace.c
@@ -213,7 +213,9 @@ dmnsn_raytrace_scene_impl(dmnsn_progress *progress, dmnsn_scene *scene,
 
       if (scene->quality >= DMNSN_RENDER_OBJECTS) {
         /* Get the ray corresponding to the (x,y)'th pixel */
-        ray = (*scene->camera->ray_fn)(scene->camera, scene->canvas, x, y);
+        ray = (*scene->camera->ray_fn)(scene->camera,
+                                       ((double)x)/(scene->canvas->x - 1),
+                                       ((double)y)/(scene->canvas->y - 1));
         /* Shoot a ray */
         color = dmnsn_raytrace_shoot(scene, color, ray);
       }
diff --git a/libdimensionxx/camera.cpp b/libdimensionxx/camera.cpp
index 3536e54..d483ba3 100644
--- a/libdimensionxx/camera.cpp
+++ b/libdimensionxx/camera.cpp
@@ -32,9 +32,9 @@ namespace Dimension
 
   // Return the result of the dmnsn_camera*'s ray callback
   Line
-  Camera::ray(const Canvas& canvas, unsigned int x, unsigned int y)
+  Camera::ray(double x, double y)
   {
-    return Line((*dmnsn()->ray_fn)(dmnsn(), canvas.dmnsn(), x, y));
+    return Line((*dmnsn()->ray_fn)(dmnsn(), x, y));
   }
 
   // Return the wrapped camera
@@ -91,16 +91,10 @@ namespace Dimension
   // Custom camera callbacks
   namespace {
     dmnsn_line
-    ray_fn(const dmnsn_camera *camera, const dmnsn_canvas *canvas,
-           unsigned int x, unsigned int y)
+    ray_fn(const dmnsn_camera *camera, double x, double y)
     {
       Custom_Camera* ccamera = reinterpret_cast<Custom_Camera*>(camera->ptr);
-      // Yes the const_cast is ugly, but there's no other way because C++
-      // doesn't have `const' constructors.  Luckily const Camera's treat their
-      // dmnsn_camera* as a const dmnsn_camera*.
-      return ccamera->ray(
-        Canvas(const_cast<dmnsn_canvas*>(canvas)), x, y
-      ).dmnsn();
+      return ccamera->ray(x, y).dmnsn();
     }
   }
 
diff --git a/libdimensionxx/dimensionxx/camera.hpp b/libdimensionxx/dimensionxx/camera.hpp
index 0f61435..81952d1 100644
--- a/libdimensionxx/dimensionxx/camera.hpp
+++ b/libdimensionxx/dimensionxx/camera.hpp
@@ -33,7 +33,7 @@ namespace Dimension
     virtual ~Camera();
 
     // Camera callback
-    virtual Line ray(const Canvas& canvas, unsigned int x, unsigned int y);
+    virtual Line ray(double x, double y);
 
     // Shallow-copy a derived camera
     virtual Camera* copy() const = 0;
@@ -70,7 +70,7 @@ namespace Dimension
     Custom_Camera();
     virtual ~Custom_Camera();
 
-    virtual Line ray(const Canvas& canvas, unsigned int x, unsigned int y) = 0;
+    virtual Line ray(double x, double y) = 0;
   };
 
   // Array_Element specialization