viewport: consistently use floats for viewports

OpenGL < 4.0 only supports integer based viewports and internally we
have a mixture of code using floats and integers for viewports. This
patch switches all viewports throughout clutter and cogl to be
represented using floats considering that in the future we may want to
take advantage of floating point viewports with modern hardware/drivers.

clutter/clutter-actor.c

@@ -1968,7 +1968,7 @@ _clutter_actor_fully_transform_vertices (ClutterActor *self,
   ClutterActor *stage;
   CoglMatrix modelview;
   CoglMatrix projection;
-  int viewport[4];
+  float viewport[4];
 
   g_return_val_if_fail (CLUTTER_IS_ACTOR (self), FALSE);
 
@@ -11786,7 +11786,7 @@ clutter_actor_get_paint_box (ClutterActor    *self,
   const ClutterPaintVolume *pv;
   CoglMatrix modelview;
   CoglMatrix projection;
-  int viewport[4];
+  float viewport[4];
   ClutterPaintVolume projected_pv;
 
   g_return_val_if_fail (CLUTTER_IS_ACTOR (self), FALSE);

clutter/clutter-paint-volume-private.h

@@ -113,7 +113,7 @@ void                _clutter_paint_volume_transform            (ClutterPaintVolu
 void                _clutter_paint_volume_project              (ClutterPaintVolume *pv,
                                                                 const CoglMatrix   *modelview,
                                                                 const CoglMatrix   *projection,
-                                                                const int          *viewport);
+                                                                const float        *viewport);
 void                _clutter_paint_volume_get_bounding_box     (ClutterPaintVolume *pv,
                                                                 ClutterActorBox    *box);
 void                _clutter_paint_volume_axis_align           (ClutterPaintVolume *pv);

clutter/clutter-paint-volume.c

@@ -651,7 +651,7 @@ void
 _clutter_paint_volume_project (ClutterPaintVolume *pv,
                                const CoglMatrix *modelview,
                                const CoglMatrix *projection,
-                               const int *viewport)
+                               const float *viewport)
 {
   int transform_count;
 

clutter/clutter-private.h

@@ -221,11 +221,17 @@ GType _clutter_layout_manager_get_child_meta_type (ClutterLayoutManager *manager
 
 void  _clutter_util_fully_transform_vertices (const CoglMatrix    *modelview,
                                               const CoglMatrix    *projection,
-                                              const int           *viewport,
+                                              const float         *viewport,
                                               const ClutterVertex *vertices_in,
                                               ClutterVertex       *vertices_out,
                                               int                  n_vertices);
 
+typedef struct _ClutterPlane
+{
+  CoglVector3 v0;
+  CoglVector3 n;
+} ClutterPlane;
+
 G_END_DECLS
 
 #endif /* __CLUTTER_PRIVATE_H__ */

clutter/clutter-stage-private.h

@@ -41,15 +41,15 @@ void                _clutter_stage_get_projection_matrix (ClutterStage
                                                           CoglMatrix            *projection);
 void                _clutter_stage_dirty_projection      (ClutterStage          *stage);
 void                _clutter_stage_set_viewport          (ClutterStage          *stage,
-                                                          int                    x,
+                                                          float                  x,
-                                                          int                    y,
+                                                          float                  y,
-                                                          int                    width,
+                                                          float                  width,
-                                                          int                    height);
+                                                          float                  height);
 void                _clutter_stage_get_viewport          (ClutterStage          *stage,
-                                                          int                   *x,
+                                                          float                 *x,
-                                                          int                   *y,
+                                                          float                 *y,
-                                                          int                   *width,
+                                                          float                 *width,
-                                                          int                   *height);
+                                                          float                 *height);
 void                _clutter_stage_dirty_viewport        (ClutterStage          *stage);
 void                _clutter_stage_maybe_setup_viewport  (ClutterStage          *stage);
 void                _clutter_stage_maybe_relayout        (ClutterActor          *stage);

clutter/clutter-stage.c

@@ -115,7 +115,7 @@ struct _ClutterStagePrivate
   ClutterColor        color;
   ClutterPerspective  perspective;
   CoglMatrix          projection;
-  int                 viewport[4];
+  float               viewport[4];
   ClutterFog          fog;
 
   gchar              *title;
@@ -1880,14 +1880,19 @@ _clutter_stage_dirty_projection (ClutterStage *stage)
  * (XXX: If we were to make this API public then we might want to do
  *  add that property.)
  *
+ * Note: currently this interface only support integer precision
+ * offsets and sizes for viewports but the interface takes floats because
+ * OpenGL 4.0 has introduced floating point viewports which we might
+ * want to expose via this API eventually.
+ *
  * Since: 1.6
  */
 void
 _clutter_stage_set_viewport (ClutterStage *stage,
-                             int           x,
+                             float         x,
-                             int           y,
+                             float         y,
-                             int           width,
+                             float         width,
-                             int           height)
+                             float         height)
 {
   ClutterStagePrivate *priv;
 
@@ -1943,10 +1948,10 @@ _clutter_stage_dirty_viewport (ClutterStage *stage)
  */
 void
 _clutter_stage_get_viewport (ClutterStage *stage,
-                             int          *x,
+                             float        *x,
-                             int          *y,
+                             float        *y,
-                             int          *width,
+                             float        *width,
-                             int          *height)
+                             float        *height)
 {
   ClutterStagePrivate *priv;
 
@@ -2753,7 +2758,7 @@ _clutter_stage_maybe_setup_viewport (ClutterStage *stage)
   if (priv->dirty_viewport)
     {
       CLUTTER_NOTE (PAINT,
-                    "Setting up the viewport { w:%d, h:%d }",
+                    "Setting up the viewport { w:%f, h:%f }",
                     priv->viewport[2], priv->viewport[3]);
 
       cogl_set_viewport (priv->viewport[0],

clutter/clutter-util.c

@@ -84,7 +84,7 @@ _clutter_gettext (const gchar *str)
 void
 _clutter_util_fully_transform_vertices (const CoglMatrix *modelview,
                                         const CoglMatrix *projection,
-                                        const int *viewport,
+                                        const float *viewport,
                                         const ClutterVertex *vertices_in,
                                         ClutterVertex *vertices_out,
                                         int n_vertices)

clutter/cogl/cogl/cogl-framebuffer-private.h

@@ -46,10 +46,10 @@ struct _CoglFramebuffer
 
   CoglMatrixStack    *modelview_stack;
   CoglMatrixStack    *projection_stack;
-  int                 viewport_x;
+  float               viewport_x;
-  int                 viewport_y;
+  float               viewport_y;
-  int                 viewport_width;
+  float               viewport_width;
-  int                 viewport_height;
+  float               viewport_height;
 
   CoglClipState       clip_state;
 
@@ -173,25 +173,25 @@ _cogl_framebuffer_set_clip_stack (CoglFramebuffer *framebuffer,
 
 void
 _cogl_framebuffer_set_viewport (CoglFramebuffer *framebuffer,
-                                int x,
+                                float x,
-                                int y,
+                                float y,
-                                int width,
+                                float width,
-                                int height);
+                                float height);
-int
+float
 _cogl_framebuffer_get_viewport_x (CoglFramebuffer *framebuffer);
 
-int
+float
 _cogl_framebuffer_get_viewport_y (CoglFramebuffer *framebuffer);
 
-int
+float
 _cogl_framebuffer_get_viewport_width (CoglFramebuffer *framebuffer);
 
-int
+float
 _cogl_framebuffer_get_viewport_height (CoglFramebuffer *framebuffer);
 
 void
 _cogl_framebuffer_get_viewport4fv (CoglFramebuffer *framebuffer,
-                                   int *viewport);
+                                   float *viewport);
 
 CoglMatrixStack *
 _cogl_framebuffer_get_modelview_stack (CoglFramebuffer *framebuffer);

clutter/cogl/cogl/cogl-framebuffer.c

@@ -499,10 +499,10 @@ _cogl_framebuffer_set_clip_stack (CoglFramebuffer *framebuffer,
 
 void
 _cogl_framebuffer_set_viewport (CoglFramebuffer *framebuffer,
-                                int x,
+                                float x,
-                                int y,
+                                float y,
-                                int width,
+                                float width,
-                                int height)
+                                float height)
 {
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
 
@@ -523,32 +523,33 @@ _cogl_framebuffer_set_viewport (CoglFramebuffer *framebuffer,
     ctx->dirty_gl_viewport = TRUE;
 }
 
-int
+float
 _cogl_framebuffer_get_viewport_x (CoglFramebuffer *framebuffer)
 {
   return framebuffer->viewport_x;
 }
 
-int
+float
 _cogl_framebuffer_get_viewport_y (CoglFramebuffer *framebuffer)
 {
   return framebuffer->viewport_y;
 }
 
-int
+float
 _cogl_framebuffer_get_viewport_width (CoglFramebuffer *framebuffer)
 {
   return framebuffer->viewport_width;
 }
 
-int
+float
 _cogl_framebuffer_get_viewport_height (CoglFramebuffer *framebuffer)
 {
   return framebuffer->viewport_height;
 }
 
 void
-_cogl_framebuffer_get_viewport4fv (CoglFramebuffer *framebuffer, int *viewport)
+_cogl_framebuffer_get_viewport4fv (CoglFramebuffer *framebuffer,
+                                   float *viewport)
 {
   viewport[0] = framebuffer->viewport_x;
   viewport[1] = framebuffer->viewport_y;
@@ -1290,7 +1291,7 @@ _cogl_framebuffer_flush_state (CoglFramebuffer *draw_buffer,
 
   if (ctx->dirty_gl_viewport)
     {
-      int gl_viewport_y;
+      float gl_viewport_y;
 
       /* Convert the Cogl viewport y offset to an OpenGL viewport y offset
        * NB: OpenGL defines its window and viewport origins to be bottom
@@ -1303,7 +1304,7 @@ _cogl_framebuffer_flush_state (CoglFramebuffer *draw_buffer,
         gl_viewport_y = draw_buffer->height -
           (draw_buffer->viewport_y + draw_buffer->viewport_height);
 
-      COGL_NOTE (OPENGL, "Calling glViewport(%d, %d, %d, %d)",
+      COGL_NOTE (OPENGL, "Calling glViewport(%f, %f, %f, %f)",
                  draw_buffer->viewport_x,
                  gl_viewport_y,
                  draw_buffer->viewport_width,

clutter/cogl/cogl/cogl-journal.c

@@ -1552,7 +1552,7 @@ entry_to_screen_polygon (const CoglJournalEntry *entry,
   CoglMatrixStack *projection_stack;
   CoglMatrix projection;
   int i;
-  int viewport[4];
+  float viewport[4];
 
   poly[0] = vertices[0];
   poly[1] = vertices[1];

clutter/cogl/cogl/cogl-matrix-mesa.c

@@ -1251,13 +1251,15 @@ _math_matrix_translate (CoglMatrix *matrix, float x, float y, float z)
  * Transforms Normalized Device Coords to window/Z values.
  */
 void
-_math_matrix_viewport (CoglMatrix *matrix, int x, int y, int width, int height,
+_math_matrix_viewport (CoglMatrix *matrix,
+                       float x, float y,
+                       float width, float height,
                        float zNear, float zFar, float depthMax)
 {
   float *m = (float *)matrix;
-  m[MAT_SX] = (float)width / 2.0f;
+  m[MAT_SX] = width / 2.0f;
   m[MAT_TX] = m[MAT_SX] + x;
-  m[MAT_SY] = (float) height / 2.0f;
+  m[MAT_SY] = height / 2.0f;
   m[MAT_TY] = m[MAT_SY] + y;
   m[MAT_SZ] = depthMax * ((zFar - zNear) / 2.0f);
   m[MAT_TZ] = depthMax * ((zFar - zNear) / 2.0f + zNear);

clutter/cogl/cogl/cogl-matrix-mesa.h

@@ -134,7 +134,7 @@ _math_matrix_frustum (CoglMatrix *matrix,
 
 void
 _math_matrix_viewport (CoglMatrix *matrix,
-                       int x, int y, int width, int height,
+                       float x, float y, float width, float height,
                        float z_near, float z_far, float depth_max);
 
 void

clutter/cogl/cogl/cogl-texture.c

@@ -929,7 +929,7 @@ cogl_texture_set_region (CoglHandle       handle,
 static void
 do_texture_draw_and_read (CoglHandle   handle,
                           CoglBitmap  *target_bmp,
-                          GLint       *viewport)
+                          float       *viewport)
 {
   int         bpp;
   float       rx1, ry1;
@@ -1036,7 +1036,7 @@ _cogl_texture_draw_and_read (CoglHandle   handle,
 {
   int        bpp;
   CoglFramebuffer *framebuffer;
-  int        viewport[4];
+  float viewport[4];
   CoglBitmap *alpha_bmp;
   CoglMatrixStack *projection_stack;
   CoglMatrixStack *modelview_stack;
@@ -1064,10 +1064,10 @@ _cogl_texture_draw_and_read (CoglHandle   handle,
   _cogl_matrix_stack_push (projection_stack);
   _cogl_matrix_stack_load_identity (projection_stack);
   _cogl_matrix_stack_ortho (projection_stack,
-                            0, (float)(viewport[2]),
+                            0, viewport[2],
-                            (float)(viewport[3]), 0,
+                            viewport[3], 0,
-                            (float)(0),
+                            0,
-                            (float)(100));
+                            100);
 
   modelview_stack = _cogl_framebuffer_get_modelview_stack (framebuffer);
   _cogl_matrix_stack_push (modelview_stack);

clutter/cogl/cogl/cogl.c

@@ -407,19 +407,14 @@ _cogl_features_available_private (CoglFeatureFlagsPrivate features)
  * _cogl_framebuffer_get_viewport* functions public.
  */
 void
-cogl_get_viewport (float v[4])
+cogl_get_viewport (float viewport[4])
 {
   CoglFramebuffer *framebuffer;
-  int viewport[4];
-  int i;
 
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
 
   framebuffer = _cogl_get_draw_buffer ();
   _cogl_framebuffer_get_viewport4fv (framebuffer, viewport);
-
-  for (i = 0; i < 4; i++)
-    v[i] = viewport[i];
 }
 
 void

clutter/cogl/cogl/cogl.h

@@ -1281,9 +1281,6 @@ _cogl_check_extension (const char *name, const char *ext);
 void
 _cogl_set_indirect_context  (gboolean indirect);
 
-void
-_cogl_set_viewport (int x, int y, int width, int height);
-
 gboolean
 _cogl_check_driver_valid (GError **error);