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.

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);

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,

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];

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);

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

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);

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

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);