From: Robert Bragg <robert@linux.intel.com>
Date: Wed, 18 Feb 2009 18:54:54 +0000 (+0000)
Subject: [Cogl] the cogl_get_*_matrix functions now work with CoglMatrix types
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=34e53736edb3579822ef36f39cce42ca7dc87d70;p=profile%2Fivi%2Fclutter.git

[Cogl] the cogl_get_*_matrix functions now work with CoglMatrix types

Since the CoglMatrix type was added for supporting texture matrices recently
it made sense to be consistent accross the Cogl API and use the Cogl type
over the GL style GLfloat m[16] arrays.
---

diff --git a/README b/README
index 4518210..d689550 100644
--- a/README
+++ b/README
@@ -287,6 +287,9 @@ Release Notes for Clutter 1.0
   density argument isn't just ignored. A cogl_disable_fog function was
   also added.
 
+* cogl_get_*_matrix were changed to use the CoglMatrix type instead of
+  GLfloat m[16] arrays.
+
 Release Notes for Clutter 0.8
 -------------------------------
 
diff --git a/clutter/clutter-actor.c b/clutter/clutter-actor.c
index 9aa3aad..1b9dbc6 100644
--- a/clutter/clutter-actor.c
+++ b/clutter/clutter-actor.c
@@ -867,57 +867,20 @@ fixed_vertex_to_units (const fixed_vertex_t *f,
   u->z = CLUTTER_UNITS_FROM_FIXED (f->z);
 }
 
-/*
- * Utility functions for manipulating transformation matrix
- *
- * Matrix: 4x4 of ClutterFixed
- */
-#define M(m,row,col)  (m)[(col) * 4 + (row)]
-
 /* Transforms a vertex using the passed matrix; vertex is
  * an in-out parameter
  */
-static inline void
-mtx_transform (const ClutterFixed  m[],
-               fixed_vertex_t     *vertex)
+static void
+mtx_transform (const CoglMatrix *matrix,
+               fixed_vertex_t   *vertex)
 {
-  float _x, _y, _z, _w;
-
-  _x = vertex->x;
-  _y = vertex->y;
-  _z = vertex->z;
-  _w = vertex->w;
-
-  /* We care lot about precision here, so have to use MUL instead
-   * of FAST_MUL
-   */
-  vertex->x = CLUTTER_FIXED_MUL (M (m, 0, 0), _x)
-            + CLUTTER_FIXED_MUL (M (m, 0, 1), _y)
-            + CLUTTER_FIXED_MUL (M (m, 0, 2), _z)
-            + CLUTTER_FIXED_MUL (M (m, 0, 3), _w);
-
-  vertex->y = CLUTTER_FIXED_MUL (M (m, 1, 0), _x)
-            + CLUTTER_FIXED_MUL (M (m, 1, 1), _y)
-            + CLUTTER_FIXED_MUL (M (m, 1, 2), _z)
-            + CLUTTER_FIXED_MUL (M (m, 1, 3), _w);
-
-  vertex->z = CLUTTER_FIXED_MUL (M (m, 2, 0), _x)
-            + CLUTTER_FIXED_MUL (M (m, 2, 1), _y)
-            + CLUTTER_FIXED_MUL (M (m, 2, 2), _z)
-            + CLUTTER_FIXED_MUL (M (m, 2, 3), _w);
-
-  vertex->w = CLUTTER_FIXED_MUL (M (m, 3, 0), _x)
-            + CLUTTER_FIXED_MUL (M (m, 3, 1), _y)
-            + CLUTTER_FIXED_MUL (M (m, 3, 2), _z)
-            + CLUTTER_FIXED_MUL (M (m, 3, 3), _w);
-
-  /* Specially for Matthew: was going to put a comment here, but could not
-   * think of anything at all to say ;)
-   */
+  cogl_matrix_transform_point (matrix,
+                               &vertex->x,
+                               &vertex->y,
+                               &vertex->z,
+                               &vertex->w);
 }
 
-#undef M
-
 /* Help macros to scale from OpenGL <-1,1> coordinates system to our
  * X-window based <0,window-size> coordinates
  */
@@ -932,7 +895,7 @@ mtx_transform (const ClutterFixed  m[],
  * places the result into a fixed @vertex
  */
 static inline void
-fixed_vertex_transform (const ClutterFixed  matrix[],
+fixed_vertex_transform (const CoglMatrix   *matrix,
                         ClutterFixed        x,
                         ClutterFixed        y,
                         ClutterFixed        z,
@@ -955,7 +918,7 @@ fixed_vertex_transform (const ClutterFixed  matrix[],
  * transforms the result into ClutterUnits, filling @vertex_p
  */
 static inline void
-fixed_vertex_scale (const ClutterFixed    matrix[],
+fixed_vertex_scale (const CoglMatrix     *matrix,
                     const fixed_vertex_t *vertex,
                     const ClutterFixed    viewport[],
                     ClutterVertex        *vertex_p)
@@ -994,7 +957,7 @@ clutter_actor_transform_point_relative (ClutterActor *actor,
 					ClutterUnit  *z,
 					ClutterUnit  *w)
 {
-  ClutterFixed mtx[16];
+  CoglMatrix matrix;
   fixed_vertex_t vertex = { 0, };
 
   vertex.x = (x != NULL) ? CLUTTER_UNITS_TO_FIXED (*x) : 0;
@@ -1006,8 +969,8 @@ clutter_actor_transform_point_relative (ClutterActor *actor,
 
   _clutter_actor_apply_modelview_transform_recursive (actor, ancestor);
 
-  cogl_get_modelview_matrix (mtx);
-  mtx_transform (mtx, &vertex);
+  cogl_get_modelview_matrix (&matrix);
+  mtx_transform (&matrix, &vertex);
 
   cogl_pop_matrix();
 
@@ -1035,7 +998,7 @@ clutter_actor_transform_point (ClutterActor *actor,
 			       ClutterUnit  *z,
 			       ClutterUnit  *w)
 {
-  ClutterFixed mtx[16];
+  CoglMatrix matrix;
   fixed_vertex_t vertex = { 0, };
 
   vertex.x = (x != NULL) ? CLUTTER_UNITS_TO_FIXED (*x) : 0;
@@ -1047,8 +1010,8 @@ clutter_actor_transform_point (ClutterActor *actor,
 
   _clutter_actor_apply_modelview_transform_recursive (actor, NULL);
 
-  cogl_get_modelview_matrix (mtx);
-  mtx_transform (mtx, &vertex);
+  cogl_get_modelview_matrix (&matrix);
+  mtx_transform (&matrix, &vertex);
 
   cogl_pop_matrix();
 
@@ -1139,7 +1102,7 @@ clutter_actor_apply_transform_to_point (ClutterActor        *self,
                                         ClutterVertex       *vertex)
 {
   ClutterUnit x, y, z, w;
-  ClutterFixed mtx_p[16];
+  CoglMatrix matrix_p;
   ClutterFixed v[4];
   fixed_vertex_t tmp = { 0, };
 
@@ -1160,11 +1123,11 @@ clutter_actor_apply_transform_to_point (ClutterActor        *self,
   tmp.z = CLUTTER_UNITS_TO_FIXED (z);
   tmp.w = CLUTTER_UNITS_TO_FIXED (w);
 
-  cogl_get_projection_matrix (mtx_p);
+  cogl_get_projection_matrix (&matrix_p);
   cogl_get_viewport (v);
 
   /* Now, transform it again with the projection matrix */
-  mtx_transform (mtx_p, &tmp);
+  mtx_transform (&matrix_p, &tmp);
 
   /* Finaly translate from OpenGL coords to window coords */
   vertex->x =
@@ -1185,7 +1148,7 @@ clutter_actor_transform_vertices_relative (ClutterActor   *self,
                                            fixed_vertex_t  vertices[])
 {
   ClutterActorPrivate *priv = self->priv;
-  ClutterFixed mtx[16];
+  CoglMatrix mtx;
   ClutterFixed width, height;
 
   width  = CLUTTER_UNITS_TO_FIXED (priv->allocation.x2 - priv->allocation.x1);
@@ -1195,12 +1158,12 @@ clutter_actor_transform_vertices_relative (ClutterActor   *self,
 
   _clutter_actor_apply_modelview_transform_recursive (self, ancestor);
 
-  cogl_get_modelview_matrix (mtx);
+  cogl_get_modelview_matrix (&mtx);
 
-  fixed_vertex_transform (mtx, 0,     0,      0, 1.0, &vertices[0]);
-  fixed_vertex_transform (mtx, width, 0,      0, 1.0, &vertices[1]);
-  fixed_vertex_transform (mtx, 0,     height, 0, 1.0, &vertices[2]);
-  fixed_vertex_transform (mtx, width, height, 0, 1.0, &vertices[3]);
+  fixed_vertex_transform (&mtx, 0,     0,      0, 1.0, &vertices[0]);
+  fixed_vertex_transform (&mtx, width, 0,      0, 1.0, &vertices[1]);
+  fixed_vertex_transform (&mtx, 0,     height, 0, 1.0, &vertices[2]);
+  fixed_vertex_transform (&mtx, width, height, 0, 1.0, &vertices[3]);
 
   cogl_pop_matrix();
 }
@@ -1216,8 +1179,8 @@ clutter_actor_transform_and_project_box (ClutterActor          *self,
 					 ClutterVertex          verts[4])
 {
   ClutterActor *stage;
-  ClutterFixed mtx[16];
-  ClutterFixed mtx_p[16];
+  CoglMatrix mtx;
+  CoglMatrix mtx_p;
   ClutterFixed v[4];
   ClutterFixed width, height;
   fixed_vertex_t vertices[4];
@@ -1247,22 +1210,22 @@ clutter_actor_transform_and_project_box (ClutterActor          *self,
 
   _clutter_actor_apply_modelview_transform_recursive (self, NULL);
 
-  cogl_get_modelview_matrix (mtx);
+  cogl_get_modelview_matrix (&mtx);
 
-  fixed_vertex_transform (mtx, 0,     0,      0, 1.0, &vertices[0]);
-  fixed_vertex_transform (mtx, width, 0,      0, 1.0, &vertices[1]);
-  fixed_vertex_transform (mtx, 0,     height, 0, 1.0, &vertices[2]);
-  fixed_vertex_transform (mtx, width, height, 0, 1.0, &vertices[3]);
+  fixed_vertex_transform (&mtx, 0,     0,      0, 1.0, &vertices[0]);
+  fixed_vertex_transform (&mtx, width, 0,      0, 1.0, &vertices[1]);
+  fixed_vertex_transform (&mtx, 0,     height, 0, 1.0, &vertices[2]);
+  fixed_vertex_transform (&mtx, width, height, 0, 1.0, &vertices[3]);
 
   cogl_pop_matrix();
 
-  cogl_get_projection_matrix (mtx_p);
+  cogl_get_projection_matrix (&mtx_p);
   cogl_get_viewport (v);
 
-  fixed_vertex_scale (mtx_p, &vertices[0], v, &verts[0]);
-  fixed_vertex_scale (mtx_p, &vertices[1], v, &verts[1]);
-  fixed_vertex_scale (mtx_p, &vertices[2], v, &verts[2]);
-  fixed_vertex_scale (mtx_p, &vertices[3], v, &verts[3]);
+  fixed_vertex_scale (&mtx_p, &vertices[0], v, &verts[0]);
+  fixed_vertex_scale (&mtx_p, &vertices[1], v, &verts[1]);
+  fixed_vertex_scale (&mtx_p, &vertices[2], v, &verts[2]);
+  fixed_vertex_scale (&mtx_p, &vertices[3], v, &verts[3]);
 }
 
 /**
@@ -4510,7 +4473,7 @@ clutter_actor_get_transformed_sizeu (ClutterActor *self,
 
       box.x2 = box.x1 + natural_width;
       box.y2 = box.y1 + natural_height;
-      
+
       clutter_actor_transform_and_project_box (self, &box, v);
     }
   else
@@ -7997,7 +7960,7 @@ clutter_actor_allocate_preferred_size (ClutterActor *self,
   ClutterActorBox actor_box;
 
   g_return_if_fail (CLUTTER_IS_ACTOR (self));
-  
+
   actor_x = clutter_actor_get_xu (self);
   actor_y = clutter_actor_get_yu (self);
 
@@ -8005,7 +7968,7 @@ clutter_actor_allocate_preferred_size (ClutterActor *self,
                                     NULL, NULL,
                                     &natural_width,
                                     &natural_height);
-  
+
   actor_box.x1 = actor_x;
   actor_box.y1 = actor_y;
   actor_box.x2 = actor_box.x1 + natural_width;
diff --git a/clutter/cogl/cogl-matrix.h b/clutter/cogl/cogl-matrix.h
index 1d5942f..95ec92f 100644
--- a/clutter/cogl/cogl-matrix.h
+++ b/clutter/cogl/cogl-matrix.h
@@ -140,6 +140,42 @@ void cogl_matrix_scale (CoglMatrix *matrix,
 			float sy,
 			float sz);
 
+/**
+ * cogl_matrix_transform_point:
+ * @matrix: A 4x4 transformation matrix
+ * @x: The X component of your points position [in:out]
+ * @y: The Y component of your points position [in:out]
+ * @z: The Z component of your points position [in:out]
+ * @w: The W component of your points position [in:out]
+ *
+ * This transforms a point whos position is given and returned
+ * as four float components.
+ */
+void
+cogl_matrix_transform_point (const CoglMatrix *matrix,
+                             float *x,
+                             float *y,
+                             float *z,
+                             float *w);
+
+/**
+ * cogl_matrix_init_from_gl_matrix:
+ * @matrix: A 4x4 transformation matrix
+ * @gl_matrix: A linear array of 16 Glfloats (column-major)
+ *
+ * This initialises @matrix with the contents of @gl_matrix
+ */
+void cogl_matrix_init_from_gl_matrix (CoglMatrix *matrix, const float *gl_matrix);
+
+/**
+ * cogl_matrix_get_gl_matrix:
+ * @matrix: A 4x4 transformation matrix
+ *
+ * This casts a CoglMatrix to a GLfloat array which can be directly passed to
+ * OpenGL.
+ */
+const float *cogl_matrix_get_gl_matrix (const CoglMatrix *matrix);
+
 G_END_DECLS
 
 #endif /* __COGL_MATRIX_H */
diff --git a/clutter/cogl/cogl.h.in b/clutter/cogl/cogl.h.in
index 5aab2d9..06c32a5 100644
--- a/clutter/cogl/cogl.h.in
+++ b/clutter/cogl/cogl.h.in
@@ -268,21 +268,19 @@ void            cogl_rotate                   (float                angle,
 
 /**
  * cogl_get_modelview_matrix:
- * @m: pointer to a 4x4 array of #float<!-- -->s to receive the matrix
+ * @matrix: pointer to a CoglMatrix to recieve the matrix
  *
- * Stores the current model-view matrix in @m. The matrix is in
- * column-major order.
+ * Stores the current model-view matrix in @matrix.
  */
-void            cogl_get_modelview_matrix     (float        m[16]);
+void            cogl_get_modelview_matrix     (CoglMatrix *matrix);
 
 /**
  * cogl_get_projection_matrix:
- * @m: pointer to a 4x4 array of #float<!-- -->s to receive the matrix
+ * @matrix: pointer to a CoglMatrix to recieve the matrix
  *
- * Stores the current projection matrix in @m. The matrix is in
- * column-major order.
+ * Stores the current projection matrix in @matrix.
  */
-void            cogl_get_projection_matrix    (float        m[16]);
+void            cogl_get_projection_matrix    (CoglMatrix *matrix);
 
 /**
  * cogl_get_viewport:
diff --git a/clutter/cogl/common/cogl-clip-stack.c b/clutter/cogl/common/cogl-clip-stack.c
index 2330920..b80da0e 100644
--- a/clutter/cogl/common/cogl-clip-stack.c
+++ b/clutter/cogl/common/cogl-clip-stack.c
@@ -52,7 +52,7 @@ void _cogl_add_path_to_stencil_buffer (floatVec2 nodes_min,
 void _cogl_enable_clip_planes (void);
 void _cogl_disable_clip_planes (void);
 void _cogl_disable_stencil_buffer (void);
-void _cogl_set_matrix (const float *matrix);
+void _cogl_set_matrix (const CoglMatrix *matrix);
 
 typedef struct _CoglClipStack CoglClipStack;
 
@@ -81,7 +81,7 @@ struct _CoglClipStackEntryRect
   float                  height;
 
   /* The matrix that was current when the clip was set */
-  float                  matrix[16];
+  CoglMatrix             matrix;
 };
 
 struct _CoglClipStackEntryPath
@@ -89,7 +89,7 @@ struct _CoglClipStackEntryPath
   CoglClipStackEntryType     type;
 
   /* The matrix that was current when the clip was set */
-  float                  matrix[16];
+  CoglMatrix                 matrix;
 
   floatVec2              path_nodes_min;
   floatVec2              path_nodes_max;
@@ -120,7 +120,7 @@ cogl_clip_push (float x_offset,
   entry->width = width;
   entry->height = height;
 
-  cogl_get_modelview_matrix (entry->matrix);
+  cogl_get_modelview_matrix (&entry->matrix);
 
   /* Store it in the stack */
   stack->stack_top = g_list_prepend (stack->stack_top, entry);
@@ -148,7 +148,7 @@ cogl_clip_push_from_path_preserve (void)
   memcpy (entry->path, ctx->path_nodes->data,
           sizeof (CoglPathNode) * ctx->path_nodes->len);
 
-  cogl_get_modelview_matrix (entry->matrix);
+  cogl_get_modelview_matrix (&entry->matrix);
 
   /* Store it in the stack */
   stack->stack_top = g_list_prepend (stack->stack_top, entry);
@@ -226,7 +226,7 @@ _cogl_clip_stack_rebuild (void)
           CoglClipStackEntryPath *path = (CoglClipStackEntryPath *) entry;
 
           cogl_push_matrix ();
-          _cogl_set_matrix (path->matrix);
+          _cogl_set_matrix (&path->matrix);
 
           _cogl_add_path_to_stencil_buffer (path->path_nodes_min,
                                             path->path_nodes_max,
@@ -246,7 +246,7 @@ _cogl_clip_stack_rebuild (void)
           CoglClipStackEntryRect *rect = (CoglClipStackEntryRect *) entry;
 
           cogl_push_matrix ();
-          _cogl_set_matrix (rect->matrix);
+          _cogl_set_matrix (&rect->matrix);
 
           /* If this is the first entry and we support clip planes then use
              that instead */
diff --git a/clutter/cogl/common/cogl-matrix.c b/clutter/cogl/common/cogl-matrix.c
index 4d7ae6f..26b6b92 100644
--- a/clutter/cogl/common/cogl-matrix.c
+++ b/clutter/cogl/common/cogl-matrix.c
@@ -2,6 +2,7 @@
 
 #include <glib.h>
 #include <math.h>
+#include <string.h>
 
 void
 cogl_matrix_init_identity (CoglMatrix *matrix)
@@ -42,7 +43,7 @@ cogl_matrix_multiply (CoglMatrix *result,
   r.wy = a->wx * b->xy + a->wy * b->yy + a->wz * b->zy + a->ww * b->wy;
   r.wz = a->wx * b->xz + a->wy * b->yz + a->wz * b->zz + a->ww * b->wz;
   r.ww = a->wx * b->xw + a->wy * b->yw + a->wz * b->zw + a->ww * b->ww;
-  
+
   /* The idea was that having this unrolled; it might be easier for the
    * compiler to vectorize, but that's probably not true. Mesa does it
    * using a single for (i=0; i<4; i++) approach, may that's better...
@@ -51,19 +52,6 @@ cogl_matrix_multiply (CoglMatrix *result,
   *result = r;
 }
 
-/**
- * cogl_3dmatrix_rotate:
- * @matrix: A 3D Affine transformation matrix
- * @angle: The angle in degrees you want to rotate by
- * @x: The X component of your rotation vector
- * @y: The Y component of your rotation vector
- * @z: The Z component of your rotation vector
- *
- * The matrix is multiplied with a rotation matrix representing a rotation
- * of angle degress around the vector (x,y,z)
- *
- * Since: 1.0
- */
 void
 cogl_matrix_rotate (CoglMatrix *matrix,
 		    float angle,
@@ -76,7 +64,7 @@ cogl_matrix_rotate (CoglMatrix *matrix,
   angle *= G_PI / 180.0f;
   float c = cosf (angle);
   float s = sinf (angle);
-  
+
   rotation.xx = x * x * (1.0f - c) + c;
   rotation.yx = y * x * (1.0f - c) + z * s;
   rotation.zx = x * z * (1.0f - c) - y * s;
@@ -96,7 +84,7 @@ cogl_matrix_rotate (CoglMatrix *matrix,
   rotation.yw = 0.0f;
   rotation.zw = 0.0f;
   rotation.ww = 1.0f;
-  
+
   cogl_matrix_multiply (&result, matrix, &rotation);
   *matrix = result;
 }
@@ -137,4 +125,30 @@ cogl_matrix_invert (CoglMatrix *matrix)
 }
 #endif
 
+void
+cogl_matrix_transform_point (const CoglMatrix *matrix,
+                             float *x,
+                             float *y,
+                             float *z,
+                             float *w)
+{
+  float _x = *x, _y = *y, _z = *z, _w = *w;
+
+  *x = matrix->xx * _x + matrix->xy * _y + matrix->xz * _z + matrix->xw * _w;
+  *y = matrix->yx * _x + matrix->yy * _y + matrix->yz * _z + matrix->yw * _w;
+  *z = matrix->zx * _x + matrix->zy * _y + matrix->zz * _z + matrix->zw * _w;
+  *w = matrix->wx * _x + matrix->wy * _y + matrix->wz * _z + matrix->ww * _w;
+}
+
+void
+cogl_matrix_init_from_gl_matrix (CoglMatrix *matrix, const float *gl_matrix)
+{
+  memcpy (matrix, gl_matrix, sizeof (float) * 16);
+}
+
+const float *
+cogl_matrix_get_gl_matrix (const CoglMatrix *matrix)
+{
+  return (float *)matrix;
+}
 
diff --git a/clutter/cogl/gl/cogl.c b/clutter/cogl/gl/cogl.c
index 27bf0c8..8073ad1 100644
--- a/clutter/cogl/gl/cogl.c
+++ b/clutter/cogl/gl/cogl.c
@@ -530,10 +530,11 @@ _cogl_add_stencil_clip (float x_offset,
 }
 
 void
-_cogl_set_matrix (const float *matrix)
+_cogl_set_matrix (const CoglMatrix *matrix)
 {
-  GE( glLoadIdentity () );
-  GE( glMultMatrixf (matrix) );
+  const GLfloat *gl_matrix = cogl_matrix_get_gl_matrix (matrix);
+
+  GE (glLoadMatrixf (gl_matrix));
 }
 
 void
@@ -678,7 +679,7 @@ cogl_setup_viewport (guint width,
 		     float z_far)
 {
   float z_camera;
-  float projection_matrix[16];
+  CoglMatrix projection_matrix;
 
   GE( glViewport (0, 0, width, height) );
 
@@ -727,8 +728,8 @@ cogl_setup_viewport (guint width,
    * doesn't make sense.
    */
 
-  cogl_get_projection_matrix (projection_matrix);
-  z_camera = 0.5 * projection_matrix[0];
+  cogl_get_projection_matrix (&projection_matrix);
+  z_camera = 0.5 * projection_matrix.xx;
 
   GE( glLoadIdentity () );
 
@@ -1122,15 +1123,25 @@ cogl_features_available (CoglFeatureFlags features)
 }
 
 void
-cogl_get_modelview_matrix (float m[16])
+cogl_get_modelview_matrix (CoglMatrix *matrix)
 {
+  float m[16];
   glGetFloatv (GL_MODELVIEW_MATRIX, m);
+  /* Since it's internal to Cogl and CoglMatrix doesn't currently have
+   * any flag members, we could avoid this extra copy if it really
+   * bothers anyone */
+  cogl_matrix_init_from_gl_matrix (matrix, m);
 }
 
 void
-cogl_get_projection_matrix (float m[16])
+cogl_get_projection_matrix (CoglMatrix *matrix)
 {
+  float m[16];
   glGetFloatv (GL_PROJECTION_MATRIX, m);
+  /* Since it's internal to Cogl and CoglMatrix doesn't currently have
+   * any flag members, we could avoid this extra copy if it really
+   * bothers anyone */
+  cogl_matrix_init_from_gl_matrix (matrix, m);
 }
 
 void
diff --git a/clutter/cogl/gles/cogl.c b/clutter/cogl/gles/cogl.c
index 7ac6025..f096a37 100644
--- a/clutter/cogl/gles/cogl.c
+++ b/clutter/cogl/gles/cogl.c
@@ -453,10 +453,11 @@ _cogl_add_stencil_clip (float x_offset,
 }
 
 void
-_cogl_set_matrix (const float *matrix)
+_cogl_set_matrix (const CoglMatrix *matrix)
 {
-  GE( glLoadIdentity () );
-  GE( glMultMatrixf (matrix) );
+  const GLfloat *gl_matrix = cogl_matrix_get_gl_matrix (matrix);
+
+  GE (glLoadMatrixf (gl_matrix));
 }
 
 void
@@ -601,7 +602,7 @@ cogl_setup_viewport (guint width,
 		     float z_far)
 {
   float z_camera;
-  float projection_matrix[16];
+  CoglMatrix projection_matrix;
 
   GE( glViewport (0, 0, width, height) );
 
@@ -617,8 +618,8 @@ cogl_setup_viewport (guint width,
    * See comments in ../gl/cogl.c
    */
 
-  cogl_get_projection_matrix (projection_matrix);
-  z_camera = 0.5 * projection_matrix[0];
+  cogl_get_projection_matrix (&projection_matrix);
+  z_camera = 0.5 * projection_matrix.xx;
 
   GE( glLoadIdentity () );
 
@@ -679,15 +680,25 @@ cogl_features_available (CoglFeatureFlags features)
 }
 
 void
-cogl_get_modelview_matrix (float m[16])
+cogl_get_modelview_matrix (CoglMatrix *matrix)
 {
+  float m[16];
   glGetFloatv (GL_MODELVIEW_MATRIX, m);
+  /* Since it's internal to Cogl and CoglMatrix doesn't currently have
+   * any flag members, we could avoid this extra copy if it really
+   * bothers anyone */
+  cogl_matrix_init_from_gl_matrix (matrix, m);
 }
 
 void
-cogl_get_projection_matrix (float m[16])
+cogl_get_projection_matrix (CoglMatrix *matrix)
 {
+  float m[16];
   glGetFloatv (GL_PROJECTION_MATRIX, m);
+  /* Since it's internal to Cogl and CoglMatrix doesn't currently have
+   * any flag members, we could avoid this extra copy if it really
+   * bothers anyone */
+  cogl_matrix_init_from_gl_matrix (matrix, m);
 }
 
 void