From 6c8c0714f67866c42e1d7b4e1e5da60f16647f77 Mon Sep 17 00:00:00 2001
From: Robert Bragg <robert@linux.intel.com>
Date: Fri, 19 Mar 2010 09:30:59 +0000
Subject: [PATCH] cogl: adds convenience cogl_multiply_matrix function

Quite often it's desirable to be able to multiply the current modelview
matrix by an arbitrary matrix. Currently though you have to first
explicitly call cogl_get_modelview_matrix to get the current modelview
into a temporary variable, then you need to multiply it with your matrix
using cogl_matrix_multiply and finally use cogl_set_modelview_matrix to
make the result be the new modelview. This new convenience function lets
more efficiently skip the first get and last set steps.
---
 cogl/cogl.c |  8 ++++++++
 cogl/cogl.h | 11 +++++++++++
 2 files changed, 19 insertions(+)

diff --git a/cogl/cogl.c b/cogl/cogl.c
index 106c229c9..9632ce529 100644
--- a/cogl/cogl.c
+++ b/cogl/cogl.c
@@ -937,6 +937,14 @@ cogl_rotate (float angle, float x, float y, float z)
   _cogl_matrix_stack_rotate (modelview_stack, angle, x, y, z);
 }
 
+void
+cogl_multiply_matrix (const CoglMatrix *matrix)
+{
+  CoglMatrixStack *modelview_stack =
+    _cogl_framebuffer_get_modelview_stack (_cogl_get_framebuffer ());
+  _cogl_matrix_stack_multiply (modelview_stack, matrix);
+}
+
 void
 cogl_perspective (float fov_y,
 		  float aspect,
diff --git a/cogl/cogl.h b/cogl/cogl.h
index 53ddec2de..b2e244736 100644
--- a/cogl/cogl.h
+++ b/cogl/cogl.h
@@ -347,6 +347,17 @@ cogl_rotate (float angle,
              float y,
              float z);
 
+/**
+ * cogl_multiply_matrix:
+ * @matrix: the matrix to multiply with the current model-view
+ *
+ * Multiplies the current model-view matrix by the given matrix.
+ *
+ * Since: 1.4
+ */
+void
+cogl_multiply_matrix (const CoglMatrix *matrix);
+
 /**
  * cogl_get_modelview_matrix:
  * @matrix: (out): return location for the model-view matrix