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authorBrian Paul <brian.paul@tungstengraphics.com>2003-06-04 17:18:09 +0000
committerBrian Paul <brian.paul@tungstengraphics.com>2003-06-04 17:18:09 +0000
commitb9e1411660d80612ec9706c443eacb0f46caefad (patch)
treee6306dd1b3117d2426096b46c135da9dd8b75b4a
parent3c28d1e2a9d758583efd8e51c42992987e6be982 (diff)
comments regarding window sizing
-rw-r--r--src/mesa/main/buffers.c11
-rw-r--r--src/mesa/main/matrix.c15
2 files changed, 18 insertions, 8 deletions
diff --git a/src/mesa/main/buffers.c b/src/mesa/main/buffers.c
index 2232ed0606..92379a2335 100644
--- a/src/mesa/main/buffers.c
+++ b/src/mesa/main/buffers.c
@@ -371,11 +371,14 @@ _mesa_ReadBuffer( GLenum mode )
}
-/*
- * GL_MESA_resize_buffers extension
+/**
* When this function is called, we'll ask the window system how large
- * the current window is. If it's not what we expect, we'll have to
- * resize/reallocate the software accum/stencil/depth/alpha buffers.
+ * the current window is. If it's a new size, we'll call the driver's
+ * ResizeBuffers function. The driver will then resize its color buffers
+ * as needed, and maybe call the swrast's routine for reallocating
+ * swrast-managed depth/stencil/accum/etc buffers.
+ * \note This function may be called from within Mesa or called by the
+ * user directly (see the GL_MESA_resize_buffers extension).
*/
void
_mesa_ResizeBuffersMESA( void )
diff --git a/src/mesa/main/matrix.c b/src/mesa/main/matrix.c
index 83d2ff425e..244b04ca40 100644
--- a/src/mesa/main/matrix.c
+++ b/src/mesa/main/matrix.c
@@ -414,9 +414,13 @@ _mesa_Viewport( GLint x, GLint y, GLsizei width, GLsizei height )
}
-/*
- * Define a new viewport and reallocate auxillary buffers if the size of
- * the window (color buffer) has changed.
+/**
+ * Set new viewport parameters and update derived state (the _WindowMap
+ * matrix). Usually called from _mesa_Viewport().
+ * \note We also call _mesa_ResizeBuffersMESA() because this is a good
+ * time to check if the window has been resized. Many device drivers
+ * can't get direct notification from the window system of size changes
+ * so this is an ad-hoc solution to that problem.
*/
void
_mesa_set_viewport( GLcontext *ctx, GLint x, GLint y,
@@ -458,7 +462,10 @@ _mesa_set_viewport( GLcontext *ctx, GLint x, GLint y,
ctx->NewState |= _NEW_VIEWPORT;
/* Check if window/buffer has been resized and if so, reallocate the
- * ancillary buffers.
+ * ancillary buffers. This is an ad-hoc solution to detecting window
+ * size changes. 99% of all GL apps call glViewport when a window is
+ * resized so this is a good time to check for new window dims and
+ * reallocate color buffers and ancilliary buffers.
*/
_mesa_ResizeBuffersMESA();