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-rw-r--r--src/mesa/main/image.c42
1 files changed, 41 insertions, 1 deletions
diff --git a/src/mesa/main/image.c b/src/mesa/main/image.c
index 0a117a967b..ee44e37295 100644
--- a/src/mesa/main/image.c
+++ b/src/mesa/main/image.c
@@ -2,7 +2,7 @@
* Mesa 3-D graphics library
* Version: 6.5
*
- * Copyright (C) 1999-2005 Brian Paul All Rights Reserved.
+ * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
@@ -4312,3 +4312,43 @@ _mesa_clip_readpixels(const GLcontext *ctx,
return GL_TRUE;
}
+
+/**
+ * Clip the rectangle defined by (x, y, width, height) against the bounds
+ * specified by [xmin, xmax) and [ymin, ymax).
+ * \return GL_FALSE if rect is totally clipped, GL_TRUE otherwise.
+ */
+GLboolean
+_mesa_clip_to_region(GLint xmin, GLint ymin,
+ GLint xmax, GLint ymax,
+ GLint *x, GLint *y,
+ GLsizei *width, GLsizei *height )
+{
+ /* left clipping */
+ if (*x < xmin) {
+ *width -= (xmin - *x);
+ *x = xmin;
+ }
+
+ /* right clipping */
+ if (*x + *width > xmax)
+ *width -= (*x + *width - xmax - 1);
+
+ if (*width <= 0)
+ return GL_FALSE;
+
+ /* bottom (or top) clipping */
+ if (*y < ymin) {
+ *height -= (ymin - *y);
+ *y = ymin;
+ }
+
+ /* top (or bottom) clipping */
+ if (*y + *height > ymax)
+ *height -= (*y + *height - ymax - 1);
+
+ if (*height <= 0)
+ return GL_FALSE;
+
+ return GL_TRUE;
+}