mesa: added _mesa_format_row_stride()

2 files changed, 25 insertions, 1 deletions

diff --git a/src/mesa/main/formats.c b/src/mesa/main/formats.c
index 82843a3291..ebe59f8960 100644
--- a/src/mesa/main/formats.c
+++ b/src/mesa/main/formats.c
@@ -602,12 +602,13 @@ _mesa_format_image_size(gl_format format, GLsizei width,
                         GLsizei height, GLsizei depth)
 {
    const struct gl_format_info *info = _mesa_get_format_info(format);
+   /* Strictly speaking, a conditional isn't needed here */
    if (info->BlockWidth > 1 || info->BlockHeight > 1) {
       /* compressed format */
       const GLuint bw = info->BlockWidth, bh = info->BlockHeight;
       const GLuint wblocks = (width + bw - 1) / bw;
       const GLuint hblocks = (height + bh - 1) / bh;
-      const GLuint sz  = wblocks * hblocks * info->BytesPerBlock;
+      const GLuint sz = wblocks * hblocks * info->BytesPerBlock;
       return sz;
    }
    else {
@@ -619,6 +620,25 @@ _mesa_format_image_size(gl_format format, GLsizei width,
 
 
 
+GLint
+_mesa_format_row_stride(gl_format format, GLsizei width)
+{
+   const struct gl_format_info *info = _mesa_get_format_info(format);
+   /* Strictly speaking, a conditional isn't needed here */
+   if (info->BlockWidth > 1 || info->BlockHeight > 1) {
+      /* compressed format */
+      const GLuint bw = info->BlockWidth;
+      const GLuint wblocks = (width + bw - 1) / bw;
+      const GLint stride = wblocks * info->BytesPerBlock;
+      return stride;
+   }
+   else {
+      const GLint stride = width * info->BytesPerBlock;
+      return stride;
+   }
+}
+
+
 
 /**
  * Do sanity checking of the format info table.
diff --git a/src/mesa/main/formats.h b/src/mesa/main/formats.h
index b91682809f..316ff1a8ec 100644
--- a/src/mesa/main/formats.h
+++ b/src/mesa/main/formats.h
@@ -206,6 +206,10 @@ extern GLuint
 _mesa_format_image_size(gl_format format, GLsizei width,
                         GLsizei height, GLsizei depth);
 
+extern GLint
+_mesa_format_row_stride(gl_format format, GLsizei width);
+
+
 extern void
 _mesa_test_formats(void);