Mesa (master): vbo: add comments, const qualifiers

[Brian Paul]

Module: Mesa
Branch: master
Commit: 76084907fb720baf8894ca4c2d05b0e00dd7c12c
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=76084907fb720baf8894ca4c2d05b0e00dd7c12c

Author: Brian Paul <brianp at vmware.com>
Date:   Fri May  3 19:00:07 2013 -0600

vbo: add comments, const qualifiers

Reviewed-by: José Fonseca <jfonseca at vmware.com>

---

 src/mesa/vbo/vbo_save.h     |    8 ++++----
 src/mesa/vbo/vbo_save_api.c |   25 ++++++++++++++++++++-----
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/mesa/vbo/vbo_save.h b/src/mesa/vbo/vbo_save.h
index c1108ca..aa075bb 100644
--- a/src/mesa/vbo/vbo_save.h
+++ b/src/mesa/vbo/vbo_save.h
@@ -126,10 +126,10 @@ struct vbo_save_context {
    struct gl_client_array arrays[VBO_ATTRIB_MAX];
    const struct gl_client_array *inputs[VBO_ATTRIB_MAX];
 
-   GLubyte attrsz[VBO_ATTRIB_MAX];
-   GLenum attrtype[VBO_ATTRIB_MAX];
-   GLubyte active_sz[VBO_ATTRIB_MAX];
-   GLuint vertex_size;
+   GLubyte attrsz[VBO_ATTRIB_MAX];  /**< 1, 2, 3 or 4 */
+   GLenum attrtype[VBO_ATTRIB_MAX];  /**< GL_FLOAT, GL_INT, etc */
+   GLubyte active_sz[VBO_ATTRIB_MAX];  /**< 1, 2, 3 or 4 */
+   GLuint vertex_size;  /**< size in GLfloats */
 
    GLboolean out_of_memory;  /**< True if last VBO allocation failed */
 
diff --git a/src/mesa/vbo/vbo_save_api.c b/src/mesa/vbo/vbo_save_api.c
index dd13c49..26951bd 100644
--- a/src/mesa/vbo/vbo_save_api.c
+++ b/src/mesa/vbo/vbo_save_api.c
@@ -469,6 +469,8 @@ _save_compile_vertex_list(struct gl_context *ctx)
 
 
 /**
+ * This is called when we fill a vertex buffer before we hit a glEnd().
+ * We
  * TODO -- If no new vertices have been stored, don't bother saving it.
  */
 static void
@@ -577,7 +579,11 @@ _save_copy_from_current(struct gl_context *ctx)
 }
 
 
-/* Flush existing data, set new attrib size, replay copied vertices.
+/**
+ * Called when we increase the size of a vertex attribute.  For example,
+ * if we've seen one or more glTexCoord2f() calls and now we get a
+ * glTexCoord3f() call.
+ * Flush existing data, set new attrib size, replay copied vertices.
  */
 static void
 _save_upgrade_vertex(struct gl_context *ctx, GLuint attr, GLuint newsz)
@@ -634,7 +640,7 @@ _save_upgrade_vertex(struct gl_context *ctx, GLuint attr, GLuint newsz)
     * and will need fixup at runtime.
     */
    if (save->copied.nr) {
-      GLfloat *data = save->copied.buffer;
+      const GLfloat *data = save->copied.buffer;
       GLfloat *dest = save->buffer;
       GLuint j;
 
@@ -676,6 +682,11 @@ _save_upgrade_vertex(struct gl_context *ctx, GLuint attr, GLuint newsz)
 }
 
 
+/**
+ * This is called when the size of a vertex attribute changes.
+ * For example, after seeing one or more glTexCoord2f() calls we
+ * get a glTexCoord4f() or glTexCoord1f() call.
+ */
 static void
 save_fixup_vertex(struct gl_context *ctx, GLuint attr, GLuint sz)
 {
@@ -702,6 +713,11 @@ save_fixup_vertex(struct gl_context *ctx, GLuint attr, GLuint sz)
 }
 
 
+/**
+ * Reset the current size of all vertex attributes to the default
+ * value of 0.  This signals that we haven't yet seen any per-vertex
+ * commands such as glNormal3f() or glTexCoord2f().
+ */
 static void
 _save_reset_vertex(struct gl_context *ctx)
 {
@@ -933,8 +949,7 @@ GLboolean
 vbo_save_NotifyBegin(struct gl_context *ctx, GLenum mode)
 {
    struct vbo_save_context *save = &vbo_context(ctx)->save;
-
-   GLuint i = save->prim_count++;
+   const GLuint i = save->prim_count++;
 
    assert(i < save->prim_max);
    save->prim[i].mode = mode & VBO_SAVE_PRIM_MODE_MASK;
@@ -971,7 +986,7 @@ _save_End(void)
 {
    GET_CURRENT_CONTEXT(ctx);
    struct vbo_save_context *save = &vbo_context(ctx)->save;
-   GLint i = save->prim_count - 1;
+   const GLint i = save->prim_count - 1;
 
    ctx->Driver.CurrentSavePrimitive = PRIM_OUTSIDE_BEGIN_END;
    save->prim[i].end = 1;