r300g: move index buffer translate functions to their new home

1 files changed, 137 insertions, 3 deletions

diff --git a/src/gallium/drivers/r300/r300_render_translate.c b/src/gallium/drivers/r300/r300_render_translate.c
index b03582aac3..ea3c9668f7 100644
--- a/src/gallium/drivers/r300/r300_render_translate.c
+++ b/src/gallium/drivers/r300/r300_render_translate.c
@@ -21,9 +21,10 @@
  * USE OR OTHER DEALINGS IN THE SOFTWARE. */
 
 /**
- * The functions below translate vertex buffers to the layout compatible
- * with the hardware, so that all vertex fetches are be DWORD-aligned and all
- * used vertex formats are supported.
+ * The functions below translate vertex and index buffers to the layout
+ * compatible with the hardware, so that all vertex and index fetches are
+ * DWORD-aligned and all used vertex and index formats are supported.
+ * For indices, an optional index offset is added to each index.
  */
 
 #include "r300_context.h"
@@ -163,3 +164,136 @@ void r300_end_vertex_translate(struct r300_context *r300)
     pipe_resource_reference(&r300->vertex_buffer[r300->tran.vb_slot].buffer,
                             NULL);
 }
+
+static void r300_shorten_ubyte_elts(struct r300_context* r300,
+                                    struct pipe_resource** elts,
+                                    int index_bias,
+                                    unsigned start,
+                                    unsigned count)
+{
+    struct pipe_context* context = &r300->context;
+    struct pipe_screen* screen = r300->context.screen;
+    struct pipe_resource* new_elts;
+    unsigned char *in_map;
+    unsigned short *out_map;
+    struct pipe_transfer *src_transfer, *dst_transfer;
+    unsigned i;
+
+    new_elts = pipe_buffer_create(screen,
+                                  PIPE_BIND_INDEX_BUFFER,
+                                  2 * count);
+
+    in_map = pipe_buffer_map(context, *elts, PIPE_TRANSFER_READ, &src_transfer);
+    out_map = pipe_buffer_map(context, new_elts, PIPE_TRANSFER_WRITE, &dst_transfer);
+
+    in_map += start;
+
+    for (i = 0; i < count; i++) {
+        *out_map = (unsigned short)(*in_map + index_bias);
+        in_map++;
+        out_map++;
+    }
+
+    pipe_buffer_unmap(context, *elts, src_transfer);
+    pipe_buffer_unmap(context, new_elts, dst_transfer);
+
+    *elts = new_elts;
+}
+
+static void r300_rebuild_ushort_elts(struct r300_context *r300,
+                                     struct pipe_resource **elts,
+                                     int index_bias,
+                                     unsigned start, unsigned count)
+{
+    struct pipe_context *context = &r300->context;
+    struct pipe_transfer *in_transfer = NULL;
+    struct pipe_transfer *out_transfer = NULL;
+    struct pipe_resource *new_elts;
+    unsigned short *in_map;
+    unsigned short *out_map;
+    unsigned i;
+
+    new_elts = pipe_buffer_create(context->screen,
+                                  PIPE_BIND_INDEX_BUFFER,
+                                  2 * count);
+
+    in_map = pipe_buffer_map(context, *elts,
+                             PIPE_TRANSFER_READ, &in_transfer);
+    out_map = pipe_buffer_map(context, new_elts,
+                              PIPE_TRANSFER_WRITE, &out_transfer);
+
+    in_map += start;
+    for (i = 0; i < count; i++) {
+        *out_map = (unsigned short)(*in_map + index_bias);
+        in_map++;
+        out_map++;
+    }
+
+    pipe_buffer_unmap(context, *elts, in_transfer);
+    pipe_buffer_unmap(context, new_elts, out_transfer);
+
+    *elts = new_elts;
+}
+
+static void r300_rebuild_uint_elts(struct r300_context *r300,
+                                   struct pipe_resource **elts,
+                                   int index_bias,
+                                   unsigned start, unsigned count)
+{
+    struct pipe_context *context = &r300->context;
+    struct pipe_transfer *in_transfer = NULL;
+    struct pipe_transfer *out_transfer = NULL;
+    struct pipe_resource *new_elts;
+    unsigned int *in_map;
+    unsigned int *out_map;
+    unsigned i;
+
+    new_elts = pipe_buffer_create(context->screen,
+                                  PIPE_BIND_INDEX_BUFFER,
+                                  2 * count);
+
+    in_map = pipe_buffer_map(context, *elts,
+                             PIPE_TRANSFER_READ, &in_transfer);
+    out_map = pipe_buffer_map(context, new_elts,
+                              PIPE_TRANSFER_WRITE, &out_transfer);
+
+    in_map += start;
+    for (i = 0; i < count; i++) {
+        *out_map = (unsigned int)(*in_map + index_bias);
+        in_map++;
+        out_map++;
+    }
+
+    pipe_buffer_unmap(context, *elts, in_transfer);
+    pipe_buffer_unmap(context, new_elts, out_transfer);
+
+    *elts = new_elts;
+}
+
+void r300_translate_index_buffer(struct r300_context *r300,
+                                 struct pipe_resource **index_buffer,
+                                 unsigned *index_size, unsigned index_offset,
+                                 unsigned *start, unsigned count)
+{
+    switch (*index_size) {
+        case 1:
+            r300_shorten_ubyte_elts(r300, index_buffer, index_offset, *start, count);
+            *index_size = 2;
+            *start = 0;
+            break;
+
+        case 2:
+            if (*start % 2 != 0 || index_offset) {
+                r300_rebuild_ushort_elts(r300, index_buffer, index_offset, *start, count);
+                *start = 0;
+            }
+            break;
+
+        case 4:
+            if (index_offset) {
+                r300_rebuild_uint_elts(r300, index_buffer, index_offset, *start, count);
+                *start = 0;
+            }
+            break;
+    }
+}