glthread: execute small glBitmap asynchronously

Compute the bitmap size and copy the bitmap into the batch.

Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27490>

src/mapi/glapi/gen/gl_API.xml

@@ -1161,8 +1161,7 @@
         <glx rop="4"/>
     </function>
 
-    <function name="Bitmap" deprecated="3.1" exec="dlist"
-              marshal="async" marshal_sync="_mesa_glthread_has_no_unpack_buffer(ctx)">
+    <function name="Bitmap" deprecated="3.1" exec="dlist" marshal="custom">
         <param name="width" type="GLsizei"/>
         <param name="height" type="GLsizei"/>
         <param name="xorig" type="GLfloat"/>

src/mesa/main/glthread_pixels.c

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "main/glthread_marshal.h"
+#include "main/dispatch.h"
+#include "main/image.h"
+
+#define MAX_BITMAP_BYTE_SIZE     4096
+
+struct marshal_cmd_Bitmap
+{
+   struct marshal_cmd_base cmd_base;
+   uint16_t num_slots;
+   GLsizei width;
+   GLsizei height;
+   GLfloat xorig;
+   GLfloat yorig;
+   GLfloat xmove;
+   GLfloat ymove;
+   GLubyte *bitmap;
+};
+
+uint32_t
+_mesa_unmarshal_Bitmap(struct gl_context *ctx,
+                       const struct marshal_cmd_Bitmap *restrict cmd)
+{
+   CALL_Bitmap(ctx->Dispatch.Current,
+               (cmd->width, cmd->height, cmd->xorig, cmd->yorig, cmd->xmove,
+                cmd->ymove, cmd->bitmap));
+   return cmd->num_slots;
+}
+
+void GLAPIENTRY
+_mesa_marshal_Bitmap(GLsizei width, GLsizei height, GLfloat xorig,
+                     GLfloat yorig, GLfloat xmove, GLfloat ymove,
+                     const GLubyte *bitmap)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   int cmd_size = sizeof(struct marshal_cmd_Bitmap);
+
+   /* If not building a display list... */
+   if (!ctx->GLThread.ListMode) {
+      /* PBO path or bitmap == NULL (which means xmove/ymove only move the raster
+       * pos.
+       */
+      if (!bitmap || !_mesa_glthread_has_no_unpack_buffer(ctx)) {
+         struct marshal_cmd_Bitmap *cmd =
+            _mesa_glthread_allocate_command(ctx, DISPATCH_CMD_Bitmap,
+                                            cmd_size);
+         cmd->num_slots = align(cmd_size, 8) / 8;
+         cmd->width = width;
+         cmd->height = height;
+         cmd->xorig = xorig;
+         cmd->yorig = yorig;
+         cmd->xmove = xmove;
+         cmd->ymove = ymove;
+         cmd->bitmap = (GLubyte *)bitmap;
+         return;
+      }
+
+      size_t bitmap_size =
+         (size_t)_mesa_image_row_stride(&ctx->GLThread.Unpack, width,
+                                        GL_COLOR_INDEX, GL_BITMAP) * height;
+
+      /* If the bitmap is small enough, copy it into the batch. */
+      if (bitmap_size <= MAX_BITMAP_BYTE_SIZE) {
+         struct marshal_cmd_Bitmap *cmd =
+            _mesa_glthread_allocate_command(ctx, DISPATCH_CMD_Bitmap,
+                                            cmd_size + bitmap_size);
+         cmd->num_slots = align(cmd_size + bitmap_size, 8) / 8;
+         cmd->width = width;
+         cmd->height = height;
+         cmd->xorig = xorig;
+         cmd->yorig = yorig;
+         cmd->xmove = xmove;
+         cmd->ymove = ymove;
+         cmd->bitmap = (GLubyte *)(cmd + 1);
+         memcpy(cmd->bitmap, bitmap, bitmap_size);
+         return;
+      }
+   }
+
+   _mesa_glthread_finish_before(ctx, "Bitmap");
+   CALL_Bitmap(ctx->Dispatch.Current,
+               (width, height, xorig, yorig, xmove, ymove, bitmap));
+}

src/mesa/meson.build

@@ -123,6 +123,7 @@ files_libmesa = files(
   'main/glthread_get.c',
   'main/glthread_list.c',
   'main/glthread_marshal.h',
+  'main/glthread_pixels.c',
   'main/glthread_shaderobj.c',
   'main/glthread_varray.c',
   'main/hash.c',