From 9939f20a499b4201ab4ebdc0d0e8dde01f78637a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Ol=C5=A1=C3=A1k?= <marek.olsak@amd.com>
Date: Wed, 31 Jan 2024 01:18:32 -0500
Subject: [PATCH] glthread: execute small glDrawPixels asynchronously

Compute the image size and copy the image 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   |  3 +-
 src/mesa/main/glthread_pixels.c | 73 +++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/src/mapi/glapi/gen/gl_API.xml b/src/mapi/glapi/gen/gl_API.xml
index 01f1598f851..d12d33364ac 100644
--- a/src/mapi/glapi/gen/gl_API.xml
+++ b/src/mapi/glapi/gen/gl_API.xml
@@ -2682,8 +2682,7 @@
         <glx sop="111"/>
     </function>
 
-    <function name="DrawPixels" deprecated="3.1" exec="dlist"
-              marshal="async" marshal_sync="_mesa_glthread_has_no_unpack_buffer(ctx)">
+    <function name="DrawPixels" deprecated="3.1" exec="dlist" marshal="custom">
         <param name="width" type="GLsizei"/>
         <param name="height" type="GLsizei"/>
         <param name="format" type="GLenum"/>
diff --git a/src/mesa/main/glthread_pixels.c b/src/mesa/main/glthread_pixels.c
index c8fed4bb7db..bceef8081dd 100644
--- a/src/mesa/main/glthread_pixels.c
+++ b/src/mesa/main/glthread_pixels.c
@@ -9,6 +9,7 @@
 #include "main/image.h"
 
 #define MAX_BITMAP_BYTE_SIZE     4096
+#define MAX_DRAWPIX_BYTE_SIZE    4096
 
 struct marshal_cmd_Bitmap
 {
@@ -87,3 +88,75 @@ _mesa_marshal_Bitmap(GLsizei width, GLsizei height, GLfloat xorig,
    CALL_Bitmap(ctx->Dispatch.Current,
                (width, height, xorig, yorig, xmove, ymove, bitmap));
 }
+
+struct marshal_cmd_DrawPixels
+{
+   struct marshal_cmd_base cmd_base;
+   uint16_t num_slots;
+   GLenum16 format;
+   GLenum16 type;
+   GLsizei width;
+   GLsizei height;
+   GLvoid *pixels;
+};
+
+uint32_t
+_mesa_unmarshal_DrawPixels(struct gl_context *ctx,
+                           const struct marshal_cmd_DrawPixels *restrict cmd)
+{
+   CALL_DrawPixels(ctx->Dispatch.Current,
+                   (cmd->width, cmd->height, cmd->format, cmd->type,
+                    cmd->pixels));
+   return cmd->num_slots;
+}
+
+void GLAPIENTRY
+_mesa_marshal_DrawPixels(GLsizei width, GLsizei height, GLenum format,
+                         GLenum type, const GLvoid *pixels)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   int cmd_size = sizeof(struct marshal_cmd_DrawPixels);
+
+   /* If not building a display list... */
+   if (!ctx->GLThread.ListMode) {
+      /* PBO */
+      if (!_mesa_glthread_has_no_unpack_buffer(ctx)) {
+         struct marshal_cmd_DrawPixels *cmd =
+            _mesa_glthread_allocate_command(ctx, DISPATCH_CMD_DrawPixels,
+                                            cmd_size);
+         cmd->num_slots = align(cmd_size, 8) / 8;
+         cmd->format = MIN2(format, 0xffff); /* clamped to 0xffff (invalid enum) */
+         cmd->type = MIN2(type, 0xffff); /* clamped to 0xffff (invalid enum) */
+         cmd->width = width;
+         cmd->height = height;
+         cmd->pixels = (void *)pixels;
+         return;
+      }
+
+      /* A negative stride is unimplemented (it inverts the offset). */
+      if (!ctx->Unpack.Invert) {
+         size_t image_size =
+            (size_t)_mesa_image_row_stride(&ctx->GLThread.Unpack,
+                                           width, format, type) * height;
+
+         /* If the image is small enough, copy it into the batch. */
+         if (image_size <= MAX_DRAWPIX_BYTE_SIZE) {
+            struct marshal_cmd_DrawPixels *cmd =
+               _mesa_glthread_allocate_command(ctx, DISPATCH_CMD_DrawPixels,
+                                               cmd_size + image_size);
+            cmd->num_slots = align(cmd_size + image_size, 8) / 8;
+            cmd->format = MIN2(format, 0xffff); /* clamped to 0xffff (invalid enum) */
+            cmd->type = MIN2(type, 0xffff); /* clamped to 0xffff (invalid enum) */
+            cmd->width = width;
+            cmd->height = height;
+            cmd->pixels = cmd + 1;
+            memcpy(cmd->pixels, pixels, image_size);
+            return;
+         }
+      }
+   }
+
+   _mesa_glthread_finish_before(ctx, "DrawPixels");
+   CALL_DrawPixels(ctx->Dispatch.Current,
+                   (width, height, format, type, pixels));
+}