From f84d6a6e18f8fffbfc619eb332ef3fbe0a0dd98b Mon Sep 17 00:00:00 2001
From: dmaivel <dvmaivel@gmail.com>
Date: Mon, 15 Jul 2024 00:20:39 -0400
Subject: [PATCH] Implement glMapBuffer, glMapNamedBuffer

---
 src/client/glimpl.c    | 59 ++++++++++++++++++++++++++----------------
 src/server/processor.c | 11 ++++++++
 2 files changed, 48 insertions(+), 22 deletions(-)

diff --git a/src/client/glimpl.c b/src/client/glimpl.c
index 422487e..75ba1d2 100644
--- a/src/client/glimpl.c
+++ b/src/client/glimpl.c
@@ -981,13 +981,34 @@ static void glimpl_buffer_clear_data(int cmd, bool is_subdata, GLenum buffer, GL
     pb_push(*(unsigned int*)data); // to-do: technically should look at type first, dont care
 }
 
+static void glimpl_get_buffer_parameter(int cmd, GLuint buffer, GLenum pname, GLint* params)
+{
+    pb_push(cmd);
+    pb_push(buffer);
+    pb_push(pname);
+
+    glimpl_submit();
+    *params = pb_read(SGL_OFFSET_REGISTER_RETVAL);
+}
+
 static void *glimpl_map_buffer_range(int cmd, GLenum buffer, GLintptr offset, GLsizeiptr length, GLbitfield access)
 {
+    bool ranged = true;
     if (glimpl_map_buffer.in_use) {
         fprintf(stderr, "glimpl_map_buffer_range: map buffer already in use, returning NULL\n");
         return NULL;
     }
 
+    /*
+     * length is 0 when this function is called by glMapBuffer, glMapNamedBuffer
+     */
+    if (length == 0) {
+        bool is_named = cmd == SGL_CMD_MAPNAMEDBUFFER;
+        int get_param_cmd = !is_named ? SGL_CMD_GETBUFFERPARAMETERIV : SGL_CMD_GETNAMEDBUFFERPARAMETERIV;
+        glimpl_get_buffer_parameter(get_param_cmd, buffer, GL_BUFFER_SIZE, (GLint*)&length);
+        ranged = false;
+    }
+
     glimpl_map_buffer = (struct gl_map_buffer){
         /* target = */  buffer,
         /* mem = */     scratch_buffer_get(length), // calloc(length, 1), // glimpl_map_buffer.mem,
@@ -997,11 +1018,21 @@ static void *glimpl_map_buffer_range(int cmd, GLenum buffer, GLintptr offset, GL
         /* in_use = */  true
     };
 
+    /*
+     * this function supports both glMapBuffer and glMapBufferRange; as such, these functions have
+     * different parameters to be pushed
+     */
     pb_push(cmd);
-    pb_push(buffer);
-    pb_push(offset);
-    pb_push(length);
-    pb_push(access);
+    if (ranged) {
+        pb_push(buffer);
+        pb_push(offset);
+        pb_push(length);
+        pb_push(access);
+    }
+    else {
+        pb_push(buffer);
+        pb_push(access);
+    }
 
     glimpl_submit();
 
@@ -1010,16 +1041,6 @@ static void *glimpl_map_buffer_range(int cmd, GLenum buffer, GLintptr offset, GL
     return glimpl_map_buffer.mem;
 }
 
-static void glimpl_get_buffer_parameter(int cmd, GLuint buffer, GLenum pname, GLint* params)
-{
-    pb_push(cmd);
-    pb_push(buffer);
-    pb_push(pname);
-
-    glimpl_submit();
-    *params = pb_read(SGL_OFFSET_REGISTER_RETVAL);
-}
-
 static void glimpl_invalidate_framebuffer(int cmd, bool is_subframebuffer, GLenum framebuffer, GLsizei n_attachments, 
         const GLenum *attachments, int x, int y, int width, int height)
 {
@@ -7303,8 +7324,7 @@ void glGetBufferSubData(GLenum target, GLintptr offset, GLsizeiptr size, void* d
 
 void* glMapBuffer(GLenum target, GLenum access)
 {
-    STUB();
-    return NULL;
+    return glimpl_map_buffer_range(SGL_CMD_MAPBUFFER, target, 0, 0, access);
 }
 
 void glGetBufferParameteriv(GLenum target, GLenum pname, GLint* params)
@@ -9459,12 +9479,7 @@ void glClearNamedBufferSubData(GLuint buffer, GLenum internalformat, GLintptr of
 
 void* glMapNamedBuffer(GLuint buffer, GLenum access)
 {
-    /*
-     * stub, refer to glMapBuffer
-     * to-do: print stubs to stderr?
-     */
-    STUB();
-    return NULL;
+    return glimpl_map_buffer_range(SGL_CMD_MAPNAMEDBUFFER, buffer, 0, 0, access);
 }
 
 void* glMapNamedBufferRange(GLuint buffer, GLintptr offset, GLsizeiptr length, GLbitfield access)
diff --git a/src/server/processor.c b/src/server/processor.c
index b56e4de..023535e 100644
--- a/src/server/processor.c
+++ b/src/server/processor.c
@@ -4781,6 +4781,13 @@ void sgl_cmd_processor_start(struct sgl_cmd_processor_args args)
                 glVertexAttribIPointer(index, size, type, stride, !is_value_likely_an_offset((void*)(uintptr_t)ptr) ? uploaded : (void*)(uintptr_t)ptr);
                 break;
             }
+            case SGL_CMD_MAPBUFFER: {
+                int target = *pb++,
+                    access = *pb++;
+                map_buffer = glMapBuffer(target, access);
+                map_buffer_offset = 0;
+                break;
+            }
             case SGL_CMD_MAPBUFFERRANGE: {
                 int target = *pb++,
                     offset = *pb++,
@@ -5504,6 +5511,10 @@ void sgl_cmd_processor_start(struct sgl_cmd_processor_args args)
                 break;
             }
             case SGL_CMD_MAPNAMEDBUFFER: {
+                int target = *pb++,
+                    access = *pb++;
+                map_buffer = glMapNamedBuffer(target, access);
+                map_buffer_offset = 0;
                 break;
             }
             case SGL_CMD_MAPNAMEDBUFFERRANGE: {