From 657e1de432300bdc7e8fb1610eb7b811b8f0ecc1 Mon Sep 17 00:00:00 2001
From: dmaivel <dvmaivel@gmail.com>
Date: Wed, 10 Jul 2024 18:13:32 -0400
Subject: [PATCH] Add `glimpl_download_buffer`

---
 inc/sharedgl.h      |  6 +++++
 src/client/glimpl.c | 57 ++++++++++++++++++++++++---------------------
 2 files changed, 36 insertions(+), 27 deletions(-)

diff --git a/inc/sharedgl.h b/inc/sharedgl.h
index 6000770..482351c 100644
--- a/inc/sharedgl.h
+++ b/inc/sharedgl.h
@@ -58,6 +58,12 @@
 #define UNPACK_A(packed) (((packed) >> 16) & 0xFFFF)
 #define UNPACK_B(packed) ((packed) & 0xFFFF)
 
+#ifdef _WIN32
+#   define FORCEINLINE __forceinline
+#else
+#   define FORCEINLINE __attribute__((always_inline))
+#endif
+
 inline bool is_value_likely_an_offset(const void *p)
 {
     uintptr_t v = (uintptr_t)p;
diff --git a/src/client/glimpl.c b/src/client/glimpl.c
index ccef8c8..8669bd4 100644
--- a/src/client/glimpl.c
+++ b/src/client/glimpl.c
@@ -683,6 +683,34 @@ static inline size_t glimpl_get_pixel_size(GLenum format)
     }
 }
 
+static inline void glimpl_upload_buffer(const void *data, size_t size)
+{
+    pb_push(SGL_CMD_VP_UPLOAD);
+    pb_push(CEIL_DIV(size, 4));
+    pb_memcpy((void*)data, size);
+}
+
+static inline void glimpl_download_buffer(void *dst, size_t size)
+{
+    int blocks = CEIL_DIV(size, SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES);
+    size_t count = size;
+
+    void *retval_v = pb_ptr(SGL_OFFSET_REGISTER_RETVAL_V);
+
+    for (int i = 0; i < blocks; i++) {
+        size_t true_count = count > SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES ? SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES : count;
+
+        pb_push(SGL_CMD_VP_DOWNLOAD);
+        pb_push(true_count);
+        
+        glimpl_submit();
+
+        memcpy((char*)dst + (i * SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES), retval_v, true_count);
+
+        count -= SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES;
+    }
+}
+
 static void glimpl_upload_texture(GLsizei width, GLsizei height, GLsizei depth, GLenum format, const void* pixels)
 {
     if (pixels == NULL) {
@@ -692,9 +720,7 @@ static void glimpl_upload_texture(GLsizei width, GLsizei height, GLsizei depth,
 
     size_t total_size = width * height * depth * glimpl_get_pixel_size(format);
 
-    pb_push(SGL_CMD_VP_UPLOAD);
-    pb_push(CEIL_DIV(total_size, 4));
-    pb_memcpy((void*)pixels, total_size);
+    glimpl_upload_buffer(pixels, total_size);
 }
 
 static inline void glimpl_push_client_pointers(int mode, int max_index)
@@ -866,13 +892,6 @@ static inline void glimpl_draw_elements(int mode, int type, int start, int end,
 
 #undef GET_MAX_INDEX
 
-static inline void glimpl_upload_buffer(const void *data, size_t size)
-{
-    pb_push(SGL_CMD_VP_UPLOAD);
-    pb_push(CEIL_DIV(size, 4));
-    pb_memcpy((void*)data, size);
-}
-
 static void glimpl_texture_subimage(int cmd, int n_dims, GLuint texture, GLint level, GLint xoffset, GLint yoffset, 
         GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const void *pixels)
 {
@@ -990,23 +1009,7 @@ static void *glimpl_map_buffer_range(int cmd, GLenum buffer, GLintptr offset, GL
 
     glimpl_submit();
 
-    int blocks = length / SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES + (length % SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES != 0);
-    size_t count = length;
-
-    void *retval_v = pb_ptr(SGL_OFFSET_REGISTER_RETVAL_V);
-
-    for (int i = 0; i < blocks; i++) {
-        size_t true_count = count > SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES ? SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES : count;
-
-        pb_push(SGL_CMD_VP_DOWNLOAD);
-        pb_push(true_count);
-        
-        glimpl_submit();
-
-        memcpy((char*)glimpl_map_buffer.mem + (i * SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES), retval_v, true_count);
-
-        count -= SGL_VP_DOWNLOAD_BLOCK_SIZE_IN_BYTES;
-    }
+    glimpl_download_buffer(glimpl_map_buffer.mem, length);
 
     return glimpl_map_buffer.mem;
 }