sokol_gfx.h: validate sg_buffer_usage and sg_image_usage flags

sokol_gfx.h

@@ -4001,6 +4001,8 @@ typedef struct sg_frame_stats {
     _SG_LOGITEM_XMACRO(APPLY_BINDINGS_STORAGE_BUFFER_TRACKER_EXHAUSTED, "sg_apply_bindings: too many read/write storage buffers in pass (bump sg_desc.max_dispatch_calls_per_pass") \
     _SG_LOGITEM_XMACRO(DRAW_WITHOUT_BINDINGS, "attempting to draw without resource bindings") \
     _SG_LOGITEM_XMACRO(VALIDATE_BUFFERDESC_CANARY, "sg_buffer_desc not initialized") \
+    _SG_LOGITEM_XMACRO(VALIDATE_BUFFERDESC_IMMUTABLE_DYNAMIC_STREAM, "sg_buffer_desc.usage: only one of .immutable, .dynamic_update, .stream_update can be true") \
+    _SG_LOGITEM_XMACRO(VALIDATE_BUFFERDESC_SEPARATE_BUFFER_TYPES, "sg_buffer_desc.usage: on WebGL2, only one of .vertex_buffer or .index_buffer can be true (check sg_features.separate_buffer_types)") \
     _SG_LOGITEM_XMACRO(VALIDATE_BUFFERDESC_EXPECT_NONZERO_SIZE, "sg_buffer_desc.size must be greater zero") \
     _SG_LOGITEM_XMACRO(VALIDATE_BUFFERDESC_EXPECT_MATCHING_DATA_SIZE, "sg_buffer_desc.size and .data.size must be equal") \
     _SG_LOGITEM_XMACRO(VALIDATE_BUFFERDESC_EXPECT_ZERO_DATA_SIZE, "sg_buffer_desc.data.size expected to be zero") \
@@ -4010,6 +4012,8 @@ typedef struct sg_frame_stats {
     _SG_LOGITEM_XMACRO(VALIDATE_IMAGEDATA_NODATA, "sg_image_data: no data (.ptr and/or .size is zero)") \
     _SG_LOGITEM_XMACRO(VALIDATE_IMAGEDATA_DATA_SIZE, "sg_image_data: data size doesn't match expected surface size") \
     _SG_LOGITEM_XMACRO(VALIDATE_IMAGEDESC_CANARY, "sg_image_desc not initialized") \
+    _SG_LOGITEM_XMACRO(VALIDATE_IMAGEDESC_IMMUTABLE_DYNAMIC_STREAM, "sg_image_desc.usage: only one of .immutable, .dynamic_update, .stream_update can be true") \
+    _SG_LOGITEM_XMACRO(VALIDATE_IMAGEDESC_RENDER_VS_STORAGE_ATTACHMENT, "sg_image_desc.usage: only one of .render_attachemnt or .storage_attachment can be true") \
     _SG_LOGITEM_XMACRO(VALIDATE_IMAGEDESC_WIDTH, "sg_image_desc.width must be > 0") \
     _SG_LOGITEM_XMACRO(VALIDATE_IMAGEDESC_HEIGHT, "sg_image_desc.height must be > 0") \
     _SG_LOGITEM_XMACRO(VALIDATE_IMAGEDESC_RT_PIXELFORMAT, "invalid pixel format for render-target image") \
@@ -17707,6 +17711,10 @@ _SOKOL_PRIVATE bool _sg_validate_end(void) {
 }
 #endif
 
+_SOKOL_PRIVATE bool _sg_one(bool b0, bool b1, bool b2) {
+    return (b0 && !b1 && !b2) || (!b0 && b1 && !b2) || (!b0 && !b1 && b2);
+}
+
 _SOKOL_PRIVATE bool _sg_validate_buffer_desc(const sg_buffer_desc* desc) {
     #if !defined(SOKOL_DEBUG)
         _SOKOL_UNUSED(desc);
@@ -17720,6 +17728,10 @@ _SOKOL_PRIVATE bool _sg_validate_buffer_desc(const sg_buffer_desc* desc) {
         _SG_VALIDATE(desc->_start_canary == 0, VALIDATE_BUFFERDESC_CANARY);
         _SG_VALIDATE(desc->_end_canary == 0, VALIDATE_BUFFERDESC_CANARY);
         _SG_VALIDATE(desc->size > 0, VALIDATE_BUFFERDESC_EXPECT_NONZERO_SIZE);
+        _SG_VALIDATE(_sg_one(desc->usage.immutable, desc->usage.dynamic_update, desc->usage.stream_update), VALIDATE_BUFFERDESC_IMMUTABLE_DYNAMIC_STREAM);
+        if (_sg.features.separate_buffer_types) {
+            _SG_VALIDATE(_sg_one(desc->usage.vertex_buffer, desc->usage.index_buffer, desc->usage.storage_buffer), VALIDATE_BUFFERDESC_SEPARATE_BUFFER_TYPES);
+        }
         bool injected = (0 != desc->gl_buffers[0]) ||
                         (0 != desc->mtl_buffers[0]) ||
                         (0 != desc->d3d11_buffer) ||
@@ -17779,6 +17791,10 @@ _SOKOL_PRIVATE bool _sg_validate_image_desc(const sg_image_desc* desc) {
         _sg_validate_begin();
         _SG_VALIDATE(desc->_start_canary == 0, VALIDATE_IMAGEDESC_CANARY);
         _SG_VALIDATE(desc->_end_canary == 0, VALIDATE_IMAGEDESC_CANARY);
+        _SG_VALIDATE(_sg_one(desc->usage.immutable, desc->usage.dynamic_update, desc->usage.stream_update), VALIDATE_IMAGEDESC_IMMUTABLE_DYNAMIC_STREAM);
+        if (desc->usage.render_attachment || desc->usage.storage_attachment) {
+            _SG_VALIDATE(_sg_one(desc->usage.render_attachment, desc->usage.storage_attachment, false), VALIDATE_IMAGEDESC_RENDER_VS_STORAGE_ATTACHMENT);
+        }
         _SG_VALIDATE(desc->width > 0, VALIDATE_IMAGEDESC_WIDTH);
         _SG_VALIDATE(desc->height > 0, VALIDATE_IMAGEDESC_HEIGHT);
         const sg_pixel_format fmt = desc->pixel_format;