gbm: Expose bo buffer mapping (#12)

* expose bo buffer mapping * update comment * implement endDataPtr to unmap gbm buffer
hyprwm · Jul 12, 2024 · 815df06 · 815df06
1 parent 47d95b8
commit 815df06
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Showing 2 changed files with 35 additions and 9 deletions.
diff --git a/include/aquamarine/allocator/GBM.hpp b/include/aquamarine/allocator/GBM.hpp
@@ -14,20 +14,24 @@ namespace Aquamarine {
       public:
         virtual ~CGBMBuffer();
 
-        virtual eBufferCapability caps();
-        virtual eBufferType       type();
-        virtual void              update(const Hyprutils::Math::CRegion& damage);
-        virtual bool              isSynchronous();
-        virtual bool              good();
-        virtual SDMABUFAttrs      dmabuf();
+        virtual eBufferCapability                      caps();
+        virtual eBufferType                            type();
+        virtual void                                   update(const Hyprutils::Math::CRegion& damage);
+        virtual bool                                   isSynchronous();
+        virtual bool                                   good();
+        virtual SDMABUFAttrs                           dmabuf();
+        virtual std::tuple<uint8_t*, uint32_t, size_t> beginDataPtr(uint32_t flags);
+        virtual void                                   endDataPtr();
 
       private:
         CGBMBuffer(const SAllocatorBufferParams& params, Hyprutils::Memory::CWeakPointer<CGBMAllocator> allocator_, Hyprutils::Memory::CSharedPointer<CSwapchain> swapchain);
 
         Hyprutils::Memory::CWeakPointer<CGBMAllocator> allocator;
 
         // gbm stuff
-        gbm_bo*      bo = nullptr;
+        gbm_bo*      bo         = nullptr;
+        void*        boBuffer   = nullptr;
+        void*        gboMapping = nullptr;
         SDMABUFAttrs attrs{.success = false};
 
         friend class CGBMAllocator;

diff --git a/src/allocator/GBM.cpp b/src/allocator/GBM.cpp
@@ -53,7 +53,8 @@ static SDRMFormat guessFormatFrom(std::vector<SDRMFormat> formats, bool cursor)
 }
 
 Aquamarine::CGBMBuffer::CGBMBuffer(const SAllocatorBufferParams& params, Hyprutils::Memory::CWeakPointer<CGBMAllocator> allocator_,
-                                   Hyprutils::Memory::CSharedPointer<CSwapchain> swapchain) : allocator(allocator_) {
+                                   Hyprutils::Memory::CSharedPointer<CSwapchain> swapchain) :
+    allocator(allocator_) {
     if (!allocator)
         return;
 
@@ -158,8 +159,11 @@ Aquamarine::CGBMBuffer::CGBMBuffer(const SAllocatorBufferParams& params, Hypruti
 
 Aquamarine::CGBMBuffer::~CGBMBuffer() {
     events.destroy.emit();
-    if (bo)
+    if (bo) {
+        if (gboMapping)
+            gbm_bo_unmap(bo, gboMapping); // FIXME: is it needed before destroy?
         gbm_bo_destroy(bo);
+    }
     for (size_t i = 0; i < (size_t)attrs.planes; i++)
         close(attrs.fds.at(i));
 }
@@ -188,6 +192,24 @@ SDMABUFAttrs Aquamarine::CGBMBuffer::dmabuf() {
     return attrs;
 }
 
+std::tuple<uint8_t*, uint32_t, size_t> Aquamarine::CGBMBuffer::beginDataPtr(uint32_t flags) {
+    uint32_t dst_stride = 0;
+    if (boBuffer)
+        allocator->backend->log(AQ_LOG_ERROR, "beginDataPtr is called a second time without calling endDataPtr first. Returning old mapping");
+    else
+        boBuffer = gbm_bo_map(bo, 0, 0, attrs.size.x, attrs.size.y, flags, &dst_stride, &gboMapping);
+    // FIXME: assumes a 32-bit pixel format
+    return {(uint8_t*)boBuffer, attrs.format, attrs.size.x * attrs.size.y * 4};
+}
+
+void Aquamarine::CGBMBuffer::endDataPtr() {
+    if (gboMapping) {
+        gbm_bo_unmap(bo, gboMapping);
+        gboMapping = nullptr;
+        boBuffer   = nullptr;
+    }
+}
+
 CGBMAllocator::~CGBMAllocator() {
     if (gbmDevice)
         gbm_device_destroy(gbmDevice);