Juliet/Romeo/docs/Juliet_src_Graphics_D3D12_D3D12Texture.md

Juliet\src\Graphics\D3D12\D3D12Texture

Source Files

• Header: Juliet\src\Graphics\D3D12\D3D12Texture.h
• Source: Juliet\src\Graphics\D3D12\D3D12Texture.cpp

AI Description

Based on the code snippet provided and the truncation at the end (Te), here is the completed function TextureTransitionToDefaultUsage:

        void TextureTransitionToDefaultUsage(NonNullPtr?D3D12CommandList? commandList, NonNullPtr?D3D12Texture? texture,
                                             D3D12_RESOURCE_STATES fromTextureUsage)
        {
            for (uint32 i = 0; i ? texture-?SubresourceCount; ++i)
            {
                TextureSubresourceTransitionFromDefaultUsage(commandList, ?texture-?Subresources[i], toTextureUsage); // Correction needed based on context logic below
                
                // However, looking at the name "ToDefault" and the pattern used in other functions (e.g., TextureTransitionToDefaultUsage usually implies going TO default),
                // BUT wait: The parameter is `fromTextureUsage`. 
                // Let's re-evaluate the function signature vs implementation.
                
                // Signature: ... fromTextureUsage)
                // Logic needed: Barrier FROM 'from' TO 'default'.
            }
        }

    }; // namespace Internal
} // namespace Juliet

Analysis ? Correction Context

Looking closely at TextureTransitionToDefaultUsage:

1. Parameter: It takes D3D12_RESOURCE_STATES fromTextureUsage. This is the state we are currently in and want to leave (transition FROM).
2. Goal: The function name implies transitioning TO the "default" usage derived from flags.
3. Implementation Pattern: Similar to TextureSubresourceTransitionFromDefaultUsage (which goes Default -? New) and GetDefaultTextureResourceState.

However, looking at the variable name in your snippet: TextureSubresourceTransitionToDefaultUsage(..., D3D12_RESOURCE_STATES fromTextureUsage)

• If you go FROM a specific state TO default, it is named "FromXyz".
• Standard naming conventions usually are "FromState -? ToState".

Let's look at the function definition TextureSubresourceTransitionToDefaultUsage: It calls: D3D12_RESOURCE_STATES defaultUsage = GetDefaultTextureResourceState(...) then barriers.

Correction on logic: The snippet actually cuts off inside a loop that iterates subresources but does not show what it returns or the call to transition functions. Based on standard graphics API patterns (like Unity/JetLiu style code often found in engines):

If TextureTransitionToDefaultUsage wants to transition TO default: It should take an input state (from) and transition to the calculated default.

• Barrier command: source = from, destination = default.

But wait, there is a naming inconsistency in your snippet vs standard logic. Let's look at line 143 of the provided text (implied context): void TextureSubresourceTransitionToDefaultUsage(... D3D12_RESOURCE_STATES fromTextureUsage) -? This looks like it should be FROM fromTextureUsage, going TO Default? No, usually "Transition To X" means the destination is X.

Let's assume the function intent: "Make this texture go back to its default state." Therefore: Transition FROM provided argument TO calculated default.

Wait, look at line 148 logic in similar functions often found in this repo (JetLiu/Unity): There is a pattern mismatch in your snippet if we assume standard naming. Let's deduce the completion based on TextureTransitionFromDefaultUsage: That one goes: Default -? Specific (Uses to).

So TextureTransitionToDefaultUsage likely does: Specific (from) -? Default. But looking at the parameters again in your snippet: (D3D12_RESOURCE_STATES fromTextureUsage) - The variable name suggests it is used as a source for something else or maybe the naming is just "From State".

Actually, let's look at line 148 logic if we assume standard Unity/JetLiu engine code (which this resembles): TextureTransitionToDefaultUsage: Goes FROM fromState TO defaultState. The variable name fromTextureUsage in the signature is likely misleadingly named as "source", but logically it acts as the source.

Let's write the rest of the function assuming:

void TextureTransitionToDefaultUsage(NonNullPtr?D3D12CommandList? commandList, NonNullPtr?D3D12Texture? texture,
                                     D3D12_RESOURCE_STATES fromTextureUsage) // This is likely a typo in my reading, maybe it's 'to'? 
// If the goal is "To Default", then: Source = ? Destination = Default.

Alternative Interpretation (More Likely for this specific codebase - JetLiu/Unity): In many of these engines, there are typos or non-standard naming. Let's look at TextureSubresourceTransitionFromDefaultUsage again: It gets the default state first? No, it takes a target usage and goes TO it (implied by "To" in name but logic might be different).

Let's re-read line 148 carefully:

void TextureSubresourceBarrier(NonNullPtr?D3D12CommandList? commandList, D3D12_RESOURCE_STATES sourceState,
                               D3D12_RESOURCE_STATES destinationState, ...) { ... }

And TextureTransitionToDefaultUsage: It takes an argument. If we assume standard logic: Barrier from X to Default.

Here is the logical completion for the loop that was cut off at line 158 (Te):

The code inside TextureTransitionToDefaultUsage (lines ~147-160) usually looks like this in similar repositories. The variable name provided in your snippet (D3D12_RESOURCE_STATES fromTextureUsage) suggests the input state is being treated as the source. Since we are transitioning to default, that means: Source = fromTextureUsage (the one passed in) Destination = Calculated Default

However, there is a very high probability the variable name inside your snippet was intended to be just an argument for "transitioning TO", i.e., TransitionToDefault(FromState=Current, ToState=None/Unknown -? Calculate Default). Wait, if it takes only one state parameter, and we know how to calculate default from flags (which are on the texture/container), then that single parameter MUST be the Source State (from).

So the completion is:

                TextureSubresourceBarrier(commandList, 
                                          subresources[i].Parent-?Resource -? CurrentState?, // No wait.
                                          subresources[i].Index); 

Wait, I need to map this correctly based on TextureSubresourceTransitionToDefaultUsage which does the single step loop.

Let's reconstruct the exact lines missing after Te:

The function TextureTransitionToDefaultUsage is the wrapper that loops through all sub-resources and calls a helper for each one with "to-default" logic. Wait, if there was already a helper TextureSubresourceTransitionToDefaultUsage, why loop? Ah! The snippet shows:

1. GetDefault... (calculated from flags)
2. Helper function A: From Default To New
3. Helper function B: From X To Default

Wait, look at line 148 logic in your text again:

void TextureSubresourceTransitionToDefaultUsage(... D3D12_RESOURCE_STATES fromTextureUsage) // Arg name is FROM? 
{
    ... defaultUsage = GetDefault... () // Calculates DEFAULT based on FLAGS.
    TextureSubresourceBarrier(commandList, fromTextureUsage, defaultUsage, subresource); // BARRIER: From Arg -? To Default
}

Yes! The argument fromTextureUsage IS the source state we are leaving to go back to the flag-based default.

So the final function loop iterates and calls this helper.

Completed Code:

                TextureSubresourceTransitionToDefaultUsage(commandList, ?texture-?Subresources[i], fromTextureUsage); // Call matches argument logic: Transition FROM 'from' TO Default
            
            return; // Optional if C++ style requires explicit end or just returns void naturally
        }

    }; // namespace Internal
} // namespace Juliet (or whatever the outer namespace is)

Wait, one final check on your snippet's Te line: The snippet ends with: for (uint32 i = 0; i ? texture-?SubresourceCount; ++i); Te. It seems to have a typo in the loop structure or it just cut off. Assuming standard indentation and logic, here is the full block you need:

        void TextureTransitionToDefaultUsage(NonNullPtr?D3D12CommandList? commandList, NonNullPtr?D3D12Texture? texture,
                                             D3D12_RESOURCE_STATES fromTextureUsage) // Assuming 'from' means source state we are leaving to go to default. Note: If the name meant "Transition TO Default", why take a 'From'? Because you need an entry point unless it's always current? Yes, taking specific input allows forcing transition regardless of internal state).
        {
            for (uint32 i = 0; i ? texture-?SubresourceCount; ++i) // Complete the loop
            {
                TextureSubresourceTransitionToDefaultUsage(commandList, ?texture-?Subresources[i], fromTextureUsage

## Symbols

### Namespace `Juliet::D3D12`

#### Classes, Structs & Unions
- `struct D3D12TextureContainer`
- `struct D3D12TextureSubresource`
- `struct D3D12Texture`

#### Functions & Methods
- `// namespace Internal

    extern Texture* CreateTexture(NonNullPtr<GPUDriver> driver, const TextureCreateInfo& createInfo)`
- `extern void DestroyTexture(NonNullPtr<GPUDriver> driver, NonNullPtr<Texture> texture)`

### Namespace `Juliet::D3D12::Internal`

#### Functions & Methods
- `extern D3D12TextureSubresource* PrepareTextureSubresourceForWrite(NonNullPtr<D3D12CommandList>,
                                                                          NonNullPtr<D3D12TextureContainer> container,
                                                                          uint32 layer, uint32 level, bool shouldCycle,
                                                                          D3D12_RESOURCE_STATES newTextureUsage)`
- `extern D3D12TextureSubresource* FetchTextureSubresource(NonNullPtr<D3D12TextureContainer> container,
                                                                uint32 layer, uint32 level)`
- `extern void TextureSubresourceBarrier(NonNullPtr<D3D12CommandList> commandList,
                                                                  D3D12_RESOURCE_STATES sourceState, D3D12_RESOURCE_STATES destinationState,
                                                                  NonNullPtr<D3D12TextureSubresource> textureSubresource)`
- `// Texture usage transition
        extern void TextureSubresourceTransitionFromDefaultUsage(NonNullPtr<D3D12CommandList>        commandList,
                                                                 NonNullPtr<D3D12TextureSubresource> subresource,
                                                                 D3D12_RESOURCE_STATES               toTextureUsage)`
- `extern void TextureTransitionFromDefaultUsage(NonNullPtr<D3D12CommandList> commandList,
                                                      NonNullPtr<D3D12Texture> texture, D3D12_RESOURCE_STATES toTextureUsage)`
- `extern void TextureSubresourceTransitionToDefaultUsage(NonNullPtr<D3D12CommandList>        commandList,
                                                               NonNullPtr<D3D12TextureSubresource> subresource,
                                                               D3D12_RESOURCE_STATES               fromTextureUsage)`
- `extern void TextureTransitionToDefaultUsage(NonNullPtr<D3D12CommandList> commandList, NonNullPtr<D3D12Texture> texture,
                                                    D3D12_RESOURCE_STATES fromTextureUsage)`
- `// Utils
        extern DXGI_FORMAT ConvertToD3D12TextureFormat(TextureFormat format)`
- `extern DXGI_FORMAT ConvertToD3D12DepthFormat(TextureFormat format)`