Fix pixel pitch handling for DXGI_FORMAT_R16G16B16A16_FLOAT

[cgutman]

Description

Pixel pitch was being calculated incorrectly for DXGI_FORMAT_R16G16B16A16_FLOAT (which is a 64-bit format), so our buffers weren't large enough to contain the full image. Additionally, display_vram_t::dummy_img() had a subtle bug where it was using int[] as the data buffer type (which is 4 bytes per element) instead of using uint8_t[] and the actual pixel_pitch value.

The combination of these would cause the display driver to read out of bounds inside CreateTexture2D() when attempting to populate the dummy texture during initialization if HDR was enabled in Windows.

With this change, Sunshine can now initialize without crashing on systems with HDR enabled. For semi-usable streaming, we also need #522 merged.

Screenshot

Issues Fixed or Closed

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Dependency update (updates to dependencies)
• Documentation update (changes to documentation)
• Repository update (changes to repository files, e.g. .github/...)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated the in code docstring/documentation-blocks for new or existing methods/components

Branch Updates

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