From ed020691cc78b4b48e6b510daa70b664fc758068 Mon Sep 17 00:00:00 2001
From: cosmonaut <evan@moonside.games>
Date: Tue, 1 Mar 2022 22:21:07 -0800
Subject: [PATCH] add swapchain format query

---
 include/Refresh.h           |  8 +++-
 src/Refresh.c               | 11 ++++++
 src/Refresh_Driver.h        |  6 +++
 src/Refresh_Driver_Vulkan.c | 74 ++++++++++++++++++++++++++++---------
 4 files changed, 81 insertions(+), 18 deletions(-)

diff --git a/include/Refresh.h b/include/Refresh.h
index d9b8c16..ddb7f92 100644
--- a/include/Refresh.h
+++ b/include/Refresh.h
@@ -1242,6 +1242,12 @@ REFRESHAPI Refresh_Texture* Refresh_AcquireSwapchainTexture(
 	void *windowHandle
 );
 
+/* Returns the format of the swapchain for the given window. */
+REFRESHAPI Refresh_TextureFormat Refresh_GetSwapchainFormat(
+	Refresh_Device *device,
+	void *windowHandle
+);
+
 /* Submits all of the enqueued commands. */
 REFRESHAPI void Refresh_Submit(
 	Refresh_Device* device,
@@ -1249,7 +1255,7 @@ REFRESHAPI void Refresh_Submit(
 	Refresh_CommandBuffer **pCommandBuffers
 );
 
-/* Waits for the previous submission to complete. */
+/* Waits for all submissions to complete. */
 REFRESHAPI void Refresh_Wait(
 	Refresh_Device *device
 );
diff --git a/src/Refresh.c b/src/Refresh.c
index f6dfe94..c71981e 100644
--- a/src/Refresh.c
+++ b/src/Refresh.c
@@ -725,6 +725,17 @@ Refresh_Texture* Refresh_AcquireSwapchainTexture(
 	);
 }
 
+Refresh_TextureFormat Refresh_GetSwapchainFormat(
+	Refresh_Device *device,
+	void *windowHandle
+) {
+	if (device == NULL) { return 0; }
+	return device->GetSwapchainFormat(
+		device->driverData,
+		windowHandle
+	);
+}
+
 void Refresh_Submit(
 	Refresh_Device *device,
 	uint32_t commandBufferCount,
diff --git a/src/Refresh_Driver.h b/src/Refresh_Driver.h
index 95abaaa..5d1fdfe 100644
--- a/src/Refresh_Driver.h
+++ b/src/Refresh_Driver.h
@@ -448,6 +448,11 @@ struct Refresh_Device
 		void *windowHandle
 	);
 
+	Refresh_TextureFormat (*GetSwapchainFormat)(
+		Refresh_Renderer *driverData,
+		void *windowHandle
+	);
+
 	void(*Submit)(
 		Refresh_Renderer *driverData,
 		uint32_t commandBufferCount,
@@ -504,6 +509,7 @@ struct Refresh_Device
 	ASSIGN_DRIVER_FUNC(BindComputeTextures, name) \
 	ASSIGN_DRIVER_FUNC(AcquireCommandBuffer, name) \
 	ASSIGN_DRIVER_FUNC(AcquireSwapchainTexture, name) \
+	ASSIGN_DRIVER_FUNC(GetSwapchainFormat, name) \
 	ASSIGN_DRIVER_FUNC(Submit, name) \
 	ASSIGN_DRIVER_FUNC(Wait, name)
 
diff --git a/src/Refresh_Driver_Vulkan.c b/src/Refresh_Driver_Vulkan.c
index 94d927f..b199b73 100644
--- a/src/Refresh_Driver_Vulkan.c
+++ b/src/Refresh_Driver_Vulkan.c
@@ -3849,7 +3849,6 @@ static uint8_t VULKAN_INTERNAL_ChooseSwapSurfaceFormat(
 		}
 	}
 
-	Refresh_LogError("Desired surface format is unavailable.");
 	return 0;
 }
 
@@ -3961,7 +3960,7 @@ static CreateSwapchainResult VULKAN_INTERNAL_CreateSwapchain(
 		return CREATE_SWAPCHAIN_FAIL;
 	}
 
-	swapchainData->swapchainFormat = VK_FORMAT_B8G8R8A8_UNORM;
+	swapchainData->swapchainFormat = VK_FORMAT_R8G8B8A8_UNORM;
 	swapchainData->swapchainSwizzle.r = VK_COMPONENT_SWIZZLE_IDENTITY;
 	swapchainData->swapchainSwizzle.g = VK_COMPONENT_SWIZZLE_IDENTITY;
 	swapchainData->swapchainSwizzle.b = VK_COMPONENT_SWIZZLE_IDENTITY;
@@ -3973,22 +3972,36 @@ static CreateSwapchainResult VULKAN_INTERNAL_CreateSwapchain(
 		swapchainSupportDetails.formatsLength,
 		&swapchainData->surfaceFormat
 	)) {
-		renderer->vkDestroySurfaceKHR(
-			renderer->instance,
-			swapchainData->surface,
-			NULL
-		);
-		if (swapchainSupportDetails.formatsLength > 0)
-		{
-			SDL_free(swapchainSupportDetails.formats);
+		Refresh_LogWarn("RGBA8 swapchain unsupported, falling back to BGRA8 with swizzle");
+		swapchainData->swapchainFormat = VK_FORMAT_B8G8R8A8_UNORM;
+		swapchainData->swapchainSwizzle.r = VK_COMPONENT_SWIZZLE_B;
+		swapchainData->swapchainSwizzle.g = VK_COMPONENT_SWIZZLE_G;
+		swapchainData->swapchainSwizzle.b = VK_COMPONENT_SWIZZLE_R;
+		swapchainData->swapchainSwizzle.a = VK_COMPONENT_SWIZZLE_A;
+
+		if (!VULKAN_INTERNAL_ChooseSwapSurfaceFormat(
+			swapchainData->swapchainFormat,
+			swapchainSupportDetails.formats,
+			swapchainSupportDetails.formatsLength,
+			&swapchainData->surfaceFormat
+		)) {
+			renderer->vkDestroySurfaceKHR(
+				renderer->instance,
+				swapchainData->surface,
+				NULL
+			);
+			if (swapchainSupportDetails.formatsLength > 0)
+			{
+				SDL_free(swapchainSupportDetails.formats);
+			}
+			if (swapchainSupportDetails.presentModesLength > 0)
+			{
+				SDL_free(swapchainSupportDetails.presentModes);
+			}
+			SDL_free(swapchainData);
+			Refresh_LogError("Device does not support swap chain format");
+			return CREATE_SWAPCHAIN_FAIL;
 		}
-		if (swapchainSupportDetails.presentModesLength > 0)
-		{
-			SDL_free(swapchainSupportDetails.presentModes);
-		}
-		SDL_free(swapchainData);
-		Refresh_LogError("Device does not support swap chain format");
-		return CREATE_SWAPCHAIN_FAIL;
 	}
 
 	if (!VULKAN_INTERNAL_ChooseSwapPresentMode(
@@ -8626,6 +8639,33 @@ static Refresh_Texture* VULKAN_AcquireSwapchainTexture(
 	return (Refresh_Texture*) swapchainTexture;
 }
 
+static Refresh_TextureFormat VULKAN_GetSwapchainFormat(
+	Refresh_Renderer *driverData,
+	void *windowHandle
+) {
+	VulkanSwapchainData *swapchainData = (VulkanSwapchainData*) SDL_GetWindowData(windowHandle, WINDOW_SWAPCHAIN_DATA);
+
+	if (swapchainData == NULL)
+	{
+		Refresh_LogWarn("No swapchain for this window!");
+		return 0;
+	}
+
+	if (swapchainData->swapchainFormat == VK_FORMAT_R8G8B8A8_UNORM)
+	{
+		return REFRESH_TEXTUREFORMAT_R8G8B8A8;
+	}
+	else if (swapchainData->swapchainFormat == VK_FORMAT_B8G8R8A8_UNORM)
+	{
+		return REFRESH_TEXTUREFORMAT_B8G8R8A8;
+	}
+	else
+	{
+		Refresh_LogWarn("Unrecognized swapchain format!");
+		return 0;
+	}
+}
+
 /* Synchronization management */
 
 static VkFence VULKAN_INTERNAL_AcquireFence(