Betsy: Add caching and BC1 compression support

core/io/image.cpp

@@ -2751,6 +2751,19 @@ Error Image::compress_from_channels(CompressMode p_mode, UsedChannels p_channels
 
 			} break;
 
+			case COMPRESS_S3TC: {
+				// BC3 is unsupported currently.
+				if ((p_channels == USED_CHANNELS_RGB || p_channels == USED_CHANNELS_L) && _image_compress_bc_rd_func) {
+					Error result = _image_compress_bc_rd_func(this, p_channels);
+
+					// If the image was compressed successfully, we return here. If not, we fall back to the default compression scheme.
+					if (result == OK) {
+						return OK;
+					}
+				}
+
+			} break;
+
 			default: {
 			}
 		}
@@ -3138,6 +3151,7 @@ void (*Image::_image_compress_etc1_func)(Image *) = nullptr;
 void (*Image::_image_compress_etc2_func)(Image *, Image::UsedChannels) = nullptr;
 void (*Image::_image_compress_astc_func)(Image *, Image::ASTCFormat) = nullptr;
 Error (*Image::_image_compress_bptc_rd_func)(Image *, Image::UsedChannels) = nullptr;
+Error (*Image::_image_compress_bc_rd_func)(Image *, Image::UsedChannels) = nullptr;
 void (*Image::_image_decompress_bc)(Image *) = nullptr;
 void (*Image::_image_decompress_bptc)(Image *) = nullptr;
 void (*Image::_image_decompress_etc1)(Image *) = nullptr;

core/io/image.h

@@ -160,6 +160,7 @@ class Image : public Resource {
 	static void (*_image_compress_astc_func)(Image *, ASTCFormat p_format);
 
 	static Error (*_image_compress_bptc_rd_func)(Image *, UsedChannels p_channels);
+	static Error (*_image_compress_bc_rd_func)(Image *, UsedChannels p_channels);
 
 	static void (*_image_decompress_bc)(Image *);
 	static void (*_image_decompress_bptc)(Image *);

doc/classes/ProjectSettings.xml

@@ -2890,10 +2890,13 @@
 		<member name="rendering/textures/lossless_compression/force_png" type="bool" setter="" getter="" default="false">
 			If [code]true[/code], the texture importer will import lossless textures using the PNG format. Otherwise, it will default to using WebP.
 		</member>
+		<member name="rendering/textures/vram_compression/cache_gpu_compressor" type="bool" setter="" getter="" default="true">
+			If [code]true[/code], the GPU texture compressor will cache the local RenderingDevice and its resources (shaders and pipelines), allowing for faster subsequent imports at a memory cost.
+		</member>
 		<member name="rendering/textures/vram_compression/compress_with_gpu" type="bool" setter="" getter="" default="true">
-			If [code]true[/code], the texture importer will utilize the GPU for compressing textures, which makes large textures import significantly faster.
+			If [code]true[/code], the texture importer will utilize the GPU for compressing textures, improving the import time of large images.
 			[b]Note:[/b] This setting requires either Vulkan or D3D12 available as a rendering backend.
-			[b]Note:[/b] Currently this only affects BC6H compression, which is used on Desktop and Console for HDR images.
+			[b]Note:[/b] Currently this only affects BC1 and BC6H compression, which are used on Desktop and Console for fully opaque and HDR images respectively.
 		</member>
 		<member name="rendering/textures/vram_compression/import_etc2_astc" type="bool" setter="" getter="" default="false">
 			If [code]true[/code], the texture importer will import VRAM-compressed textures using the Ericsson Texture Compression 2 algorithm for lower quality textures and normal maps and Adaptable Scalable Texture Compression algorithm for high quality textures (in 4×4 block size).

modules/betsy/SCsub

@@ -4,6 +4,7 @@ Import("env_modules")
 
 env_betsy = env_modules.Clone()
 env_betsy.GLSL_HEADER("bc6h.glsl")
+env_betsy.GLSL_HEADER("bc1.glsl")
 env_betsy.Depends(Glob("*.glsl.gen.h"), ["#glsl_builders.py"])
 
 # Thirdparty source files