Generate mipmaps more efficiently

13_generate_mipmaps/Shaders/shaders.kong

@@ -67,22 +67,17 @@ const mip_constants: {
 #[set(mip)]
 const mip_source_texture: tex2d;
 
+#[set(mip)]
+const mip_source_sampler: sampler;
+
 #[set(mip), write]
 const mip_destination_texture: tex2d;
 
 #[compute, threads(8, 8, 1)]
 fun comp(): void {
 	var index: uint2 = dispatch_thread_id().xy;
 	if (index.x < mip_constants.size.x && index.y < mip_constants.size.y) {
-		var source_index0: uint2 = index * 2;
-		var source_index1: uint2 = uint2(source_index0.x + 1, source_index0.y);
-		var source_index2: uint2 = uint2(source_index0.x, source_index0.y + 1);
-		var source_index3: uint2 = uint2(source_index0.x + 1, source_index0.y + 1);
-
-		mip_destination_texture[index] =
-			(mip_source_texture[source_index0]
-			+ mip_source_texture[source_index1]
-			+ mip_source_texture[source_index2]
-			+ mip_source_texture[source_index0]) / 4.0;
+		var color: float4 = sample_lod(mip_source_texture, mip_source_sampler, float2(index.x / float(mip_constants.size.x), index.y / float(mip_constants.size.x)), 0);
+		mip_destination_texture[index] = color;
 	}
 }

13_generate_mipmaps/Sources/main.c

@@ -17,6 +17,7 @@ static fs_vertex_in_buffer vertices_fs;
 static kope_g5_buffer indices;
 static kope_g5_texture render_target;
 static kope_g5_sampler sampler;
+static kope_g5_sampler mip_sampler;
 static fs_set set;
 static mip_set mip_sets[4];
 
@@ -195,18 +196,35 @@ int kickstart(int argc, char **argv) {
 	fsparams.fs_sampler = &sampler;
 	kong_create_fs_set(&device, &fsparams, &set);
 
+	kope_g5_sampler_parameters mip_sampler_params = {0};
+	mip_sampler_params.address_mode_u = KOPE_G5_ADDRESS_MODE_REPEAT;
+	mip_sampler_params.address_mode_v = KOPE_G5_ADDRESS_MODE_REPEAT;
+	mip_sampler_params.address_mode_w = KOPE_G5_ADDRESS_MODE_REPEAT;
+	mip_sampler_params.mag_filter = KOPE_G5_FILTER_MODE_LINEAR;
+	mip_sampler_params.min_filter = KOPE_G5_FILTER_MODE_LINEAR;
+	mip_sampler_params.mipmap_filter = KOPE_G5_MIPMAP_FILTER_MODE_NEAREST;
+	mip_sampler_params.lod_min_clamp = 0;
+	mip_sampler_params.lod_max_clamp = 32;
+	mip_sampler_params.compare = KOPE_G5_COMPARE_FUNCTION_ALWAYS;
+	mip_sampler_params.max_anisotropy = 1;
+	kope_g5_device_create_sampler(&device, &mip_sampler_params, &mip_sampler);
+
 	for (int i = 0; i < 4; ++i) {
 		mip_parameters cparams = {0};
 		cparams.mip_source_texture.texture = &render_target;
 		cparams.mip_source_texture.base_mip_level = i;
 		cparams.mip_source_texture.mip_level_count = 1;
 		cparams.mip_source_texture.base_array_layer = 0;
 		cparams.mip_source_texture.array_layer_count = 1;
+
+		cparams.mip_source_sampler = &mip_sampler;
+
 		cparams.mip_destination_texture.texture = &render_target;
 		cparams.mip_destination_texture.base_mip_level = i + 1;
 		cparams.mip_destination_texture.mip_level_count = 1;
 		cparams.mip_destination_texture.base_array_layer = 0;
 		cparams.mip_destination_texture.array_layer_count = 1;
+
 		kong_create_mip_set(&device, &cparams, &mip_sets[i]);
 	}