iOS: Fix multiple issues with PVRTC import, disable ETC1

Fixes: #28683, #28621, #28596 and maybe others

For iOS we enable pvrtc feature by default for both GLES2/GLES3
Etc1 for iOS doesn't have any sense, so it disabled.
Fixed checks in export editor.
Fixed pvrtc ability detection in GLES2 driver.
Fixed pvrtc encoding procedure.

drivers/gles2/rasterizer_storage_gles2.cpp

@@ -5898,7 +5898,7 @@ void RasterizerStorageGLES2::initialize() {
 	config.float_texture_supported = config.extensions.has("GL_ARB_texture_float") || config.extensions.has("GL_OES_texture_float");
 	config.s3tc_supported = config.extensions.has("GL_EXT_texture_compression_s3tc") || config.extensions.has("WEBGL_compressed_texture_s3tc");
 	config.etc1_supported = config.extensions.has("GL_OES_compressed_ETC1_RGB8_texture") || config.extensions.has("WEBGL_compressed_texture_etc1");
-	config.pvrtc_supported = config.extensions.has("IMG_texture_compression_pvrtc") || config.extensions.has("WEBGL_compressed_texture_pvrtc");
+	config.pvrtc_supported = config.extensions.has("GL_IMG_texture_compression_pvrtc") || config.extensions.has("WEBGL_compressed_texture_pvrtc");
 	config.support_npot_repeat_mipmap = config.extensions.has("GL_OES_texture_npot");
 
 #ifdef JAVASCRIPT_ENABLED

editor/editor_export.cpp

@@ -1298,6 +1298,30 @@ String EditorExportPlatform::test_etc2() const {
 	return String();
 }
 
+String EditorExportPlatform::test_etc2_or_pvrtc() const {
+
+	String driver = ProjectSettings::get_singleton()->get("rendering/quality/driver/driver_name");
+	bool driver_fallback = ProjectSettings::get_singleton()->get("rendering/quality/driver/fallback_to_gles2");
+	bool etc2_supported = ProjectSettings::get_singleton()->get("rendering/vram_compression/import_etc2");
+	bool pvrtc_supported = ProjectSettings::get_singleton()->get("rendering/vram_compression/import_pvrtc");
+
+	if (driver == "GLES2" && !pvrtc_supported) {
+		return TTR("Target platform requires 'PVRTC' texture compression for GLES2. Enable 'Import Pvrtc' in Project Settings.");
+	} else if (driver == "GLES3") {
+		String err;
+		if (!etc2_supported && !pvrtc_supported) {
+			err += TTR("Target platform requires 'ETC2' or 'PVRTC' texture compression for GLES3. Enable 'Import Etc 2' or 'Import Pvrtc' in Project Settings.");
+		}
+		if (driver_fallback && !pvrtc_supported) {
+			if (err != String())
+				err += "\n";
+			err += TTR("Target platform requires 'PVRTC' texture compression for the driver fallback to GLES2.\nEnable 'Import Pvrtc' in Project Settings, or disable 'Driver Fallback Enabled'.");
+		}
+		return err;
+	}
+	return String();
+}
+
 int EditorExport::get_export_preset_count() const {
 
 	return export_presets.size();

editor/editor_export.h

@@ -265,6 +265,7 @@ public:
 	virtual Ref<Texture> get_run_icon() const { return get_logo(); }
 
 	String test_etc2() const; //generic test for etc2 since most platforms use it
+	String test_etc2_or_pvrtc() const; // test for etc2 or pvrtc support for iOS
 	virtual bool can_export(const Ref<EditorExportPreset> &p_preset, String &r_error, bool &r_missing_templates) const = 0;
 
 	virtual List<String> get_binary_extensions(const Ref<EditorExportPreset> &p_preset) const = 0;

modules/pvr/texture_loader_pvr.cpp

@@ -215,10 +215,12 @@ static void _compress_pvrtc4(Image *p_img) {
 			int ofs, size, w, h;
 			img->get_mipmap_offset_size_and_dimensions(i, ofs, size, w, h);
 			Javelin::RgbaBitmap bm(w, h);
+			void *dst = (void *)bm.GetData();
+			copymem(dst, &r[ofs], size);
+			Javelin::ColorRgba<unsigned char> *dp = bm.GetData();
 			for (int j = 0; j < size / 4; j++) {
-				Javelin::ColorRgba<unsigned char> *dp = bm.GetData();
-				/* red and Green colors are swapped.  */
-				new (dp) Javelin::ColorRgba<unsigned char>(r[ofs + 4 * j + 2], r[ofs + 4 * j + 1], r[ofs + 4 * j], r[ofs + 4 * j + 3]);
+				/* red and blue colors are swapped.  */
+				SWAP(dp[j].r, dp[j].b);
 			}
 			new_img->get_mipmap_offset_size_and_dimensions(i, ofs, size, w, h);
 			Javelin::PvrTcEncoder::EncodeRgba4Bpp(&wr[ofs], bm);

platform/iphone/export/export.cpp

@@ -165,13 +165,9 @@ public:
 void EditorExportPlatformIOS::get_preset_features(const Ref<EditorExportPreset> &p_preset, List<String> *r_features) {
 
 	String driver = ProjectSettings::get_singleton()->get("rendering/quality/driver/driver_name");
-	if (driver == "GLES2") {
-		r_features->push_back("etc");
-	} else if (driver == "GLES3") {
+	r_features->push_back("pvrtc");
+	if (driver == "GLES3") {
 		r_features->push_back("etc2");
-		if (ProjectSettings::get_singleton()->get("rendering/quality/driver/fallback_to_gles2")) {
-			r_features->push_back("etc");
-		}
 	}
 
 	Vector<String> architectures = _get_preset_architectures(p_preset);
@@ -1515,7 +1511,7 @@ bool EditorExportPlatformIOS::can_export(const Ref<EditorExportPreset> &p_preset
 		}
 	}
 
-	String etc_error = test_etc2();
+	String etc_error = test_etc2_or_pvrtc();
 	if (etc_error != String()) {
 		valid = false;
 		err += etc_error;