Image: Add a method for detecting signed values

core/io/image.cpp

@@ -3824,6 +3824,33 @@ void Image::bump_map_to_normal_map(float bump_scale) {
 	data = result_image;
 }
 
+bool Image::detect_signed(bool p_include_mips) const {
+	ERR_FAIL_COND_V(is_compressed(), false);
+
+	if (format >= Image::FORMAT_RH && format <= Image::FORMAT_RGBAH) {
+		const uint16_t *img_data = reinterpret_cast<const uint16_t *>(data.ptr());
+		const uint64_t img_size = p_include_mips ? (data.size() / 2) : (width * height * get_format_pixel_size(format) / 2);
+
+		for (uint64_t i = 0; i < img_size; i++) {
+			if ((img_data[i] & 0x8000) != 0 && (img_data[i] & 0x7fff) != 0) {
+				return true;
+			}
+		}
+
+	} else if (format >= Image::FORMAT_RF && format <= Image::FORMAT_RGBAF) {
+		const uint32_t *img_data = reinterpret_cast<const uint32_t *>(data.ptr());
+		const uint64_t img_size = p_include_mips ? (data.size() / 4) : (width * height * get_format_pixel_size(format) / 4);
+
+		for (uint64_t i = 0; i < img_size; i++) {
+			if ((img_data[i] & 0x80000000) != 0 && (img_data[i] & 0x7fffffff) != 0) {
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
+
 void Image::srgb_to_linear() {
 	if (data.size() == 0) {
 		return;

core/io/image.h

@@ -391,6 +391,8 @@ public:
 	Ref<Image> get_image_from_mipmap(int p_mipmap) const;
 	void bump_map_to_normal_map(float bump_scale = 1.0);
 
+	bool detect_signed(bool p_include_mips = true) const;
+
 	void blit_rect(const Ref<Image> &p_src, const Rect2i &p_src_rect, const Point2i &p_dest);
 	void blit_rect_mask(const Ref<Image> &p_src, const Ref<Image> &p_mask, const Rect2i &p_src_rect, const Point2i &p_dest);
 	void blend_rect(const Ref<Image> &p_src, const Rect2i &p_src_rect, const Point2i &p_dest);

modules/betsy/image_compress_betsy.cpp

@@ -49,31 +49,6 @@ static int get_next_multiple(int n, int m) {
 	return n + (m - (n % m));
 }
 
-static bool is_image_signed(const Image *r_img) {
-	if (r_img->get_format() >= Image::FORMAT_RH && r_img->get_format() <= Image::FORMAT_RGBAH) {
-		const uint16_t *img_data = reinterpret_cast<const uint16_t *>(r_img->ptr());
-		const uint64_t img_size = r_img->get_data_size() / 2;
-
-		for (uint64_t i = 0; i < img_size; i++) {
-			if ((img_data[i] & 0x8000) != 0 && (img_data[i] & 0x7fff) != 0) {
-				return true;
-			}
-		}
-
-	} else if (r_img->get_format() >= Image::FORMAT_RF && r_img->get_format() <= Image::FORMAT_RGBAF) {
-		const uint32_t *img_data = reinterpret_cast<const uint32_t *>(r_img->ptr());
-		const uint64_t img_size = r_img->get_data_size() / 4;
-
-		for (uint64_t i = 0; i < img_size; i++) {
-			if ((img_data[i] & 0x80000000) != 0 && (img_data[i] & 0x7fffffff) != 0) {
-				return true;
-			}
-		}
-	}
-
-	return false;
-}
-
 Error _compress_betsy(BetsyFormat p_format, Image *r_img) {
 	uint64_t start_time = OS::get_singleton()->get_ticks_msec();
 
@@ -125,7 +100,7 @@ Error _compress_betsy(BetsyFormat p_format, Image *r_img) {
 		case BETSY_FORMAT_BC6: {
 			err = compute_shader->parse_versions_from_text(bc6h_shader_glsl);
 
-			if (is_image_signed(r_img)) {
+			if (r_img->detect_signed(true)) {
 				dest_format = Image::FORMAT_BPTC_RGBF;
 				version = "signed";
 			} else {

modules/cvtt/image_compress_cvtt.cpp

@@ -174,17 +174,7 @@ void image_compress_cvtt(Image *p_image, Image::UsedChannels p_channels) {
 			p_image->convert(Image::FORMAT_RGBH);
 		}
 
-		const uint8_t *rb = p_image->get_data().ptr();
+		is_signed = p_image->detect_signed();
-
-		const uint16_t *source_data = reinterpret_cast<const uint16_t *>(&rb[0]);
-		int pixel_element_count = w * h * 3;
-		for (int i = 0; i < pixel_element_count; i++) {
-			if ((source_data[i] & 0x8000) != 0 && (source_data[i] & 0x7fff) != 0) {
-				is_signed = true;
-				break;
-			}
-		}
-
 		target_format = is_signed ? Image::FORMAT_BPTC_RGBF : Image::FORMAT_BPTC_RGBFU;
 	} else {
 		p_image->convert(Image::FORMAT_RGBA8); //still uses RGBA to convert