Image: Add a method for detecting signed values

godotengine · Jun 5, 2024 · 34ecaaf · 34ecaaf
1 parent 3ac9843
commit 34ecaaf
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Showing 3 changed files with 30 additions and 11 deletions.
diff --git a/core/io/image.cpp b/core/io/image.cpp
@@ -3710,6 +3710,33 @@ 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;

diff --git a/core/io/image.h b/core/io/image.h
@@ -386,6 +386,8 @@ class Image : public Resource {
 	Ref<Image> get_image_from_mipmap(int p_mipamp) 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);

diff --git a/modules/cvtt/image_compress_cvtt.cpp b/modules/cvtt/image_compress_cvtt.cpp
@@ -171,17 +171,7 @@ 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();
-
-		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;
-			}
-		}
-
+		is_signed = p_image->detect_signed();
 		target_format = is_signed ? Image::FORMAT_BPTC_RGBF : Image::FORMAT_BPTC_RGBFU;
 	} else {
 		p_image->convert(Image::FORMAT_RGBA8); //still uses RGBA to convert