From 8f6a6ac8d0a47b07f5bb283d4965bcd208a5b05c Mon Sep 17 00:00:00 2001
From: Theogen Ratkin <feogenratkin@gmail.com>
Date: Thu, 17 Dec 2020 11:46:34 -0400
Subject: [PATCH] Add interpolation parameter to resize_to_po2()

Image::resize_to_po2() now takes an optional p_interpolation parameter
that it passes directly to resize() with default value INTERPOLATE_BILINEAR.

GLES2: call resize_to_po2() with interpolate argument

Call resize_to_po2() in GLES2 rasterizer storage with either
INTERPOLATE_BILINEAR or INTERPOLATE_NEAREST depending on TEXTURE_FLAG_FILTER.

This avoids filtering issues with non power of two pixel art textures.
See #44379
---
 core/image.cpp                             | 6 +++---
 core/image.h                               | 2 +-
 doc/classes/Image.xml                      | 6 ++++--
 drivers/gles2/rasterizer_storage_gles2.cpp | 2 +-
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/core/image.cpp b/core/image.cpp
index 674c3e99767..d47de1b3e8c 100644
--- a/core/image.cpp
+++ b/core/image.cpp
@@ -867,7 +867,7 @@ bool Image::is_size_po2() const {
 	return uint32_t(width) == next_power_of_2(width) && uint32_t(height) == next_power_of_2(height);
 }
 
-void Image::resize_to_po2(bool p_square) {
+void Image::resize_to_po2(bool p_square, Interpolation p_interpolation) {
 
 	ERR_FAIL_COND_MSG(!_can_modify(format), "Cannot resize in compressed or custom image formats.");
 
@@ -883,7 +883,7 @@ void Image::resize_to_po2(bool p_square) {
 			return; //nothing to do
 	}
 
-	resize(w, h);
+	resize(w, h, p_interpolation);
 }
 
 void Image::resize(int p_width, int p_height, Interpolation p_interpolation) {
@@ -2725,7 +2725,7 @@ void Image::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("get_mipmap_offset", "mipmap"), &Image::get_mipmap_offset);
 
-	ClassDB::bind_method(D_METHOD("resize_to_po2", "square"), &Image::resize_to_po2, DEFVAL(false));
+	ClassDB::bind_method(D_METHOD("resize_to_po2", "square", "interpolation"), &Image::resize_to_po2, DEFVAL(false), DEFVAL(INTERPOLATE_BILINEAR));
 	ClassDB::bind_method(D_METHOD("resize", "width", "height", "interpolation"), &Image::resize, DEFVAL(INTERPOLATE_BILINEAR));
 	ClassDB::bind_method(D_METHOD("shrink_x2"), &Image::shrink_x2);
 	ClassDB::bind_method(D_METHOD("expand_x2_hq2x"), &Image::expand_x2_hq2x);
diff --git a/core/image.h b/core/image.h
index 2fff89bc6e2..327efc4c62b 100644
--- a/core/image.h
+++ b/core/image.h
@@ -225,7 +225,7 @@ public:
 	/**
 	 * Resize the image, using the preferred interpolation method.
 	 */
-	void resize_to_po2(bool p_square = false);
+	void resize_to_po2(bool p_square = false, Interpolation p_interpolation = INTERPOLATE_BILINEAR);
 	void resize(int p_width, int p_height, Interpolation p_interpolation = INTERPOLATE_BILINEAR);
 	void shrink_x2();
 	void expand_x2_hq2x();
diff --git a/doc/classes/Image.xml b/doc/classes/Image.xml
index 7b32e6eb9b6..9340b3f94cb 100644
--- a/doc/classes/Image.xml
+++ b/doc/classes/Image.xml
@@ -414,7 +414,7 @@
 			<argument index="2" name="interpolation" type="int" enum="Image.Interpolation" default="1">
 			</argument>
 			<description>
-				Resizes the image to the given [code]width[/code] and [code]height[/code]. New pixels are calculated using [code]interpolation[/code]. See [code]interpolation[/code] constants.
+				Resizes the image to the given [code]width[/code] and [code]height[/code]. New pixels are calculated using the [code]interpolation[/code] mode defined via [enum Interpolation] constants.
 			</description>
 		</method>
 		<method name="resize_to_po2">
@@ -422,8 +422,10 @@
 			</return>
 			<argument index="0" name="square" type="bool" default="false">
 			</argument>
+			<argument index="1" name="interpolation" type="int" enum="Image.Interpolation" default="1">
+			</argument>
 			<description>
-				Resizes the image to the nearest power of 2 for the width and height. If [code]square[/code] is [code]true[/code] then set width and height to be the same.
+				Resizes the image to the nearest power of 2 for the width and height. If [code]square[/code] is [code]true[/code] then set width and height to be the same. New pixels are calculated using the [code]interpolation[/code] mode defined via [enum Interpolation] constants.
 			</description>
 		</method>
 		<method name="rgbe_to_srgb">
diff --git a/drivers/gles2/rasterizer_storage_gles2.cpp b/drivers/gles2/rasterizer_storage_gles2.cpp
index 322f63488cb..86e9db66a04 100644
--- a/drivers/gles2/rasterizer_storage_gles2.cpp
+++ b/drivers/gles2/rasterizer_storage_gles2.cpp
@@ -682,7 +682,7 @@ void RasterizerStorageGLES2::texture_set_data(RID p_texture, const Ref<Image> &p
 		if (img == p_image) {
 			img = img->duplicate();
 		}
-		img->resize_to_po2(false);
+		img->resize_to_po2(false, texture->flags & VS::TEXTURE_FLAG_FILTER ? Image::INTERPOLATE_BILINEAR : Image::INTERPOLATE_NEAREST);
 	}
 
 	if (config.shrink_textures_x2 && (p_image->has_mipmaps() || !p_image->is_compressed()) && !(texture->flags & VS::TEXTURE_FLAG_USED_FOR_STREAMING)) {