From defa6574297e6b1d75f14a07ad993d239974c517 Mon Sep 17 00:00:00 2001
From: Bastien Bouclet <bastien.bouclet@gmail.com>
Date: Thu, 24 Dec 2015 18:37:18 +0100
Subject: [PATCH] STARK: Surfaces can be drawn with a B&W saturation effect

---
 engines/stark/gfx/openglssurface.cpp     | 3 +--
 engines/stark/gfx/surfacerenderer.cpp    | 7 ++++++-
 engines/stark/gfx/surfacerenderer.h      | 8 ++++++++
 engines/stark/shaders/stark_box.fragment | 7 ++-----
 4 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/engines/stark/gfx/openglssurface.cpp b/engines/stark/gfx/openglssurface.cpp
index 68c8a612da1..8ff6897f4f5 100644
--- a/engines/stark/gfx/openglssurface.cpp
+++ b/engines/stark/gfx/openglssurface.cpp
@@ -56,8 +56,7 @@ void OpenGLSSurfaceRenderer::render(const Texture *texture, const Common::Point
 	_gfx->start2DMode();
 
 	_shader->use();
-	_shader->setUniform("textured", true);
-	_shader->setUniform("color", Math::Vector4d(1.0f, 1.0f, 1.0f, 1.0f));
+	_shader->setUniform1f("fadeLevel", _fadeLevel);
 	_shader->setUniform("verOffsetXY", normalizeOriginalCoordinates(sLeft, sTop));
 	if (_noScalingOverride) {
 		_shader->setUniform("verSizeWH", normalizeCurrentCoordinates(sWidth, sHeight));
diff --git a/engines/stark/gfx/surfacerenderer.cpp b/engines/stark/gfx/surfacerenderer.cpp
index 5676366bffe..a0f5839ca0d 100644
--- a/engines/stark/gfx/surfacerenderer.cpp
+++ b/engines/stark/gfx/surfacerenderer.cpp
@@ -26,7 +26,8 @@ namespace Stark {
 namespace Gfx {
 
 SurfaceRenderer::SurfaceRenderer() :
-	_noScalingOverride(false) {
+	_noScalingOverride(false),
+	_fadeLevel(0) {
 
 }
 
@@ -38,5 +39,9 @@ void SurfaceRenderer::setNoScalingOverride(bool noScalingOverride) {
 	_noScalingOverride = noScalingOverride;
 }
 
+void SurfaceRenderer::setFadeLevel(float fadeLevel) {
+	_fadeLevel = fadeLevel;
+}
+
 } // End of namespace Gfx
 } // End of namespace Stark
diff --git a/engines/stark/gfx/surfacerenderer.h b/engines/stark/gfx/surfacerenderer.h
index 93860a75865..22a2ab3399c 100644
--- a/engines/stark/gfx/surfacerenderer.h
+++ b/engines/stark/gfx/surfacerenderer.h
@@ -51,8 +51,16 @@ public:
 	 */
 	void setNoScalingOverride(bool noScalingOverride);
 
+	/**
+	 * The fade level is added to the color value of each pixel
+	 *
+	 * It is a value between -1 and 1
+	 */
+	void setFadeLevel(float fadeLevel);
+
 protected:
 	bool _noScalingOverride;
+	float _fadeLevel;
 };
 
 } // End of namespace Gfx
diff --git a/engines/stark/shaders/stark_box.fragment b/engines/stark/shaders/stark_box.fragment
index 52e3e34a34f..1553f08d172 100644
--- a/engines/stark/shaders/stark_box.fragment
+++ b/engines/stark/shaders/stark_box.fragment
@@ -2,12 +2,9 @@ in vec2 Texcoord;
 
 OUTPUT
 
-uniform bool textured;
-uniform vec4 color;
+uniform float fadeLevel;
 uniform sampler2D tex;
 
 void main() {
-	outColor = color;
-	if (textured)
-		outColor = outColor * texture(tex, Texcoord);
+	outColor = texture(tex, Texcoord) + vec4(fadeLevel, fadeLevel, fadeLevel, 0);
 }