Remove forceAlpha uniform, which is no longer needed

This was originally added by d467fc1bdbcf69bd6ef213bd909633c2edfb6878,
to prevent alpha ending up to be 0 with blending disabled. Apparently,
that was a driver issue that is no longer present.

REVIEW: 107090

effects/logout/logout.cpp

@@ -387,7 +387,6 @@ void LogoutEffect::renderBlurTexture()
     m_blurShader->setUniform(GLShader::Offset, QVector2D(0, 0));
     m_blurShader->setUniform(GLShader::ModulationConstant, QVector4D(1.0, 1.0, 1.0, 1.0));
     m_blurShader->setUniform(GLShader::Saturation, 1.0);
-    m_blurShader->setUniform(GLShader::AlphaToOne, 1);
     m_blurShader->setUniform("u_alphaProgress", (float)progress * 0.4f);
     glEnable(GL_BLEND);
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

effects/trackmouse/trackmouse.cpp

@@ -143,7 +143,6 @@ void TrackMouseEffect::paintScreen(int mask, QRegion region, ScreenPaintData& da
                 shader->setUniform(GLShader::ModelViewMatrix, matrix);
                 shader->setUniform(GLShader::Saturation, 1.0);
                 shader->setUniform(GLShader::ModulationConstant, QVector4D(1.0, 1.0, 1.0, 1.0));
-                shader->setUniform(GLShader::AlphaToOne, 0);
             } else
                 pushMatrix(matrix);
             m_texture[i]->bind();

lanczosfilter.cpp

@@ -215,7 +215,6 @@ void LanczosFilter::performPaint(EffectWindowImpl* w, int mask, QRegion region,
                         shader->setUniform(GLShader::Offset, QVector2D(0, 0));
                         shader->setUniform(GLShader::ModulationConstant, QVector4D(rgb, rgb, rgb, a));
                         shader->setUniform(GLShader::Saturation, data.saturation());
-                        shader->setUniform(GLShader::AlphaToOne, 0);
 
                         cachedTexture->render(region, textureRect, hardwareClipping);
 
@@ -352,7 +351,6 @@ void LanczosFilter::performPaint(EffectWindowImpl* w, int mask, QRegion region,
                 shader->setUniform(GLShader::Offset, QVector2D(0, 0));
                 shader->setUniform(GLShader::ModulationConstant, QVector4D(rgb, rgb, rgb, a));
                 shader->setUniform(GLShader::Saturation, data.saturation());
-                shader->setUniform(GLShader::AlphaToOne, 0);
 
                 cache->render(region, textureRect, hardwareClipping);
 

libkwineffects/kwinglutils.cpp

@@ -430,8 +430,6 @@ void GLShader::resolveLocations()
 
     mFloatLocation[Saturation]    = uniformLocation("saturation");
 
-    mIntLocation[AlphaToOne] = uniformLocation("u_forceAlpha");
-
     mLocationsResolved = true;
 }
 
@@ -895,7 +893,6 @@ void ShaderManager::resetShader(ShaderType type)
     shader->setUniform(GLShader::ModulationConstant, QVector4D(1.0, 1.0, 1.0, 1.0));
 
     shader->setUniform(GLShader::Saturation, 1.0f);
-    shader->setUniform(GLShader::AlphaToOne, 0);
 }
 
 /***  GLRenderTarget  ***/

libkwineffects/kwinglutils.h

@@ -190,7 +190,7 @@ public:
     };
 
     enum IntUniform {
-        AlphaToOne,
+        AlphaToOne,     ///< @deprecated no longer used
         IntUniformCount
     };
 
@@ -247,9 +247,6 @@ public:
          * normalized texture coordinates. Defaults to @c (1.0/1.0). And expects a @c vec3
          * uniform @c colorManiuplation, with @c x being opacity, @c y being brightness and
          * @c z being saturation. All three values default to @c 1.0.
-         * The fragment shader takes a uniform @c u_forceAlpha to force the alpha component
-         * to @c 1.0 if it is set to a value not @c 0. This uniform is useful when rendering
-         * a RGB-only window and the alpha channel is required in a later step.
          * The sampler uniform is @c sample and defaults to @c 0.
          * The shader uses two vertex attributes @c vertex and @c texCoord.
          **/

scene-fragment.glsl

@@ -1,7 +1,6 @@
 uniform sampler2D sampler;
 uniform vec4 modulation;
 uniform float saturation;
-uniform int u_forceAlpha;
 
 varying vec2 varyingTexCoords;
 
@@ -10,8 +9,6 @@ varying vec2 varyingTexCoords;
 void main() {
     vec4 tex = texture2D(sampler, varyingTexCoords);
 
-    tex.a += float(u_forceAlpha);
-
     if (saturation != 1.0) {
         tex.rgb = mix(vec3(dot( vec3( 0.30, 0.59, 0.11 ), tex.rgb )), tex.rgb, saturation);
     }

scene_opengl.cpp

@@ -1256,7 +1256,6 @@ void SceneOpenGL2Window::prepareStates(TextureType type, qreal opacity, qreal br
     GLShader *shader = ShaderManager::instance()->getBoundShader();
     shader->setUniform(GLShader::ModulationConstant, QVector4D(rgb, rgb, rgb, a));
     shader->setUniform(GLShader::Saturation,         saturation);
-    shader->setUniform(GLShader::AlphaToOne,         opaque ? 1 : 0);
 }
 
 void SceneOpenGL2Window::restoreStates(TextureType type, qreal opacity, qreal brightness, qreal saturation)
@@ -1269,7 +1268,6 @@ void SceneOpenGL2Window::restoreStates(TextureType type, qreal opacity, qreal br
     if (m_blendingEnabled) {
         glDisable(GL_BLEND);
     }
-    ShaderManager::instance()->getBoundShader()->setUniform(GLShader::AlphaToOne, 0);
 }
 
 //***************************************
@@ -1561,7 +1559,6 @@ void SceneOpenGL::EffectFrame::render(QRegion region, double opacity, double fra
 
         shader->setUniform(GLShader::ModulationConstant, QVector4D(1.0, 1.0, 1.0, 1.0));
         shader->setUniform(GLShader::Saturation, 1.0f);
-        shader->setUniform(GLShader::AlphaToOne, 0);
     }
 
     glEnable(GL_BLEND);