Add core profile versions of the glyph cache shaders

The last step to make QOpenGLTextureGlyphCache working with
OpenGL core profiles.

[ChangeLog] Native (that is, not distance field based) text
rendering is now functional on OpenGL 3.2+ core profiles too.

Task-number: QTBUG-36993
Change-Id: Ic6c0db4806cea623ca7a19ab77b0329155824877
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

2 files changed, 40 insertions, 4 deletions

diff --git a/src/gui/opengl/qopenglengineshadersource_p.h b/src/gui/opengl/qopenglengineshadersource_p.h
index 5bb0bc4704..02a23193a8 100644
--- a/src/gui/opengl/qopenglengineshadersource_p.h
+++ b/src/gui/opengl/qopenglengineshadersource_p.h
@@ -517,6 +517,41 @@ static const char* const qopenglslRgbMaskFragmentShaderPass2 = "\n\
         ExclusionCompositionModeFragmentShader,
 */
 
+// OpenGL 3.2 core profile versions of shaders that are used by QOpenGLTextureGlyphCache
+
+static const char* const qopenglslMainWithTexCoordsVertexShader_core = "#version 150 core \n\
+        in vec2 textureCoordArray; \n\
+        out vec2 textureCoords; \n\
+        void setPosition(); \n\
+        void main(void) \n\
+        { \n\
+            setPosition(); \n\
+            textureCoords = textureCoordArray; \n\
+        }\n";
+
+static const char* const qopenglslUntransformedPositionVertexShader_core = "\n\
+        in vec4 vertexCoordsArray; \n\
+        void setPosition(void) \n\
+        { \n\
+            gl_Position = vertexCoordsArray; \n\
+        }\n";
+
+static const char* const qopenglslMainFragmentShader_core = "#version 150 core \n\
+        vec4 srcPixel(); \n\
+        out vec4 fragColor; \n\
+        void main() \n\
+        { \n\
+            fragColor = srcPixel(); \n\
+        }\n";
+
+static const char* const qopenglslImageSrcFragmentShader_core = "\n\
+        in vec2 textureCoords; \n\
+        uniform sampler2D imageTexture; \n\
+        vec4 srcPixel() \n\
+        { \n"
+             "return texture(imageTexture, textureCoords); \n"
+        "}\n";
+
 QT_END_NAMESPACE
 
 #endif // GLGC_SHADER_SOURCE_H
diff --git a/src/gui/opengl/qopengltextureglyphcache.cpp b/src/gui/opengl/qopengltextureglyphcache.cpp
index 3524c1cb1a..356f68b49b 100644
--- a/src/gui/opengl/qopengltextureglyphcache.cpp
+++ b/src/gui/opengl/qopengltextureglyphcache.cpp
@@ -248,11 +248,12 @@ void QOpenGLTextureGlyphCache::resizeTextureData(int width, int height)
     if (pex == 0) {
         if (m_blitProgram == 0) {
             m_blitProgram = new QOpenGLShaderProgram(ctx);
+            const bool isCoreProfile = ctx->format().profile() == QSurfaceFormat::CoreProfile;
 
             {
                 QString source;
-                source.append(QLatin1String(qopenglslMainWithTexCoordsVertexShader));
-                source.append(QLatin1String(qopenglslUntransformedPositionVertexShader));
+                source.append(QLatin1String(isCoreProfile ? qopenglslMainWithTexCoordsVertexShader_core : qopenglslMainWithTexCoordsVertexShader));
+                source.append(QLatin1String(isCoreProfile ? qopenglslUntransformedPositionVertexShader_core : qopenglslUntransformedPositionVertexShader));
 
                 QOpenGLShader *vertexShader = new QOpenGLShader(QOpenGLShader::Vertex, m_blitProgram);
                 vertexShader->compileSourceCode(source);
@@ -262,8 +263,8 @@ void QOpenGLTextureGlyphCache::resizeTextureData(int width, int height)
 
             {
                 QString source;
-                source.append(QLatin1String(qopenglslMainFragmentShader));
-                source.append(QLatin1String(qopenglslImageSrcFragmentShader));
+                source.append(QLatin1String(isCoreProfile ? qopenglslMainFragmentShader_core : qopenglslMainFragmentShader));
+                source.append(QLatin1String(isCoreProfile ? qopenglslImageSrcFragmentShader_core : qopenglslImageSrcFragmentShader));
 
                 QOpenGLShader *fragmentShader = new QOpenGLShader(QOpenGLShader::Fragment, m_blitProgram);
                 fragmentShader->compileSourceCode(source);