Refactor shaders into seprate GLSL source files

The default implementation of QSGShaderMaterial::vertexShader() and
fragmentShader() now loads the GLSL source from a list of source files
that can be specified via the setShaderSourceFile() or
setShaderSourceFiles() functions.

Multiple shader source files for each shader stage are supported. Each
source file will be read in the order specified and concatenated
together before being compiled.

The other places where Qt Quick 2 loads shader source code have
been adapted to use the new QSGShaderSourceBuilder, which is also
used internally by QSGMaterial.

This puts Qt Quick 2 into a better state ready to support OpenGL
core profile and to load different shaders based upon OpenGL version,
profile, GPU vendor, platform, etc.

Change-Id: I1a66213c2ce788413168eb48c7bc5317e61988a2
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/src/quick/scenegraph/shaders/loqsubpixeldistancefieldtext.vert b/src/quick/scenegraph/shaders/loqsubpixeldistancefieldtext.vert
new file mode 100644
index 0000000000..33cb7efb19
--- /dev/null
+++ b/src/quick/scenegraph/shaders/loqsubpixeldistancefieldtext.vert
@@ -0,0 +1,27 @@
+uniform highp mat4 matrix;
+uniform highp vec2 textureScale;
+uniform highp float fontScale;
+uniform highp vec4 vecDelta;
+
+attribute highp vec4 vCoord;
+attribute highp vec2 tCoord;
+
+varying highp vec3 sampleNearLeft;
+varying highp vec3 sampleNearRight;
+
+void main()
+{
+    highp vec2 sampleCoord = tCoord * textureScale;
+    gl_Position = matrix * vCoord;
+
+    // Calculate neighbor pixel position in item space.
+    highp vec3 wDelta = gl_Position.w * vecDelta.xyw;
+    highp vec3 nearLeft = vCoord.xyw - 0.25 * wDelta;
+    highp vec3 nearRight = vCoord.xyw + 0.25 * wDelta;
+
+    // Calculate neighbor texture coordinate.
+    highp vec2 scale = textureScale / fontScale;
+    highp vec2 base = sampleCoord - scale * vCoord.xy;
+    sampleNearLeft = vec3(base * nearLeft.z + scale * nearLeft.xy, nearLeft.z);
+    sampleNearRight = vec3(base * nearRight.z + scale * nearRight.xy, nearRight.z);
+}
\ No newline at end of file