@@ -27,6 +27,9 @@ constexpr auto frag_color = 0;

 int main()

 {

+    // Local data.

+    auto light_count = 3;

+

     // Global settings.

     Shader::root("assets/shaders");

     Shader::defines({

@@ -49,6 +52,7 @@ int main()

     // Use.

     player

         .use()

+        .uniform("light_count", light_count)

         .validate();

 }

 ```

@@ -257,6 +261,16 @@ value is of the wrong type. [`use`](#use) must be called before calling

 [uniform]: https://www.khronos.org/opengl/wiki/Uniform

+#### Scalar uniforms

+

+Template specializations are provided for all `GL*` types corresponding to a

+`glUniform1*` variant. As special cases, `GLboolean` and `bool` map to the `i`

+(`GLint`) variant. The `GLdouble` specialization is [`delete`][]d to avoid

+accidental conversions, change the type (with an `f`/`F` suffix in case of

+literals) or use an explicit cast to get the `GLfloat` specialization.

+

+[`delete`]: https://en.cppreference.com/w/cpp/language/function#Deleted_functions

+

 #### User-defined uniforms

 Support for e.g. third party mathematics libraries can be added by providing

@@ -267,8 +281,6 @@ the supplied variables `TYPE const & value` and `GLint const & location`,

 probably as parameters to `glUniform*`. `GLSHADER_UNIFORM_DELETE(TYPE)` can be

 used to [`delete`][] the specialization for a given type.

-[`delete`]: https://en.cppreference.com/w/cpp/language/function#Deleted_functions

-

 ## Dependencies

 Public (interface):

@@ -7,7 +7,10 @@

 #include "all_green.h"

+uniform float blue;

+

+

 void main()

 {

-    gl_FragColor = vec4(red, green, 0.25, 1.0);

+    gl_FragColor = vec4(red, green, blue, 1.0);

 }

new file mode 100644

@@ -0,0 +1,11 @@

+#version 110

+

+

+uniform float blue;

+

+

+void main()

+{

+    gl_FragColor = vec4(1.0, 0.5, blue, 1.0);

+}

+

@@ -155,4 +155,23 @@ inline Shader & Shader::use()

     }

+// Uniform scalar template specializations.

+

+#define GLSHADER_UNIFORM_SCALAR_(TYPE, SUFFIX) \

+    GLSHADER_UNIFORM( \

+        TYPE, \

+        glUniform1##SUFFIX( \

+            location, value \

+        ); \

+    )

+

+GLSHADER_UNIFORM_SCALAR_(bool,      i)

+GLSHADER_UNIFORM_SCALAR_(GLboolean, i)

+GLSHADER_UNIFORM_SCALAR_(GLint,     i)

+GLSHADER_UNIFORM_SCALAR_(GLuint,    ui)

+GLSHADER_UNIFORM_SCALAR_(GLfloat,   f)

+

+GLSHADER_UNIFORM_DELETE(GLdouble)

+

+

 #endif // GLSHADER_SHADER_HPP_

@@ -137,6 +137,30 @@ GLTEST(2, 0, 640, 480, glshader)

         "Failed to initialize vertex input 'vert_unset' of shader program 'tests/vert_unset.vert'."

     );

+    // Uniform scalars.

+    constexpr auto blue = 0.25F;

+    GLTEST_EXPECT_EXCEPTION(false,

+        Shader({"tests/uniform_blue.frag"}).uniform("noncurrent", 1.0F),

+        "Failed to set uniform 'noncurrent' of shader program 'tests/uniform_blue.frag'; "

+        "shader program not current."

+    )

+    GLTEST_EXPECT_EXCEPTION(false,

+        Shader({"tests/uniform_blue.frag"}).use().uniform("nonexistent", 1.0F),

+        "Failed to set uniform 'nonexistent' of shader program 'tests/uniform_blue.frag'; "

+        "uniform required but not found."

+    )

+    Shader({"tests/uniform_blue.frag"}).use().uniform("nonexistent", 1.0F, false);

+    GLTEST_EXPECT_EXCEPTION(false,

+        Shader({"tests/uniform_blue.frag"}).use().validate(),

+        "Failed to validate shader program 'tests/uniform_blue.frag'; "

+        "uniform 'blue' not set."

+    )

+    GLTEST_EXPECT_EXCEPTION(false,

+        Shader({"tests/uniform_blue.frag"}).use().uniform("blue", 1),

+        "Failed to set uniform 'blue' of shader program 'tests/uniform_blue.frag'; "

+        "got error GL_INVALID_OPERATION (wrong type?)."

+    )

+

     auto all = Shader({

         "tests/all.vert",

         "tests/all.frag",

@@ -144,6 +168,7 @@ GLTEST(2, 0, 640, 480, glshader)

     all

         .use()

+        .uniform("blue", blue)

         .validate();

     constexpr auto size = 0.5F;