feat(render): style, GLSL line/text pipelines, staging batches, bitmap font

include/plot/gl/api.hpp

@@ -139,6 +139,7 @@ enum : GLenum {
   X(void, glUniform1i, (GLint, GLint))                                                \
   X(void, glUniform1f, (GLint, float))                                                \
   X(void, glUniform2f, (GLint, float, float))                                         \
+  X(void, glUniform4f, (GLint, float, float, float, float))                           \
   X(void, glUniform1fv, (GLint, GLsizei, const float*))                               \
   X(void, glUniform2fv, (GLint, GLsizei, const float*))                               \
   /* buffers */                                                                       \
@@ -153,6 +154,7 @@ enum : GLenum {
   X(void, glBindVertexArray, (GLuint))                                                \
   X(void, glEnableVertexAttribArray, (GLuint))                                        \
   X(void, glVertexAttribPointer, (GLuint, GLint, GLenum, GLboolean, GLsizei, const void*)) \
+  X(void, glVertexAttribDivisor, (GLuint, GLuint))                                    \
   /* drawing */                                                                       \
   X(void, glDrawArrays, (GLenum, GLint, GLsizei))                                     \
   X(void, glDrawArraysInstanced, (GLenum, GLint, GLsizei, GLsizei))                   \

include/plot/gl/handle.hpp

@@ -1,4 +1,5 @@
 #pragma once
+#include <plot/core/color.hpp>
 #include <plot/core/status.hpp>
 #include <plot/core/types.hpp>
 #include <plot/gl/api.hpp>
@@ -103,6 +104,13 @@ class Program final : public Handle<Program> {
 
   /// Sets a two-component float uniform.
   void set_uniform(const char* name, Vec2 value) const noexcept;
+  /// Sets a four-component float uniform, e.g. the colour of a pipeline.
+  void set_uniform(const char* name, Color value) const noexcept;
+
+  /// Sets an integer uniform, e.g. a sampler's texture unit. Deliberately not
+  /// an overload of the float setter: an untyped literal such as `0` must not
+  /// turn a float uniform into a `glUniform1i` call.
+  void set_uniform_int(const char* name, i32 value) const noexcept;
 
   /// Exposed for the CRTP base.
   static void destroy(GLuint id) noexcept;