feat(render): Renderer with LOD selection, 3.3 and 4.3+ upload paths, headless smoke test

include/plot/gl/api.hpp

@@ -59,6 +59,7 @@ enum : GLenum {
 
   // Pixel store state.
   GL_UNPACK_ALIGNMENT = 0x0CF5,
+  GL_PACK_ALIGNMENT = 0x0D05,
 
   // Shaders and programs.
   GL_FRAGMENT_SHADER = 0x8B30,
@@ -76,6 +77,9 @@ enum : GLenum {
   GL_MAP_PERSISTENT_BIT = 0x0040 /* 4.4 */,
   GL_MAP_COHERENT_BIT = 0x0080 /* 4.4 */,
 
+  // Rasterisation state (1.0).
+  GL_SCISSOR_TEST = 0x0C11,
+
   // Textures.
   GL_TEXTURE_2D = 0x0DE1,
   GL_TEXTURE0 = 0x84C0,
@@ -120,6 +124,8 @@ enum : GLenum {
   X(void, glEnable, (GLenum))                                                         \
   X(void, glBlendFunc, (GLenum, GLenum))                                              \
   X(void, glPixelStorei, (GLenum, GLint))                                             \
+  X(void, glDisable, (GLenum))                                                        \
+  X(void, glScissor, (GLint, GLint, GLsizei, GLsizei))                                \
   /* shaders and programs */                                                          \
   X(GLuint, glCreateShader, (GLenum))                                                 \
   X(void, glShaderSource, (GLuint, GLsizei, const GLchar* const*, const GLint*))      \
@@ -148,6 +154,8 @@ enum : GLenum {
   X(void, glBindBuffer, (GLenum, GLuint))                                             \
   X(void, glBufferData, (GLenum, GLsizeiptr, const void*, GLenum))                    \
   X(void, glBufferSubData, (GLenum, GLintptr, GLsizeiptr, const void*))               \
+  X(void*, glMapBufferRange, (GLenum, GLintptr, GLsizeiptr, GLbitfield))               \
+  X(GLboolean, glUnmapBuffer, (GLenum))                                               \
   /* vertex arrays */                                                                 \
   X(void, glGenVertexArrays, (GLsizei, GLuint*))                                      \
   X(void, glDeleteVertexArrays, (GLsizei, const GLuint*))                             \
@@ -182,8 +190,17 @@ enum : GLenum {
   X(GLenum, glClientWaitSync, (GLsync, GLbitfield, GLuint64))                         \
   X(void, glDeleteSync, (GLsync))
 
+// Entry points above the 3.3 baseline, resolved best-effort: a driver that lacks
+// one leaves it null and `load()` still succeeds, so the library keeps working on
+// a 3.3-only context. Every one of these is reached only after `caps()` -- or an
+// explicit null check -- says the context can do it (see caps.hpp).
+#define PLOT_GL_OPTIONAL_FUNCS(X)                                                     \
+  /* persistent buffer mapping, GL 4.4 / ARB_buffer_storage */                        \
+  X(void, glBufferStorage, (GLenum, GLsizeiptr, const void*, GLbitfield))
+
 #define PLOT_GL_DECL(ret, name, args) extern ret (*name) args;
 PLOT_GL_FUNCS(PLOT_GL_DECL)
+PLOT_GL_OPTIONAL_FUNCS(PLOT_GL_DECL)
 #undef PLOT_GL_DECL
 
 }  // namespace plot::gl