Add glDebugScope

Wrapper for glPushDebugGroup/glPopDebugGroup which allows neatly
grouping OpenGL calls in diagnostic tools.

8 files changed, 144 insertions, 46 deletions

diff --git a/gfx/gl/gldebug.cpp b/gfx/gl/gldebug.cpp
new file mode 100644
index 0000000..518d4fb
--- /dev/null
+++ b/gfx/gl/gldebug.cpp
@@ -0,0 +1,20 @@
+#if GLDEBUG == 2
+// Level 2 is out of line because its "complex"
+
+#	include "gldebug.h"
+#	include <format>
+
+glDebugScope::glDebugScope(GLuint id, const std::source_location & location)
+{
+	const auto fullMsg = std::format("{} ({}:{})", location.function_name(), location.file_name(), location.line());
+	glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, id, static_cast<GLsizei>(fullMsg.length()), fullMsg.c_str());
+}
+
+glDebugScope::glDebugScope(GLuint id, const std::string_view msg, const std::source_location & location)
+{
+	const auto fullMsg
+			= std::format("{} @ {} ({}:{})", msg, location.function_name(), location.file_name(), location.line());
+	glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, id, static_cast<GLsizei>(fullMsg.length()), fullMsg.c_str());
+}
+
+#endif
diff --git a/gfx/gl/gldebug.h b/gfx/gl/gldebug.h
new file mode 100644
index 0000000..5cfd099
--- /dev/null
+++ b/gfx/gl/gldebug.h
@@ -0,0 +1,52 @@
+#pragma once
+#ifndef GLDEBUG
+#	define GLDEBUG 0
+#endif
+
+#include "special_members.h"
+#include <glad/gl.h>
+#include <source_location>
+#include <string_view>
+
+class [[nodiscard]] glDebugScope {
+public:
+	explicit glDebugScope(GLuint id, const std::source_location & = std::source_location::current());
+	explicit glDebugScope(
+			GLuint id, std::string_view msg, const std::source_location & = std::source_location::current());
+
+	~glDebugScope();
+
+	constexpr
+	operator bool() const
+	{
+		return true;
+	}
+
+	NO_MOVE(glDebugScope);
+	NO_COPY(glDebugScope);
+};
+
+#if GLDEBUG > 0
+inline glDebugScope::~glDebugScope()
+{
+	glPopDebugGroup();
+}
+#	if GLDEBUG == 1
+// Level 1 is inlined for performance because they're thin wrappers
+inline glDebugScope::glDebugScope(GLuint id, const std::source_location & location) :
+	glDebugScope {id, location.function_name()}
+{
+}
+
+inline glDebugScope::glDebugScope(GLuint id, const std::string_view msg, const std::source_location &)
+{
+	glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, id, static_cast<GLsizei>(msg.length()), msg.data());
+}
+#	endif
+#else
+inline glDebugScope::glDebugScope(GLuint, const std::source_location &) { }
+
+inline glDebugScope::glDebugScope(GLuint, const std::string_view, const std::source_location &) { }
+
+inline glDebugScope::~glDebugScope() = default;
+#endif
diff --git a/gfx/gl/program.cpp b/gfx/gl/program.cpp
index fdd4c6f..da85456 100644
--- a/gfx/gl/program.cpp
+++ b/gfx/gl/program.cpp
@@ -1,5 +1,5 @@
 #include "program.h"
-#include "shader.h"
+#include "gldebug.h"
 #include <format>
 #include <glm/gtc/type_ptr.hpp>
 #include <glm/gtx/transform.hpp>
@@ -9,6 +9,7 @@
 void
 Program::linkAndValidate() const
 {
+	glDebugScope _ {m_program};
 	glLinkProgram(m_program);
 	checkProgramError(m_program, GL_LINK_STATUS, "Error linking shader program");
 
diff --git a/gfx/gl/program.h b/gfx/gl/program.h
index 20be1aa..2b06d2d 100644
--- a/gfx/gl/program.h
+++ b/gfx/gl/program.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "gldebug.h"
 #include "shader.h" // IWYU pragma: export
 #include <glRef.h>
 #include <glad/gl.h>
@@ -14,7 +15,9 @@ class Program {
 public:
 	Program() = delete;
 
-	template<typename... S> explicit Program(const S &... srcs)
+	template<typename... S> explicit Program(const S &... srcs) : Program {glDebugScope {0}, srcs...} { }
+
+	template<typename... S> explicit Program(glDebugScope, const S &... srcs)
 	{
 		(glAttachShader(m_program, srcs.compile()), ...);
 		linkAndValidate();
diff --git a/gfx/gl/sceneRenderer.cpp b/gfx/gl/sceneRenderer.cpp
index 9a4d153..65b4609 100644
--- a/gfx/gl/sceneRenderer.cpp
+++ b/gfx/gl/sceneRenderer.cpp
@@ -14,7 +14,9 @@ static constexpr const std::array<const glm::i8vec4, 4> displayVAOdata {{
 		{1, -1, 1, 0},
 }};
 
-SceneRenderer::SceneRenderer(ScreenAbsCoord s, GLuint o) :
+SceneRenderer::SceneRenderer(ScreenAbsCoord s, GLuint o) : SceneRenderer {s, o, glDebugScope {o}} { }
+
+SceneRenderer::SceneRenderer(ScreenAbsCoord s, GLuint o, glDebugScope) :
 	camera {{-1250000, -1250000, 35.0F}, quarter_pi, ratio(s), 100, 10000000}, size {s}, output {o},
 	lighting {lighting_vs, lighting_fs}, shadowMapper {{2048, 2048}}
 {
@@ -59,6 +61,7 @@ SceneRenderer::SceneRenderer(ScreenAbsCoord s, GLuint o) :
 void
 SceneRenderer::resize(ScreenAbsCoord newSize)
 {
+	glDebugScope _ {output};
 	size = newSize;
 	camera.setAspect(ratio(size));
 	const auto configuregdata = [this](const GLuint data, const GLint iformat, const GLenum format) {
@@ -77,55 +80,66 @@ SceneRenderer::resize(ScreenAbsCoord newSize)
 void
 SceneRenderer::render(const SceneProvider & scene) const
 {
+	glDebugScope _ {output};
 	shader.setViewProjection(camera.getPosition(), camera.getViewProjection());
 	glViewport(0, 0, size.x, size.y);
 
-	// Geometry/colour pass - writes albedo, normal and position textures
-	glBindFramebuffer(GL_FRAMEBUFFER, gBuffer);
-	glEnable(GL_BLEND);
-	glEnable(GL_CULL_FACE);
-	glCullFace(GL_BACK);
-	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-	glEnable(GL_DEPTH_TEST);
-	glClearColor(0, 0, 0, 1);
-	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-	scene.content(shader, camera);
-
-	// Environment pass -
-	// * ambient - clears illumination texture - see setAmbientLight
-	// * directional - updates shadowMapper, reads normal and position, writes illumination - see setDirectionalLight
-	scene.environment(shader, *this);
-
-	// Scene lights pass -
-	// * per light - reads normal and position, writes illumination
-	glBindFramebuffer(GL_FRAMEBUFFER, gBufferIll);
-	glBlendFunc(GL_ONE, GL_ONE);
-	glActiveTexture(GL_TEXTURE0);
-	glBindTexture(GL_TEXTURE_2D, gPosition);
-	glActiveTexture(GL_TEXTURE1);
-	glBindTexture(GL_TEXTURE_2D, gNormal);
-	glActiveTexture(GL_TEXTURE2);
-	glBindTexture(GL_TEXTURE_2D_ARRAY, shadowMapper);
-	glDisable(GL_DEPTH_TEST);
-	scene.lights(shader);
-
-	// Composition pass - reads albedo and illumination, writes output
-	glBindFramebuffer(GL_FRAMEBUFFER, output);
-	glViewport(0, 0, size.x, size.y);
-	glCullFace(GL_BACK);
-	glDisable(GL_BLEND);
-	glDisable(GL_DEPTH_TEST);
-	glActiveTexture(GL_TEXTURE2);
-	glBindTexture(GL_TEXTURE_2D, gAlbedoSpec);
-	glActiveTexture(GL_TEXTURE3);
-	glBindTexture(GL_TEXTURE_2D, gIllumination);
-	lighting.use();
-	renderQuad();
+	if (glDebugScope _ {gBuffer, "Geometry/colour pass"}) {
+		// Geometry/colour pass - writes albedo, normal and position textures
+		glBindFramebuffer(GL_FRAMEBUFFER, gBuffer);
+		glEnable(GL_BLEND);
+		glEnable(GL_CULL_FACE);
+		glCullFace(GL_BACK);
+		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+		glEnable(GL_DEPTH_TEST);
+		glClearColor(0, 0, 0, 1);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		scene.content(shader, camera);
+	}
+
+	if (glDebugScope _ {gBufferIll, "Environment pass"}) {
+		// Environment pass -
+		// * ambient - clears illumination texture - see setAmbientLight
+		// * directional - updates shadowMapper, reads normal and position, writes illumination - see
+		// setDirectionalLight
+		scene.environment(shader, *this);
+	}
+
+	if (glDebugScope _ {gBufferIll, "Scene lighting pass"}) {
+		// Scene lights pass -
+		// * per light - reads normal and position, writes illumination
+		glBindFramebuffer(GL_FRAMEBUFFER, gBufferIll);
+		glBlendFunc(GL_ONE, GL_ONE);
+		glActiveTexture(GL_TEXTURE0);
+		glBindTexture(GL_TEXTURE_2D, gPosition);
+		glActiveTexture(GL_TEXTURE1);
+		glBindTexture(GL_TEXTURE_2D, gNormal);
+		glActiveTexture(GL_TEXTURE2);
+		glBindTexture(GL_TEXTURE_2D_ARRAY, shadowMapper);
+		glDisable(GL_DEPTH_TEST);
+		scene.lights(shader);
+	}
+
+	if (glDebugScope _ {output, "Composition pass"}) {
+		// Composition pass - reads albedo and illumination, writes output
+		glBindFramebuffer(GL_FRAMEBUFFER, output);
+		glViewport(0, 0, size.x, size.y);
+		glCullFace(GL_BACK);
+		glDisable(GL_BLEND);
+		glDisable(GL_DEPTH_TEST);
+		glActiveTexture(GL_TEXTURE2);
+		glBindTexture(GL_TEXTURE_2D, gAlbedoSpec);
+		glActiveTexture(GL_TEXTURE3);
+		glBindTexture(GL_TEXTURE_2D, gIllumination);
+		lighting.use();
+		renderQuad();
+	}
 }
 
 void
 SceneRenderer::setAmbientLight(const RGB & colour) const
 {
+	glDebugScope _ {output};
 	glBindFramebuffer(GL_FRAMEBUFFER, gBufferIll);
 	glClearColor(colour.r, colour.g, colour.b, 1.0F);
 	glClear(GL_COLOR_BUFFER_BIT);
@@ -136,6 +150,7 @@ SceneRenderer::setDirectionalLight(
 		const RGB & colour, const LightDirection & direction, const SceneProvider & scene) const
 {
 	if (colour.r > 0 || colour.g > 0 || colour.b > 0) {
+		glDebugScope _ {output};
 		const auto lvp = shadowMapper.update(scene, direction, camera);
 		glBindFramebuffer(GL_FRAMEBUFFER, gBufferIll);
 		glBlendFunc(GL_ONE, GL_ONE);
diff --git a/gfx/gl/sceneRenderer.h b/gfx/gl/sceneRenderer.h
index 31f0cda..05921a1 100644
--- a/gfx/gl/sceneRenderer.h
+++ b/gfx/gl/sceneRenderer.h
@@ -2,6 +2,7 @@
 
 #include "gfx/lightDirection.h"
 #include "glArrays.h"
+#include "gldebug.h"
 #include "program.h"
 #include "sceneProvider.h"
 #include "sceneShader.h"
@@ -11,7 +12,8 @@
 
 class SceneRenderer {
 public:
-	explicit SceneRenderer(ScreenAbsCoord size, GLuint output);
+	SceneRenderer(ScreenAbsCoord size, GLuint output);
+	SceneRenderer(ScreenAbsCoord size, GLuint output, glDebugScope);
 
 	void resize(ScreenAbsCoord size);
 
diff --git a/gfx/gl/shadowMapper.cpp b/gfx/gl/shadowMapper.cpp
index 3cb73f7..486ba1c 100644
--- a/gfx/gl/shadowMapper.cpp
+++ b/gfx/gl/shadowMapper.cpp
@@ -16,6 +16,7 @@
 #include "gfx/lightDirection.h"
 #include "gfx/renderable.h"
 #include "gl_traits.h"
+#include "gldebug.h"
 #include "location.h"
 #include "maths.h"
 #include "sceneProvider.h"
@@ -32,6 +33,7 @@ ShadowMapper::ShadowMapper(const TextureAbsCoord & s) :
 			shadowDynamicPointInstWithTextures_fs},
 	size {s}
 {
+	glDebugScope _ {depthMap};
 	glBindTexture(GL_TEXTURE_2D_ARRAY, depthMap);
 	glTexImage3D(
 			GL_TEXTURE_2D_ARRAY, 0, GL_DEPTH_COMPONENT, size.x, size.y, 4, 0, GL_DEPTH_COMPONENT, GL_FLOAT, nullptr);
@@ -83,6 +85,7 @@ ShadowMapper::getBandViewExtents(const Camera & camera, const glm::mat4 & lightV
 ShadowMapper::Definitions
 ShadowMapper::update(const SceneProvider & scene, const LightDirection & dir, const Camera & camera) const
 {
+	glDebugScope _ {depthMap};
 	glCullFace(GL_FRONT);
 	glEnable(GL_DEPTH_TEST);
 
diff --git a/gfx/gl/shadowStenciller.cpp b/gfx/gl/shadowStenciller.cpp
index 86b77e4..a6124f5 100644
--- a/gfx/gl/shadowStenciller.cpp
+++ b/gfx/gl/shadowStenciller.cpp
@@ -1,5 +1,4 @@
 #include "shadowStenciller.h"
-#include "gfx/gl/program.h"
 #include "gfx/gl/shaders/fs-shadowStencil.h"
 #include "gfx/gl/shaders/gs-shadowStencil.h"
 #include "gfx/gl/shaders/vs-shadowStencil.h"
@@ -7,12 +6,14 @@
 #include "gfx/models/mesh.h"
 #include "glArrays.h"
 #include "gl_traits.h"
+#include "gldebug.h"
 #include "maths.h"
 #include <stdexcept>
 
 ShadowStenciller::ShadowStenciller() :
 	shadowCaster {shadowStencil_vs, shadowStencil_gs, shadowStencil_fs}, viewProjections {}
 {
+	glDebugScope _ {fbo};
 	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 	glDrawBuffer(GL_NONE);
 	glReadBuffer(GL_NONE);
@@ -50,6 +51,7 @@ ShadowStenciller::createStencilTexture(GLsizei width, GLsizei height)
 void
 ShadowStenciller::renderStencil(const glTexture & stencil, const MeshBase & mesh, const Texture::AnyPtr texture) const
 {
+	glDebugScope _ {fbo};
 	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 	glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, stencil, 0);
 	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {