From 6bdee3fc1cdbe9a15cdb08160f8fbed52548b791 Mon Sep 17 00:00:00 2001
From: Gary Talent <gary@drinkingtea.net>
Date: Sat, 20 Mar 2021 15:47:32 -0500
Subject: [PATCH] [nostalgia/core/userland] Add texture deletion

---
 src/nostalgia/core/userland/gfx_opengl.cpp |  8 ++---
 src/nostalgia/core/userland/glutils.cpp    | 10 +++++--
 src/nostalgia/core/userland/glutils.hpp    | 34 ++++++++++------------
 3 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/src/nostalgia/core/userland/gfx_opengl.cpp b/src/nostalgia/core/userland/gfx_opengl.cpp
index 6cc0a1234..170811398 100644
--- a/src/nostalgia/core/userland/gfx_opengl.cpp
+++ b/src/nostalgia/core/userland/gfx_opengl.cpp
@@ -137,11 +137,11 @@ static void initBackgroundBufferset(Context *ctx, GLuint shader, Background *bg)
 }
 
 static ox::Error loadTexture(Texture *tex, void *pixels) {
-	if (tex->texId == 0) {
-		glGenTextures(1, &tex->texId);
+	if (tex->id == 0) {
+		glGenTextures(1, &tex->id);
 	}
 	glActiveTexture(GL_TEXTURE0);
-	glBindTexture(GL_TEXTURE_2D, tex->texId);
+	glBindTexture(GL_TEXTURE_2D, tex->id);
 	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tex->width, tex->height, 0,  GL_RGBA, GL_UNSIGNED_BYTE, pixels);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
@@ -258,7 +258,7 @@ void draw(Context *ctx) {
 
 void clearTileLayer(Context *ctx, int layer) {
 	const auto id = ctx->rendererData<renderer::GlImplData>();
-	auto bg = id->backgrounds[static_cast<std::size_t>(layer)];
+	auto &bg = id->backgrounds[static_cast<std::size_t>(layer)];
 	initBackgroundBufferObjects(ctx, &bg);
 	bg.updated = true;
 }
diff --git a/src/nostalgia/core/userland/glutils.cpp b/src/nostalgia/core/userland/glutils.cpp
index 134c5b91e..04b51c4ea 100644
--- a/src/nostalgia/core/userland/glutils.cpp
+++ b/src/nostalgia/core/userland/glutils.cpp
@@ -15,12 +15,17 @@
 
 namespace nostalgia::core::renderer {
 
+void deleteTexture(GLuint t) {
+	glDeleteTextures(1, &t);
+}
+
 template struct GLobject<glDeleteProgram>;
 template struct GLobject<glDeleteShader>;
+template struct GLobject<deleteTexture, TextureBase>;
 
 [[nodiscard]]
 static ox::Result<Shader> buildShader(GLuint shaderType, const GLchar *src, const char *shaderName) {
-	const auto shader = glCreateShader(shaderType);
+	Shader shader(glCreateShader(shaderType));
 	glShaderSource(shader, 1, &src, nullptr);
 	glCompileShader(shader);
 	GLint status;
@@ -29,10 +34,9 @@ static ox::Result<Shader> buildShader(GLuint shaderType, const GLchar *src, cons
 		std::array<char, 1000> errMsg;
 		glGetShaderInfoLog(shader, errMsg.size(), nullptr, errMsg.data());
 		oxErrorf("shader compile error in {}: {}", shaderName, errMsg.data());
-		glDeleteShader(shader);
 		return OxError(1, "shader compile error");
 	}
-	return Shader(shader);
+	return ox::move(shader);
 }
 
 [[nodiscard]]
diff --git a/src/nostalgia/core/userland/glutils.hpp b/src/nostalgia/core/userland/glutils.hpp
index 5f3384beb..3b2d19232 100644
--- a/src/nostalgia/core/userland/glutils.hpp
+++ b/src/nostalgia/core/userland/glutils.hpp
@@ -19,8 +19,18 @@
 
 namespace nostalgia::core::renderer {
 
-template<auto del>
-struct GLobject {
+struct Empty {};
+
+struct TextureBase {
+
+	GLsizei width = 0;
+	GLsizei height = 0;
+
+};
+
+
+template<auto del, typename Base = Empty>
+struct GLobject: public Base {
 
 	GLuint id = 0;
 
@@ -61,26 +71,14 @@ struct GLobject {
 
 };
 
+void deleteTexture(GLuint t);
+
 extern template struct GLobject<glDeleteProgram>;
 extern template struct GLobject<glDeleteShader>;
+extern template struct GLobject<deleteTexture, TextureBase>;
 using Shader = GLobject<glDeleteShader>;
 using Program = GLobject<glDeleteProgram>;
-
-struct Texture {
-
-	GLuint texId = 0;
-	GLsizei width = 0;
-	GLsizei height = 0;
-
-	constexpr operator GLuint&() noexcept {
-		return texId;
-	}
-
-	constexpr operator const GLuint&() const noexcept {
-		return texId;
-	}
-
-};
+using Texture = GLobject<deleteTexture, TextureBase>;
 
 struct Bufferset {
 	GLuint vao = 0;