[Feat] (...): Add BufferState and VertexBufferState while implementing these gl functions.

MG/MG_GL/State/VertexArray/VertexArrayState.cpp

@@ -0,0 +1,91 @@
+//
+// Created by BZLZHH on 2025/5/1.
+//
+
+// TODO: Add more gl error check for buffer state manager.
+
+#include "VertexArrayState.h"
+
+VertexArrayState::VertexArrayState() {
+    vaos_[0];
+}
+
+GLenum VertexArrayState::Create(GLuint* array) {
+    if (array == nullptr) return GL_INVALID_VALUE;
+
+    GLuint id = freeIds_.empty() ? ++lastId_ : *freeIds_.begin();
+    if (!freeIds_.empty()) {
+        freeIds_.erase(freeIds_.begin());
+    }
+
+    *array = id;
+    vaos_[id].generated = true;
+    return GL_NO_ERROR;
+}
+
+GLenum VertexArrayState::CreateN(GLsizei n, GLuint* arrays) {
+    if (n < 0) {
+        return GL_INVALID_VALUE; 
+    }
+
+    if (n > 0 && arrays == nullptr) {
+        return GL_INVALID_VALUE;
+    }
+
+    for (GLsizei i = 0; i < n; ++i) {
+        if (GLenum error = Create(&arrays[i]); error != GL_NO_ERROR) {
+            return error;
+        }
+    }
+    return GL_NO_ERROR;
+}
+
+GLenum VertexArrayState::Bind(GLuint array) {
+    if (array != 0 && !vaos_.count(array)) return GL_INVALID_OPERATION;
+    currentVao_ = array;
+    return GL_NO_ERROR;
+}
+
+GLenum VertexArrayState::EnableAttrib(GLuint index) {
+    if (currentVao_ == 0) return GL_INVALID_OPERATION;
+    if (index >= GL_MAX_VERTEX_ATTRIBS) return GL_INVALID_VALUE;
+    vaos_[currentVao_].attribs[index].enabled = true;
+    return GL_NO_ERROR;
+}
+
+GLenum VertexArrayState::DisableAttrib(GLuint index) {
+    if (currentVao_ == 0) return GL_INVALID_OPERATION;
+    if (index >= GL_MAX_VERTEX_ATTRIBS) return GL_INVALID_VALUE;
+    vaos_[currentVao_].attribs[index].enabled = false;
+    return GL_NO_ERROR;
+}
+
+GLenum VertexArrayState::SetAttribPointer(GLuint index, GLint size, GLenum type,
+                                          GLboolean normalized, GLsizei stride,
+                                          const void* pointer, bool isInteger,
+                                          GLuint currentArrayBuffer) {
+    if (currentVao_ == 0) return GL_INVALID_OPERATION;
+    if (index >= GL_MAX_VERTEX_ATTRIBS) return GL_INVALID_VALUE;
+
+    VertexAttribState state;
+    state.size = size;
+    state.type = type;
+    state.normalized = normalized;
+    state.stride = stride;
+    state.pointer = pointer;
+    state.buffer = currentArrayBuffer;
+    state.isInteger = isInteger;
+
+    vaos_[currentVao_].attribs[index] = state;
+    return GL_NO_ERROR;
+}
+
+GLuint VertexArrayState::GetBoundElementBuffer() {
+    auto it = vaos_.find(currentVao_);
+    return (it != vaos_.end()) ? it->second.elementBuffer : 0;
+}
+
+VertexArrayObject* VertexArrayState::GetCurrentVAO() {
+    auto it = vaos_.find(currentVao_);
+    return (it != vaos_.end()) ? &it->second : &vaos_.at(0);
+}