[Feat] (...): Add FramebufferState while implementing these gl functions.

2026-09-08 04:08:32 +09:00 · 2025-05-04 01:17:09 +08:00
parent 03c9531e7a
commit 30beaf6eb9
11 changed files with 337 additions and 6 deletions
@@ -0,0 +1,163 @@
+//
+// Created by BZLZHH on 2025/5/3.
+//
+
+// TODO: Add more gl error check for framebuffer state manager.
+// TODO: Check if the state machine really meets up to OpenGL 3 standard.
+
+#include "FramebufferState.h"
+
+// Re-Include Includes.h, cuz of the absence of GLState.h
+#undef MOBILEGL_GLSTATE_H
+#include "../../../Includes.h"
+
+GLenum FramebufferState::Create(GLuint* framebuffer) {
+    if (!framebuffer) return GL_INVALID_VALUE;
+    GLuint id = freeIds_.empty() ? ++lastId_ : *freeIds_.begin();
+    if (!freeIds_.empty()) freeIds_.erase(freeIds_.begin());
+    *framebuffer = id;
+    framebuffers_[id].generated = true;
+    return GL_NO_ERROR;
+}
+
+GLenum FramebufferState::CreateN(GLsizei n, GLuint* framebuffers) {
+    if (n < 0) return GL_INVALID_VALUE;
+    for (GLsizei i = 0; i < n; ++i) {
+        if (GLenum err = Create(&framebuffers[i])) return err;
+    }
+    return GL_NO_ERROR;
+}
+
+GLenum FramebufferState::Delete(GLuint framebuffer) {
+    if (framebuffer == 0) return GL_INVALID_VALUE;
+    
+    if (framebuffers_.erase(framebuffer)) {
+        freeIds_.insert(framebuffer);
+        for (auto& [target, id] : currentBindings_) {
+            if (id == framebuffer) id = 0;
+        }
+    }
+    return GL_NO_ERROR;
+}
+
+GLenum FramebufferState::Bind(GLenum target, GLuint framebuffer) {
+    if (MG_Constants::Framebuffer::VALID_TARGETS.find(target) == MG_Constants::Framebuffer::VALID_TARGETS.end()) 
+        return GL_INVALID_ENUM;
+    if (framebuffer != 0 && !ValidateHandle(framebuffer))
+        return GL_INVALID_OPERATION;
+    if (target == GL_FRAMEBUFFER) {
+        currentBindings_[GL_READ_FRAMEBUFFER] = framebuffer;
+        currentBindings_[GL_DRAW_FRAMEBUFFER] = framebuffer;
+        currentBindings_[GL_FRAMEBUFFER] = framebuffer;
+    } else {
+        currentBindings_[target] = framebuffer;
+    }
+    return GL_NO_ERROR;
+}
+
+GLenum FramebufferState::glAttachTexture2D(GLenum target, GLenum attachment,
+                                           GLenum textarget, GLuint texture, GLint level) {
+    if (MG_Constants::Framebuffer::VALID_ATTACHMENTS.find(attachment) == MG_Constants::Framebuffer::VALID_ATTACHMENTS.end() ||
+        MG_Constants::Texture::VALID_TARGETS.find(textarget) == MG_Constants::Texture::VALID_TARGETS.end())
+        return GL_INVALID_ENUM;
+    FramebufferObject* fbo = GetCurrentFBO(target);
+    if (!fbo) return GL_INVALID_OPERATION;
+    if (texture != 0 && !MG_State_T::textureState->IsTexture(texture))
+        return GL_INVALID_VALUE;
+    FramebufferAttachment att;
+    att.type = GL_TEXTURE_2D;
+    att.handle = texture;
+    att.mipLevel = level;
+    fbo->attachments[attachment] = att;
+    
+    if (texture != 0) {
+        GLint params = 0;
+        MG_State_T::textureState->QueryLevelPropertyIntVector(
+            textarget, level, GL_TEXTURE_WIDTH, &params);
+        fbo->width = params;
+        MG_State_T::textureState->QueryLevelPropertyIntVector(
+            textarget, level, GL_TEXTURE_HEIGHT, &params);
+        fbo->height = params;
+    }
+    UpdateCompleteness(*fbo);
+    return GL_NO_ERROR;
+}
+
+GLenum FramebufferState::glValidateCompleteness(GLenum target) {
+    FramebufferObject* fbo = GetCurrentFBO(target);
+    if (!fbo) return GL_INVALID_OPERATION;
+    return fbo->status;
+}
+
+void FramebufferState::UpdateCompleteness(FramebufferObject& fbo) {
+    if (fbo.attachments.empty()) {
+        fbo.status = GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT;
+        return;
+    }
+    bool hasColor = false;
+    bool hasDepth = false;
+    bool hasStencil = false;
+    GLsizei width = 0, height = 0;
+    for (const auto& [attach, att] : fbo.attachments) {
+        GLsizei attWidth = 0, attHeight = 0;
+        if (att.handle != 0) {
+            GLint params = 0;
+            MG_State_T::textureState->QueryLevelPropertyIntVector(
+                GL_TEXTURE_2D, att.mipLevel, GL_TEXTURE_WIDTH, &params);
+            attWidth = params;
+            MG_State_T::textureState->QueryLevelPropertyIntVector(
+                GL_TEXTURE_2D, att.mipLevel, GL_TEXTURE_HEIGHT, &params);
+            attHeight = params;
+        }
+        if (width == 0) {
+            width = attWidth;
+            height = attHeight;
+        } else if (attWidth != width || attHeight != height) {
+            fbo.status = GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS;
+            return;
+        }
+        
+        if (attach == GL_DEPTH_ATTACHMENT) hasDepth = true;
+        if (attach == GL_STENCIL_ATTACHMENT) hasStencil = true;
+        if (attach >= GL_COLOR_ATTACHMENT0 && 
+            attach <= GL_COLOR_ATTACHMENT31) hasColor = true;
+    }
+    
+    if (!ValidateAttachmentCombination(fbo)) {
+        fbo.status = GL_FRAMEBUFFER_UNSUPPORTED;
+        return;
+    }
+    fbo.status = GL_FRAMEBUFFER_COMPLETE;
+}
+
+bool FramebufferState::ValidateAttachmentCombination(const FramebufferObject& fbo) {
+    bool depthStencilConflict = false;
+    for (const auto& [attach, att] : fbo.attachments) {
+        if (attach == GL_DEPTH_STENCIL_ATTACHMENT) {
+            GLint internalFormat = 0;
+            MG_State_T::textureState->QueryLevelPropertyIntVector(
+                GL_TEXTURE_2D, att.mipLevel, GL_TEXTURE_INTERNAL_FORMAT, &internalFormat);
+            if (internalFormat != GL_DEPTH24_STENCIL8 && 
+                internalFormat != GL_DEPTH32F_STENCIL8) {
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+FramebufferObject* FramebufferState::GetCurrentFBO(GLenum target) {
+    auto it = currentBindings_.find(target);
+    if (it == currentBindings_.end()) return nullptr;
+    
+    GLuint id = it->second;
+    if (id == 0) return nullptr;
+    
+    auto fboIt = framebuffers_.find(id);
+    return (fboIt != framebuffers_.end()) ? &fboIt->second : nullptr;
+}
+
+bool FramebufferState::ValidateHandle(GLuint framebuffer) {
+    return framebuffers_.count(framebuffer) && 
+           framebuffers_[framebuffer].generated;
+}