Merge branch 'Feat/Backend-Direct-GLES' into dev

MobileGL/MG_Backend/DirectGLES/DirectGLES.cpp

@@ -8,8 +8,11 @@
 
 #include "DirectGLES.h"
 #include "GLES3/gl32.h"
+#include "MG_State/GLState/ErrorState/Error.h"
+#include "MG_State/GLState/RenderState/RenderState.h"
 #include "MG_State/GLState/SamplerState/SamplerObject.h"
 #include "MG_Util/Debug/Log.h"
+#include "MG_Util/Types.h"
 #include "Utils.h"
 #include "Managers.h"
 #include <MG_Util/Converters/GLToMG/TextureEnumConverter.h>
@@ -882,8 +885,8 @@ namespace MobileGL::MG_Backend::DirectGLES {
 
         auto textureTarget = MG_Util::ConvertGLEnumToTextureTarget(target);
         if (!TextureImpl::IsSupportedTextureTarget(textureTarget)) {
-            MOBILEGL_ASSERT(false, "    Texture target %s is not supported, skipping.",
+            MGLOG_E("    Texture target %s is not supported, skipping.",
-                            MG_Util::ConvertTextureTargetToString(textureTarget).c_str());
+                    MG_Util::ConvertTextureTargetToString(textureTarget).c_str());
             return false;
         }
 
@@ -909,26 +912,40 @@ namespace MobileGL::MG_Backend::DirectGLES {
     }
 
     static GLuint s_prevDrawFBO = 0;
-    void BindTempDrawFBO() {
+    static GLuint s_prevReadFBO = 0;
+    void BindTempFBO(Bool isRead) {
         MGLOG_D("%s: Binding temporary FBO for operations like CopyTexImage2D that require framebuffer binding, "
-                "previous draw FBO=%u",
+                "previous draw FBO=%u, read FBO=%u",
-                __func__, s_prevDrawFBO);
+                __func__, s_prevDrawFBO, s_prevReadFBO);
         static GLuint tempFBO = 0;
         if (!tempFBO) {
             MG_External::GLES::glGenFramebuffers(1, &tempFBO);
         }
-        MG_External::GLES::glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, (GLint*)&s_prevDrawFBO);
+        if (isRead) {
-        MG_External::GLES::glBindFramebuffer(GL_DRAW_FRAMEBUFFER, tempFBO);
+            MG_External::GLES::glGetIntegerv(GL_READ_FRAMEBUFFER_BINDING, (GLint*)&s_prevReadFBO);
+            MG_External::GLES::glBindFramebuffer(GL_READ_FRAMEBUFFER, tempFBO);
+        } else {
+            MG_External::GLES::glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, (GLint*)&s_prevDrawFBO);
+            MG_External::GLES::glBindFramebuffer(GL_DRAW_FRAMEBUFFER, tempFBO);
+        }
     }
-    void RestoreDrawFBOFromTemp() {
+    void RestoreFBOFromTemp(Bool isRead) {
-        MGLOG_D("%s: Restoring previous draw FBO=%u", __func__, s_prevDrawFBO);
+        if (isRead) {
-        MG_External::GLES::glBindFramebuffer(GL_DRAW_FRAMEBUFFER, s_prevDrawFBO);
+            MGLOG_D("%s: Restoring previous read FBO=%u", __func__, s_prevReadFBO);
+            MG_External::GLES::glBindFramebuffer(GL_READ_FRAMEBUFFER, s_prevReadFBO);
+        } else {
+            MGLOG_D("%s: Restoring previous draw FBO=%u", __func__, s_prevDrawFBO);
+            MG_External::GLES::glBindFramebuffer(GL_DRAW_FRAMEBUFFER, s_prevDrawFBO);
+        }
     }
 
     class TempFBOBinder {
     public:
-        TempFBOBinder() { BindTempDrawFBO(); }
+        TempFBOBinder(Bool isRead) : m_isRead(isRead) { BindTempFBO(isRead); }
-        ~TempFBOBinder() { RestoreDrawFBOFromTemp(); }
+        ~TempFBOBinder() { RestoreFBOFromTemp(m_isRead); }
+
+    private:
+        const Bool m_isRead = false;
     };
 
     void CopyTexImage2D(GLenum target, GLint level, GLenum internalformat, GLint x, GLint y, GLsizei width,
@@ -1001,7 +1018,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
             });
 
             GLenum attachment = isStencilFormat ? GL_DEPTH_STENCIL_ATTACHMENT : GL_DEPTH_ATTACHMENT;
-            TempFBOBinder tempFBOBinder;
+            TempFBOBinder tempFBOBinder(false);
             MG_External::GLES::glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, attachment, target, currentTex, level);
 
             if (MG_External::GLES::glCheckFramebufferStatus(GL_DRAW_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
@@ -1080,7 +1097,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
                 MGLOG_D("ES error (%s:%d): %s", file, line, MG_Util::ConvertGLEnumToString(err).c_str());
             });
             GLenum attachment = isStencilFormat ? GL_DEPTH_STENCIL_ATTACHMENT : GL_DEPTH_ATTACHMENT;
-            TempFBOBinder tempFBOBinder;
+            TempFBOBinder tempFBOBinder(false);
             MG_External::GLES::glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, attachment, target, currentTex, level);
             errorLopper.Loop([file = __FILE__, line = __LINE__](auto err) {
                 MGLOG_D("ES error (%s:%d): %s", file, line, MG_Util::ConvertGLEnumToString(err).c_str());
@@ -1136,6 +1153,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
 
         MG_External::GLES::glClearBufferfv(buffer, drawbuffer, value);
     }
+
     void ClearBufferiv(GLenum buffer, GLint drawbuffer, const GLint* value) {
         TextureImpl::SyncNeccessaryTextures();
         FramebufferImpl::SyncCurrentFBO();
@@ -1154,4 +1172,289 @@ namespace MobileGL::MG_Backend::DirectGLES {
         MG_External::GLES::glClearBufferuiv(buffer, drawbuffer, value);
     }
 
-} // namespace MobileGL::MG_Backend::DirectGLES
+    class TempPixelStoreParameterSync {
+    public:
+        TempPixelStoreParameterSync(Bool isUnpack) : m_isUnpack(isUnpack) {
+            const auto& currentParams = MG_State::pGLContext->GetPixelStoreParameters(isUnpack);
+            m_prevParams = QueryCurrentGLPixelStoreParams(isUnpack);
+            Sync(isUnpack, currentParams);
+        }
+
+        ~TempPixelStoreParameterSync() { Sync(m_isUnpack, m_prevParams); }
+
+    private:
+        const Bool m_isUnpack;
+
+        PixelStoreParameters m_prevParams;
+
+        PixelStoreParameters QueryCurrentGLPixelStoreParams(Bool isUnpack) {
+            PixelStoreParameters p;
+            if (!isUnpack) {
+                MG_External::GLES::glGetIntegerv(GL_PACK_ALIGNMENT, (GLint*)&p.Alignment);
+                MG_External::GLES::glGetIntegerv(GL_PACK_ROW_LENGTH, (GLint*)&p.RowLength);
+                MG_External::GLES::glGetIntegerv(GL_PACK_SKIP_ROWS, (GLint*)&p.SkipRows);
+                MG_External::GLES::glGetIntegerv(GL_PACK_SKIP_PIXELS, (GLint*)&p.SkipPixels);
+                // MG_External::GLES::glGetIntegerv(GL_PACK_IMAGE_HEIGHT, (GLint*)&p.ImageHeight);
+                // MG_External::GLES::glGetIntegerv(GL_PACK_SKIP_IMAGES, (GLint*)&p.SkipImages);
+                // GLint tmp;
+                // MG_External::GLES::glGetIntegerv(GL_PACK_SWAP_BYTES, &tmp);
+                // p.SwapBytes = tmp ? true : false;
+                // MG_External::GLES::glGetIntegerv(GL_PACK_LSB_FIRST, &tmp);
+                // p.LSBFirst = tmp ? true : false;
+            } else {
+                MG_External::GLES::glGetIntegerv(GL_UNPACK_ALIGNMENT, (GLint*)&p.Alignment);
+                MG_External::GLES::glGetIntegerv(GL_UNPACK_ROW_LENGTH, (GLint*)&p.RowLength);
+                MG_External::GLES::glGetIntegerv(GL_UNPACK_SKIP_ROWS, (GLint*)&p.SkipRows);
+                MG_External::GLES::glGetIntegerv(GL_UNPACK_SKIP_PIXELS, (GLint*)&p.SkipPixels);
+                MG_External::GLES::glGetIntegerv(GL_UNPACK_IMAGE_HEIGHT, (GLint*)&p.ImageHeight);
+                MG_External::GLES::glGetIntegerv(GL_UNPACK_SKIP_IMAGES, (GLint*)&p.SkipImages);
+                // GLint tmp;
+                // MG_External::GLES::glGetIntegerv(GL_UNPACK_SWAP_BYTES, &tmp);
+                // p.SwapBytes = tmp ? true : false;
+                // MG_External::GLES::glGetIntegerv(GL_UNPACK_LSB_FIRST, &tmp);
+                // p.LSBFirst = tmp ? true : false;
+            }
+            return p;
+        }
+
+        void Sync(Bool isUnpack, const PixelStoreParameters& params) {
+            if (!isUnpack) {
+                MG_External::GLES::glPixelStorei(GL_PACK_ALIGNMENT, params.Alignment);
+                MG_External::GLES::glPixelStorei(GL_PACK_ROW_LENGTH, params.RowLength);
+                MG_External::GLES::glPixelStorei(GL_PACK_SKIP_ROWS, params.SkipRows);
+                MG_External::GLES::glPixelStorei(GL_PACK_SKIP_PIXELS, params.SkipPixels);
+                // MG_External::GLES::glPixelStorei(GL_PACK_IMAGE_HEIGHT, params.ImageHeight);
+                // MG_External::GLES::glPixelStorei(GL_PACK_SKIP_IMAGES, params.SkipImages);
+                // MG_External::GLES::glPixelStorei(GL_PACK_SWAP_BYTES, params.SwapBytes ? GL_TRUE : GL_FALSE);
+                // MG_External::GLES::glPixelStorei(GL_PACK_LSB_FIRST, params.LSBFirst ? GL_TRUE : GL_FALSE);
+            } else {
+                MG_External::GLES::glPixelStorei(GL_UNPACK_ALIGNMENT, params.Alignment);
+                MG_External::GLES::glPixelStorei(GL_UNPACK_ROW_LENGTH, params.RowLength);
+                MG_External::GLES::glPixelStorei(GL_UNPACK_SKIP_ROWS, params.SkipRows);
+                MG_External::GLES::glPixelStorei(GL_UNPACK_SKIP_PIXELS, params.SkipPixels);
+                MG_External::GLES::glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, params.ImageHeight);
+                MG_External::GLES::glPixelStorei(GL_UNPACK_SKIP_IMAGES, params.SkipImages);
+                // MG_External::GLES::glPixelStorei(GL_UNPACK_SWAP_BYTES, params.SwapBytes ? GL_TRUE : GL_FALSE);
+                // MG_External::GLES::glPixelStorei(GL_UNPACK_LSB_FIRST, params.LSBFirst ? GL_TRUE : GL_FALSE);
+            }
+        }
+    };
+
+    void ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels) {
+        MGLOG_D("ReadPixels: x=%d y=%d w=%d h=%d format=%s type=%s pixels=%p", x, y, width, height,
+                MG_Util::ConvertGLEnumToString(format).c_str(), MG_Util::ConvertGLEnumToString(type).c_str(), pixels);
+
+        MOBILEGL_ASSERT(format == GL_RGBA || format == GL_RGBA_INTEGER,
+                        "Only GL_RGBA and GL_RGBA_INTEGER are supported currently, while requested %s.",
+                        MG_Util::ConvertGLEnumToString(format).c_str());
+        MOBILEGL_ASSERT(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT || type == GL_UNSIGNED_INT_2_10_10_10_REV ||
+                            type == GL_INT || type == GL_FLOAT,
+                        "Only GL_UNSIGNED_BYTE, GL_UNSIGNED_INT, GL_UNSIGNED_INT_2_10_10_10_REV, "
+                        "GL_INT and GL_FLOAT are supported currently, while requested %s.",
+                        MG_Util::ConvertGLEnumToString(type).c_str());
+
+        MGLOG_D("ReadPixels: SyncNeccessaryTextures()");
+        TextureImpl::SyncNeccessaryTextures();
+
+        MGLOG_D("ReadPixels: SyncCurrentFBO()");
+        FramebufferImpl::SyncCurrentFBO();
+
+        MGLOG_D("ReadPixels: BindCurrentFBO(Read)");
+        BindCurrentFBO(FramebufferTarget::Read);
+
+        MGLOG_D("ReadPixels: Applying TempPixelStoreParameterSync (PACK)");
+        TempPixelStoreParameterSync tempPackParamsSync(false);
+
+        GLenum fbStatus = MG_External::GLES::glCheckFramebufferStatus(GL_READ_FRAMEBUFFER);
+        MGLOG_D("ReadPixels: GL_READ_FRAMEBUFFER status = %s", MG_Util::ConvertGLEnumToString(fbStatus).c_str());
+
+        if (fbStatus != GL_FRAMEBUFFER_COMPLETE) {
+            MGLOG_E("ReadPixels: bound READ FBO is not complete");
+            return;
+        }
+
+        // Handle PBO
+        auto pixelPackBufferObject =
+            MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::PixelPack).GetBoundObject();
+        Bool usePBO;
+        GLuint prevPixelPackBuffer = 0;
+        if (pixelPackBufferObject) {
+            BufferImpl::CreateAndSyncBufferObject(pixelPackBufferObject);
+            MGLOG_D("ReadPixels: Using PBO %u", pixelPackBufferObject->GetExternalIndex());
+            usePBO = true;
+            const auto& backendBufferIt = BufferImpl::g_backendBufferObjects.find(pixelPackBufferObject);
+
+            if (backendBufferIt == BufferImpl::g_backendBufferObjects.end()) {
+                MGLOG_E("ReadPixels: No backend buffer found for PBO %u.",
+                        pixelPackBufferObject ? pixelPackBufferObject->GetExternalIndex() : 0);
+                return;
+            }
+            const auto& backendBufferObject = backendBufferIt->second;
+            backendBufferObject->Bind(GL_PIXEL_PACK_BUFFER);
+            MG_External::GLES::glGetIntegerv(GL_PIXEL_PACK_BUFFER_BINDING, (GLint*)&prevPixelPackBuffer);
+        } else {
+            usePBO = false;
+            MGLOG_D("ReadPixels: Not using PBO");
+        }
+
+        MGLOG_D("ReadPixels: glReadPixels()");
+        MG_External::GLES::glReadPixels(x, y, width, height, format, type, pixels);
+        if (usePBO) {
+            // pull back to client memory if PBO is used
+            MGLOG_D("ReadPixels: PBO used, mapping buffer to client memory");
+            GLvoid* pboMappedPtr = MG_External::GLES::glMapBufferRange(
+                GL_PIXEL_PACK_BUFFER, 0, pixelPackBufferObject->GetSize(), GL_MAP_READ_BIT);
+            if (pboMappedPtr) {
+                MGLOG_D("ReadPixels: Copying data from PBO to client memory");
+                SizeT size = pixelPackBufferObject->GetSize();
+                pixelPackBufferObject->UploadSubData({pboMappedPtr, size}, 0);
+                pixelPackBufferObject->ClearDirty();
+                MGLOG_D("ReadPixels: Unmapping PBO");
+                MG_External::GLES::glUnmapBuffer(GL_PIXEL_PACK_BUFFER);
+            } else {
+                MGLOG_E("ReadPixels: glMapBufferRange returned nullptr");
+                MGLOG_E("ReadPixels: glMapBufferRange returned nullptr");
+            }
+            MGLOG_D("ReadPixels: Restoring previous pixel pack buffer binding %u", prevPixelPackBuffer);
+            MG_External::GLES::glBindBuffer(GL_PIXEL_PACK_BUFFER, prevPixelPackBuffer);
+        }
+        MGLOG_D("ReadPixels: finished");
+    }
+
+    void GetTexImage(GLenum target, GLint level, GLenum format, GLenum type, void* pixels) {
+        MGLOG_D("GetTexImage: target=%s level=%d format=%s type=%s pixels=%p",
+                MG_Util::ConvertGLEnumToString(target).c_str(), level, MG_Util::ConvertGLEnumToString(format).c_str(),
+                MG_Util::ConvertGLEnumToString(type).c_str(), pixels);
+
+        MOBILEGL_ASSERT(format == GL_RGBA || format == GL_RGBA_INTEGER,
+                        "Only GL_RGBA and GL_RGBA_INTEGER are supported currently, while requested %s.",
+                        MG_Util::ConvertGLEnumToString(format).c_str());
+        MOBILEGL_ASSERT(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT || type == GL_UNSIGNED_INT_2_10_10_10_REV ||
+                            type == GL_INT || type == GL_FLOAT,
+                        "Only GL_UNSIGNED_BYTE, GL_UNSIGNED_INT, GL_UNSIGNED_INT_2_10_10_10_REV, "
+                        "GL_INT and GL_FLOAT are supported currently, while requested %s.",
+                        MG_Util::ConvertGLEnumToString(type).c_str());
+
+        MGLOG_D("GetTexImage: SyncNeccessaryTextures()");
+        TextureImpl::SyncNeccessaryTextures();
+
+        MGLOG_D("GetTexImage: SyncCurrentFBO()");
+        FramebufferImpl::SyncCurrentFBO();
+
+        Uint activeTextureUnit = MG_State::pGLContext->GetActiveTextureUnit();
+        MGLOG_D("GetTexImage: active texture unit = %u", activeTextureUnit);
+
+        const auto& textureObject = MG_State::pGLContext->GetTextureUnitObject(activeTextureUnit)
+                                        .GetBindingSlot(MG_Util::ConvertGLEnumToTextureTarget(target))
+                                        .GetBoundObject();
+
+        MGLOG_D("GetTexImage: bound texture object = %p (name=%u)", textureObject.get(),
+                textureObject ? textureObject->GetExternalIndex() : 0);
+
+        const auto& backendTextureIt = TextureImpl::g_backendTextureObjects.find(textureObject);
+
+        if (backendTextureIt == TextureImpl::g_backendTextureObjects.end()) {
+            MGLOG_E("GetTexImage: No backend texture found for texture %u.",
+                    textureObject ? textureObject->GetExternalIndex() : 0);
+            return;
+        }
+
+        GLuint backendTexId = backendTextureIt->second->GetBackendTextureId();
+        MGLOG_D("GetTexImage: backend texture id = %u", backendTexId);
+
+        MGLOG_D("GetTexImage: Binding temporary FBO");
+        TempFBOBinder tempFBOBinder(true);
+
+        MGLOG_D("GetTexImage: glFramebufferTexture2D(level=%d)", level);
+        MG_External::GLES::glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, target, backendTexId,
+                                                  level);
+        MGLOG_D("GetTexImage: glReadBuffer(GL_COLOR_ATTACHMENT0)");
+        MG_External::GLES::glReadBuffer(GL_COLOR_ATTACHMENT0);
+
+        GLenum fbStatus = MG_External::GLES::glCheckFramebufferStatus(GL_READ_FRAMEBUFFER);
+        MGLOG_D("GetTexImage: GL_READ_FRAMEBUFFER status = %s", MG_Util::ConvertGLEnumToString(fbStatus).c_str());
+
+        if (fbStatus != GL_FRAMEBUFFER_COMPLETE) {
+            MGLOG_E("GetTexImage: READ FBO incomplete");
+            MGLOG_E("GetTexImage: bound READ FBO is not complete");
+            return;
+        }
+
+        MGLOG_D("GetTexImage: Applying TempPixelStoreParameterSync (PACK)");
+        TempPixelStoreParameterSync tempPackParamsSync(false);
+
+        const auto& storageType = textureObject->GetStorageType();
+        MGLOG_D("GetTexImage: texture storage type = %d", (int)storageType);
+
+        if (storageType == TextureStorageType::Buffer) {
+            MGLOG_E("GetTexImage: Texture storage type Buffer is not supported.");
+            MGLOG_E("GetTexImage: Texture storage type Buffer is not supported.");
+            return;
+        }
+
+        auto* textureMipmapObject = static_cast<MG_State::GLState::TextureObjectMipmap*>(textureObject.get());
+
+        auto levelRange = textureMipmapObject->GetLevelRange();
+        MGLOG_D("GetTexImage: mipmap level range = [%d, %d)", levelRange.x(), levelRange.y());
+
+        if (level < levelRange.x() || level >= levelRange.y()) {
+            MGLOG_E("GetTexImage: Requested level %d out of range", level);
+            MOBILEGL_ASSERT(false,
+                            "GetTexImage: Requested level %d is out of range "
+                            "(base level %d, max level %d).",
+                            level, levelRange.x(), levelRange.y());
+            return;
+        }
+
+        auto size = textureMipmapObject->GetMipmapTexelSize(MG_Util::ConvertGLEnumToTextureUploadTarget(target), level);
+
+        MGLOG_D("GetTexImage: mip level %d size = %dx%d", level, size.x(), size.y());
+
+        // Handle PBO
+        auto pixelPackBufferObject =
+            MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::PixelPack).GetBoundObject();
+        Bool usePBO;
+        GLuint prevPixelPackBuffer = 0;
+        if (pixelPackBufferObject) {
+            BufferImpl::CreateAndSyncBufferObject(pixelPackBufferObject);
+            MGLOG_D("GetTexImage: Using PBO %u", pixelPackBufferObject->GetExternalIndex());
+            usePBO = true;
+            const auto& backendBufferIt = BufferImpl::g_backendBufferObjects.find(pixelPackBufferObject);
+            if (backendBufferIt == BufferImpl::g_backendBufferObjects.end()) {
+                MGLOG_E("GetTexImage: No backend buffer found for PBO %u.",
+                        pixelPackBufferObject ? pixelPackBufferObject->GetExternalIndex() : 0);
+                return;
+            }
+            const auto& backendBufferObject = backendBufferIt->second;
+            backendBufferObject->Bind(GL_PIXEL_PACK_BUFFER);
+            MG_External::GLES::glGetIntegerv(GL_PIXEL_PACK_BUFFER_BINDING, (GLint*)&prevPixelPackBuffer);
+        } else {
+            usePBO = false;
+            MGLOG_D("GetTexImage: Not using PBO");
+        }
+        MGLOG_D("GetTexImage: glReadPixels()");
+        MG_External::GLES::glReadPixels(0, 0, size.x(), size.y(), format, type, pixels);
+        if (usePBO) {
+            // pull back to client memory if PBO is used
+            MGLOG_D("ReadPixels: PBO used, mapping buffer to client memory");
+            GLvoid* pboMappedPtr = MG_External::GLES::glMapBufferRange(
+                GL_PIXEL_PACK_BUFFER, 0, pixelPackBufferObject->GetSize(), GL_MAP_READ_BIT);
+            if (pboMappedPtr) {
+                MGLOG_D("ReadPixels: Copying data from PBO to client memory");
+                SizeT size = pixelPackBufferObject->GetSize();
+                pixelPackBufferObject->UploadSubData({pboMappedPtr, size}, 0);
+                pixelPackBufferObject->ClearDirty();
+                MGLOG_D("ReadPixels: Unmapping PBO");
+                MG_External::GLES::glUnmapBuffer(GL_PIXEL_PACK_BUFFER);
+            } else {
+                MGLOG_E("ReadPixels: glMapBufferRange returned nullptr");
+                MGLOG_E("ReadPixels: glMapBufferRange returned nullptr");
+            }
+            MGLOG_D("ReadPixels: Restoring previous pixel pack buffer binding %u", prevPixelPackBuffer);
+
+            MG_External::GLES::glBindBuffer(GL_PIXEL_PACK_BUFFER, prevPixelPackBuffer);
+        }
+        MGLOG_D("GetTexImage: finished");
+    }
+
+} // namespace MobileGL::MG_Backend::DirectGLES

MobileGL/MG_Backend/DirectGLES/DirectGLES.h

@@ -53,4 +53,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
                            GLsizei height);
     void GenerateMipmap(GLenum target);
     const GLubyte* GetString(GLenum name);
+    void ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels);
+    void GetTexImage(GLenum target, GLint level, GLenum format, GLenum type, GLvoid* pixels);
+
 } // namespace MobileGL::MG_Backend::DirectGLES

MobileGL/MG_Impl/GLImpl/Exporting/Definitions.cpp

@@ -151,7 +151,7 @@ DECLARE_GL_FUNCTION_HEAD(void, LineWidth, GLfloat width) DECLARE_GL_FUNCTION_END
 DECLARE_GL_FUNCTION_HEAD(void, LinkProgram, GLuint program) DECLARE_GL_FUNCTION_END_NO_RETURN(void, LinkProgram, program)
 DECLARE_GL_FUNCTION_HEAD(void, PixelStorei, GLenum pname, GLint param) DECLARE_GL_FUNCTION_END_NO_RETURN(void, PixelStorei, pname, param)
 DECLARE_GL_FUNCTION_HEAD(void, PolygonOffset, GLfloat factor, GLfloat units) DECLARE_GL_FUNCTION_END_NO_RETURN(void, PolygonOffset, factor, units)
-DECLARE_GL_FUNCTION_STUB_HEAD(void, ReadPixels, GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, ReadPixels, x, y, width, height, format, type, pixels)
+DECLARE_GL_FUNCTION_HEAD(void, ReadPixels, GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels) DECLARE_GL_FUNCTION_END_NO_RETURN(void, ReadPixels, x, y, width, height, format, type, pixels)
 DECLARE_GL_FUNCTION_STUB_HEAD(void, ReleaseShaderCompiler) DECLARE_GL_FUNCTION_STUB_END_NO_RETURN(void, ReleaseShaderCompiler)
 DECLARE_GL_FUNCTION_HEAD(void, RenderbufferStorage, GLenum target, GLenum internalformat, GLsizei width, GLsizei height) DECLARE_GL_FUNCTION_END_NO_RETURN(void, RenderbufferStorage, target, internalformat, width, height)
 DECLARE_GL_FUNCTION_HEAD(void, SampleCoverage, GLfloat value, GLboolean invert) DECLARE_GL_FUNCTION_END_NO_RETURN(void, SampleCoverage, value, invert)

MobileGL/MG_Impl/GLImpl/Framebuffer/GL_Framebuffer.cpp

@@ -9,6 +9,7 @@
 #include "GL_Framebuffer.h"
 #include "Validators.h"
 #include "Config.h"
+#include <MG_Util/Metrics/TextureMetrics.h>
 #include <MG_Impl/GLImpl/Texture/Validators.h>
 #include <MG_State/GLState/ErrorState/Error.h>
 #include <MG_Util/Converters/GLToStr/GLEnumConverter.h>
@@ -310,10 +311,10 @@ namespace MobileGL {
             // ------------------- Check validity begin ------------------------
             if (attType == FramebufferAttachmentType::Unknown) {
                 MG_State::pGLContext->RecordError(
-                        ErrorCode::InvalidEnum,
+                    ErrorCode::InvalidEnum,
-                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                    MakeShared<GenericErrorInfo>(
-                                                     std::format("`mode` = {} is not an accepted value.",
+                        "MG_Impl/GLImpl", __func__,
-                                                                 MG_Util::ConvertGLEnumToString(mode))));
+                        std::format("`mode` = {} is not an accepted value.", MG_Util::ConvertGLEnumToString(mode))));
                 return;
             }
 
@@ -507,7 +508,142 @@ namespace MobileGL {
 #endif
         }
 
+        void ReadPixels_State(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type,
+                              void* pixels) {
+            TextureInputFormat textureInputFormat = MG_Util::ConvertGLEnumToTextureInputFormat(format);
+            TexturePixelDataType texturePixelDataType = MG_Util::ConvertGLEnumToTexturePixelDataType(type);
+
+            // Check width/height
+            if (width < 0 || height < 0) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidValue, MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State",
+                                                                          "Width and height must be non-negative"));
+                return;
+            }
+
+            // Validate format
+            if (!TextureImpl::ValidateTextureInputFormat(textureInputFormat)) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidEnum,
+                    MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State", "Invalid format"));
+                return;
+            }
+
+            // Validate type
+            if (!TextureImpl::ValidateTexturePixelDataType(texturePixelDataType)) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidEnum,
+                    MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State", "Invalid pixel data type"));
+                return;
+            }
+
+            // Get bound framebuffer
+            auto& bindingSlot = MG_State::pGLContext->GetFramebufferBindingSlot(FramebufferTarget::Read);
+            auto framebufferObject = bindingSlot.GetBoundObject();
+
+            if (!framebufferObject) {
+                MG_State::pGLContext->RecordError(ErrorCode::InvalidOperation,
+                                                  MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State",
+                                                                               "No framebuffer bound to read target"));
+                return;
+            }
+
+            // Check framebuffer completeness
+            if (!framebufferObject->CheckCompleteness()) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidFramebufferOperation,
+                    MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State", "Framebuffer is incomplete"));
+                return;
+            }
+
+            // Check for required buffers
+            if (textureInputFormat == TextureInputFormat::StencilIndex) {
+                if (!framebufferObject->GetAttachment(FramebufferAttachmentType::Stencil).IsValid()) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidOperation,
+                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State",
+                                                     "No stencil buffer for stencil index format"));
+                    return;
+                }
+            } else if (textureInputFormat == TextureInputFormat::DepthComponent) {
+                if (!framebufferObject->GetAttachment(FramebufferAttachmentType::Depth).IsValid()) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidOperation,
+                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State",
+                                                     "No depth buffer for depth component format"));
+                    return;
+                }
+            } else if (textureInputFormat == TextureInputFormat::DepthStencil) {
+                if (!framebufferObject->GetAttachment(FramebufferAttachmentType::Depth).IsValid() ||
+                    !framebufferObject->GetAttachment(FramebufferAttachmentType::Stencil).IsValid()) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidOperation,
+                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State",
+                                                     "No depth/stencil buffer for depth-stencil format"));
+                    return;
+                }
+
+                // Validate type for depth/stencil
+                if (texturePixelDataType != TexturePixelDataType::UnsignedInt248 &&
+                    texturePixelDataType != TexturePixelDataType::Float32UnsignedInt248Rev) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidEnum, MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State",
+                                                                             "Invalid type for depth-stencil format"));
+                    return;
+                }
+            }
+
+            // Check PBO state
+            const auto& pixelPackBufferObject =
+                MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::PixelPack).GetBoundObject();
+
+            if (pixelPackBufferObject) {
+                // Check if PBO is mapped
+                if (pixelPackBufferObject->IsMapped()) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidOperation,
+                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State",
+                                                     "Pixel pack buffer is currently mapped"));
+                    return;
+                }
+
+                // Check alignment
+                const SizeT typeSize = MG_Util::GetTexturePixelDataTypeSize(texturePixelDataType);
+                if (reinterpret_cast<uintptr_t>(pixels) % typeSize != 0) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidOperation,
+                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State",
+                                                     "Pixel data not aligned for pixel pack buffer"));
+                    return;
+                }
+            }
+
+            // Check multisampling
+            if (framebufferObject->GetAttachment(FramebufferAttachmentType::Color0).IsRenderbuffer()) {
+                auto rbo = framebufferObject->GetAttachment(FramebufferAttachmentType::Color0).GetRenderbuffer();
+                if (rbo && rbo->GetSamples() > 1) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidOperation,
+                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "ReadPixels_State",
+                                                     "ReadPixels not supported for multisampled framebuffers"));
+                    return;
+                }
+            }
+        }
+
+        void ReadPixels_Backend(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type,
+                                void* pixels) {
+#if MOBILEGL_BACKEND == MOBILEGL_BACKEND_TYPE_DIRECT_GLES
+            MG_Backend::DirectGLES::ReadPixels(x, y, width, height, format, type, pixels);
+#endif
+        }
+
         /* @INSERTION_POINT:FUNCTION_IMPLEMENTATION@ */
+        void ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels) {
+            ReadPixels_State(x, y, width, height, format, type, pixels);
+            ReadPixels_Backend(x, y, width, height, format, type, pixels);
+        }
+
         void ClearBufferfi(GLenum buffer, GLint drawbuffer, GLfloat depth, GLint stencil) {
             ClearBufferfi_Backend(buffer, drawbuffer, depth, stencil);
         }

MobileGL/MG_Impl/GLImpl/Framebuffer/GL_Framebuffer.h

@@ -14,6 +14,7 @@
 namespace MobileGL {
     namespace MG_Impl::GLImpl {
         /* @INSERTION_POINT:FUNCTION_DECLARATION@ */
+        void ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels);
         void ClearBufferfi(GLenum buffer, GLint drawbuffer, GLfloat depth, GLint stencil);
         void ClearBufferfv(GLenum buffer, GLint drawbuffer, const GLfloat* value);
         void ClearBufferuiv(GLenum buffer, GLint drawbuffer, const GLuint* value);

MobileGL/MG_Impl/GLImpl/Texture/GL_Texture.cpp

@@ -1164,10 +1164,6 @@ namespace MobileGL {
             }
         }
 
-        void GetTexImage_State(GLenum target, GLint level, GLenum format, GLenum type, GLvoid* pixels) {
-            // TODO: implement
-        }
-
         void GetCompressedTexImage_State(GLenum target, GLint level, void* img) {
             // TODO: implement
         }
@@ -1378,7 +1374,136 @@ namespace MobileGL {
             MG_State::pGLContext->SetActiveTextureUnit(texture - GL_TEXTURE0);
         }
 
+        void GetTexImage_Backend(GLenum target, GLint level, GLenum format, GLenum type, GLvoid* pixels) {
+#if MOBILEGL_BACKEND == MOBILEGL_BACKEND_TYPE_DIRECT_GLES
+            MG_Backend::DirectGLES::GetTexImage(target, level, format, type, pixels);
+#endif
+        }
+
+        // Add to GL_Texture.cpp
+        void GetTexImage_State(GLenum target, GLint level, GLenum format, GLenum type, GLvoid* pixels) {
+            // ======================= Converting ================================
+            TextureUploadTarget textureUploadTarget = MG_Util::ConvertGLEnumToTextureUploadTarget(target);
+            TextureTarget textureTarget = MG_Util::ConvertGLEnumToTextureTarget(target);
+            TextureInputFormat textureInputFormat = MG_Util::ConvertGLEnumToTextureInputFormat(format);
+            TexturePixelDataType texturePixelDataType = MG_Util::ConvertGLEnumToTexturePixelDataType(type);
+
+            // ===================== Error Checking ==============================
+            // Validate target
+            if (!TextureImpl::ValidateTextureUploadTarget(textureUploadTarget)) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidEnum,
+                    MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "GetTexImage_State", "Invalid texture target"));
+                return;
+            }
+
+            // Validate level
+            if (level < 0) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidValue,
+                    MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "GetTexImage_State", "Level must be non-negative"));
+                return;
+            }
+
+            // Validate format
+            if (!TextureImpl::ValidateTextureInputFormat(textureInputFormat)) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidEnum,
+                    MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "GetTexImage_State", "Invalid format"));
+                return;
+            }
+
+            // Validate type
+            if (!TextureImpl::ValidateTexturePixelDataType(texturePixelDataType)) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidEnum,
+                    MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "GetTexImage_State", "Invalid pixel data type"));
+                return;
+            }
+
+            // Get texture object
+            SharedPtr<MG_State::GLState::ITextureObject> textureObject = nullptr;
+            if (TextureImpl::IsProxyTextureTarget(textureUploadTarget)) {
+                textureObject = TextureImpl::pProxyTextureManager->GetProxyTextureObject(textureUploadTarget);
+            } else {
+                auto activeUnit =
+                    MG_State::pGLContext->GetTextureUnitObject(MG_State::pGLContext->GetActiveTextureUnit());
+                auto& bindingSlot = activeUnit.GetBindingSlot(textureTarget);
+                textureObject = bindingSlot.GetBoundObject();
+            }
+
+            if (!TextureImpl::ValidateTextureObject(textureObject)) {
+                MG_State::pGLContext->RecordError(ErrorCode::InvalidOperation,
+                                                  MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "GetTexImage_State",
+                                                                               "No valid texture bound to target"));
+                return;
+            }
+
+            // Check texture completeness
+            if (!textureObject->IsComplete()) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidOperation,
+                    MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "GetTexImage_State", "Texture is incomplete"));
+                return;
+            }
+
+            // Check PBO state
+            const auto& pixelPackBufferObject =
+                MG_State::pGLContext->GetBufferBindingSlot(BufferTarget::PixelPack).GetBoundObject();
+
+            if (pixelPackBufferObject) {
+                // Check if PBO is mapped
+                if (pixelPackBufferObject->IsMapped()) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidOperation,
+                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "GetTexImage_State",
+                                                     "Pixel pack buffer is currently mapped"));
+                    return;
+                }
+
+                // Check alignment
+                const SizeT typeSize = MG_Util::GetTexturePixelDataTypeSize(texturePixelDataType);
+                if (reinterpret_cast<uintptr_t>(pixels) % typeSize != 0) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidOperation,
+                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "GetTexImage_State",
+                                                     "Pixel data not aligned for pixel pack buffer"));
+                    return;
+                }
+            }
+
+            // Special case for depth/stencil
+            if (textureInputFormat == TextureInputFormat::StencilIndex) {
+                if (textureObject->GetFormat() != TextureInternalFormat::DepthStencil &&
+                    textureObject->GetFormat() != TextureInternalFormat::Depth24Stencil8 &&
+                    textureObject->GetFormat() != TextureInternalFormat::Depth32FStencil8) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidOperation,
+                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "GetTexImage_State",
+                                                     "No stencil buffer for stencil index format"));
+                    return;
+                }
+            }
+
+            // Check for multisampling
+            if (textureObject->GetStorageType() == TextureStorageType::Mipmap) {
+                auto mipmapObject = static_cast<MG_State::GLState::TextureObjectMipmap*>(textureObject.get());
+                if (mipmapObject->GetMipmapLevelCount() > 1) {
+                    MG_State::pGLContext->RecordError(
+                        ErrorCode::InvalidOperation,
+                        MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", "GetTexImage_State",
+                                                     "Multisampled textures not supported for GetTexImage"));
+                    return;
+                }
+            }
+        }
+
         /* @INSERTION_POINT:FUNCTION_IMPLEMENTATION@ */
+        void GetTexImage(GLenum target, GLint level, GLenum format, GLenum type, GLvoid* pixels) {
+            GetTexImage_State(target, level, format, type, pixels);
+            GetTexImage_Backend(target, level, format, type, pixels);
+        }
+
         void TexSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width,
                            GLsizei height, GLsizei depth, GLenum format, GLenum type, const void* pixels) {
             TexSubImage3D_State(target, level, xoffset, yoffset, zoffset, width, height, depth, format, type, pixels);
@@ -1475,10 +1600,6 @@ namespace MobileGL {
             GetTexLevelParameterfv_State(target, level, pname, params);
         }
 
-        void GetTexImage(GLenum target, GLint level, GLenum format, GLenum type, GLvoid* pixels) {
-            GetTexImage_State(target, level, format, type, pixels);
-        }
-
         void GetCompressedTexImage(GLenum target, GLint level, void* img) {
             GetCompressedTexImage_State(target, level, img);
         }

MobileGL/MG_Impl/GLImpl/Texture/GL_Texture.h

@@ -12,6 +12,7 @@
 namespace MobileGL {
     namespace MG_Impl::GLImpl {
         /* @INSERTION_POINT:FUNCTION_DECLARATION@ */
+        void GetTexImage(GLenum target, GLint level, GLenum format, GLenum type, GLvoid* pixels);
         void TexSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width,
                            GLsizei height, GLsizei depth, GLenum format, GLenum type, const void* pixels);
         void TexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height,
@@ -43,7 +44,6 @@ namespace MobileGL {
         void GetTexParameterfv(GLenum target, GLenum pname, GLfloat* params);
         void GetTexLevelParameteriv(GLenum target, GLint level, GLenum pname, GLint* params);
         void GetTexLevelParameterfv(GLenum target, GLint level, GLenum pname, GLfloat* params);
-        void GetTexImage(GLenum target, GLint level, GLenum format, GLenum type, GLvoid* pixels);
         void GetCompressedTexImage(GLenum target, GLint level, void* img);
         void GenTextures(GLsizei n, GLuint* textures);
         void DeleteTextures(GLsizei n, const GLuint* textures);

MobileGL/MG_Util/Metrics/TextureMetrics.cpp

@@ -239,6 +239,12 @@ namespace MobileGL {
             }
         }
 
+        SizeT GetTexturePixelDataTypeSize(TexturePixelDataType type) {
+            SizeT sizedPixelFormatSize = GetSizedTexturePixelDataTypeSize(type);
+            if (sizedPixelFormatSize > 0) return sizedPixelFormatSize;
+            return GetBaseTexturePixelDataTypeSize(type);
+        }
+
         SizeT GetInternalBytesPerPixel(TextureInternalFormat internalformat, TexturePixelDataType type) {
             SizeT sizedTextureFormatSize = GetSizedInternalFormatSizeInBytes(internalformat);
             if (sizedTextureFormatSize > 0) return sizedTextureFormatSize;

MobileGL/MG_Util/Metrics/TextureMetrics.h

@@ -16,6 +16,7 @@ namespace MobileGL {
         SizeT GetBaseInternalFormatComponentCount(TextureInternalFormat format);
         SizeT GetSizedTexturePixelDataTypeSize(TexturePixelDataType type);
         SizeT GetBaseTexturePixelDataTypeSize(TexturePixelDataType type);
+        SizeT GetTexturePixelDataTypeSize(TexturePixelDataType type);
         // This should respect internal format more
         SizeT GetInternalBytesPerPixel(TextureInternalFormat internalformat, TexturePixelDataType type);
         // This should respect type more, representing data passed in