Fix some ES2 issues

Fix specification of mipmaps when generating textures.

Fix oversight where emulated UBOs would not replace uniforms when swapped out
for another.

NEW_RELEASE_NOTES.md

@@ -8,3 +8,4 @@ appropriate header in [RELEASE_NOTES.md](./RELEASE_NOTES.md).
 
 ## Release notes for next branch cut
 
+

RELEASE_NOTES.md

@@ -17,6 +17,7 @@ Instead, if you are authoring a PR for the main branch, add your release note to
 - engine: Add `Material::getFeatureLevel()`
 - engine: Add missing `Material::getReflectionMode()` method in Java
 - engine: Support basic usage of post-processing materials on feature level 0
+- engine: Fix critical GLES 2.0 bugs
 
 ## v1.45.1
 

filament/backend/src/opengl/OpenGLDriver.cpp

@@ -172,7 +172,7 @@ OpenGLDriver::OpenGLDriver(OpenGLPlatform* platform, const Platform::DriverConfi
           mShaderCompilerService(*this),
           mHandleAllocator("Handles", driverConfig.handleArenaSize),
           mSamplerMap(32) {
-  
+
     std::fill(mSamplerBindings.begin(), mSamplerBindings.end(), nullptr);
 
     // set a reasonable default value for our stream array
@@ -268,9 +268,9 @@ void OpenGLDriver::useProgram(OpenGLProgram* p) noexcept {
 
     if (UTILS_UNLIKELY(mContext.isES2())) {
         for (uint32_t i = 0; i < Program::UNIFORM_BINDING_COUNT; i++) {
-            auto [buffer, age] = mUniformBindings[i];
+            auto [id, buffer, age] = mUniformBindings[i];
             if (buffer) {
-                p->updateUniforms(i, buffer, age);
+                p->updateUniforms(i, id, buffer, age);
             }
         }
         // Set the output colorspace for this program (linear or rec709). This in only relevant
@@ -479,6 +479,7 @@ void OpenGLDriver::createBufferObjectR(Handle<HwBufferObject> boh,
 
     GLBufferObject* bo = construct<GLBufferObject>(boh, byteCount, bindingType, usage);
     if (UTILS_UNLIKELY(bindingType == BufferObjectBinding::UNIFORM && gl.isES2())) {
+        bo->gl.id = ++mLastAssignedEmulatedUboId;
         bo->gl.buffer = malloc(byteCount);
         memset(bo->gl.buffer, 0, byteCount);
     } else {
@@ -595,8 +596,9 @@ void OpenGLDriver::textureStorage(OpenGLDriver::GLTexture* t,
                         }
                     } else {
                         glTexImage2D(t->gl.target, level, GLint(t->gl.internalFormat),
-                                GLsizei(width), GLsizei(height), 0,
-                                format, type, nullptr);
+                                std::max(GLsizei(1), GLsizei(width >> level)),
+                                std::max(GLsizei(1), GLsizei(height >> level)),
+                                0, format, type, nullptr);
                     }
                 }
             }
@@ -2901,7 +2903,11 @@ void OpenGLDriver::bindBufferRange(BufferObjectBinding bindingType, uint32_t ind
     assert_invariant(offset + size <= ub->byteCount);
 
     if (UTILS_UNLIKELY(ub->bindingType == BufferObjectBinding::UNIFORM && gl.isES2())) {
-        mUniformBindings[index] = { static_cast<uint8_t const*>(ub->gl.buffer) + offset, ub->age };
+        mUniformBindings[index] = {
+                ub->gl.id,
+                static_cast<uint8_t const*>(ub->gl.buffer) + offset,
+                ub->age,
+        };
     } else {
         GLenum const target = GLUtils::getBufferBindingType(bindingType);
 

filament/backend/src/opengl/OpenGLDriver.h

@@ -83,11 +83,9 @@ public:
         }
 
         struct {
+            GLuint id;
             union {
-                struct {
-                    GLuint id;
-                    GLenum binding;
-                };
+                GLenum binding;
                 void* buffer;
             };
         } gl;
@@ -363,7 +361,8 @@ private:
     void setScissor(Viewport const& scissor) noexcept;
 
     // ES2 only. Uniform buffer emulation binding points
-    std::array<std::pair<void const*, uint16_t>, Program::UNIFORM_BINDING_COUNT> mUniformBindings = {};
+    GLuint mLastAssignedEmulatedUboId = 0;
+    std::array<std::tuple<GLuint, void const*, uint16_t>, Program::UNIFORM_BINDING_COUNT> mUniformBindings = {};
 
     // sampler buffer binding points (nullptr if not used)
     std::array<GLSamplerGroup*, Program::SAMPLER_BINDING_COUNT> mSamplerBindings = {};   // 4 pointers

filament/backend/src/opengl/OpenGLProgram.cpp

@@ -229,15 +229,16 @@ void OpenGLProgram::updateSamplers(OpenGLDriver* const gld) const noexcept {
     CHECK_GL_ERROR(utils::slog.e)
 }
 
-void OpenGLProgram::updateUniforms(uint32_t index, void const* buffer, uint16_t age) noexcept {
+void OpenGLProgram::updateUniforms(uint32_t index, GLuint id, void const* buffer, uint16_t age) noexcept {
     assert_invariant(mUniformsRecords);
     assert_invariant(buffer);
 
     // only update the uniforms if the UBO has changed since last time we updated
     UniformsRecord const& records = mUniformsRecords[index];
-    if (records.age == age) {
+    if (records.id == id && records.age == age) {
         return;
     }
+    records.id = id;
     records.age = age;
 
     assert_invariant(records.uniforms.size() == records.locations.size());

filament/backend/src/opengl/OpenGLProgram.h

@@ -72,7 +72,7 @@ public:
     } gl; // 12 bytes
 
     // For ES2 only
-    void updateUniforms(uint32_t index, void const* buffer, uint16_t age) noexcept;
+    void updateUniforms(uint32_t index, GLuint id, void const* buffer, uint16_t age) noexcept;
     void setRec709ColorSpace(bool rec709) const noexcept;
 
 private:
@@ -98,6 +98,7 @@ private:
     struct UniformsRecord {
         Program::UniformInfo uniforms;
         LocationInfo locations;
+        mutable GLuint id = 0;
         mutable uint16_t age = std::numeric_limits<uint16_t>::max();
     };
     UniformsRecord const* mUniformsRecords = nullptr;

filament/src/PostProcessManager.cpp

@@ -2714,7 +2714,8 @@ FrameGraphId<FrameGraphTexture> PostProcessManager::upscale(FrameGraph& fg, bool
         filament::Viewport const& vp, FrameGraphTexture::Descriptor const& outDesc,
         backend::SamplerMagFilter filter) noexcept {
 
-    if (UTILS_LIKELY(!translucent && dsrOptions.quality == QualityLevel::LOW)) {
+    if (UTILS_LIKELY(!translucent && dsrOptions.quality == QualityLevel::LOW &&
+            mEngine.getDriverApi().getFeatureLevel() >= FeatureLevel::FEATURE_LEVEL_1)) {
         return opaqueBlit(fg, input, vp, outDesc, filter);
     }
 

shaders/src/depth_main.fs

@@ -58,9 +58,9 @@ void main() {
     fragColor.zw = computeDepthMomentsVSM(-1.0 / depth); // requires at least RGBA16F
 #elif defined(VARIANT_HAS_PICKING)
 #if MATERIAL_FEATURE_LEVEL == 0
-    outPicking.a = float((object_uniforms_objectId / 65536) % 256) / 255.0;
-    outPicking.b = float((object_uniforms_objectId /   256) % 256) / 255.0;
-    outPicking.g = float( object_uniforms_objectId          % 256) / 255.0;
+    outPicking.a = mod(float(object_uniforms_objectId / 65536), 256.0) / 255.0;
+    outPicking.b = mod(float(object_uniforms_objectId /   256), 256.0) / 255.0;
+    outPicking.g = mod(float(object_uniforms_objectId)        , 256.0) / 255.0;
     outPicking.r = vertex_position.z / vertex_position.w;
 #else
     outPicking.x = intBitsToFloat(object_uniforms_objectId);