fix(rhi): make opengl descriptor binding set-aware

tests/RHI/integration/sphere/main.cpp

@@ -122,10 +122,10 @@ MatrixBufferData CreateMatrixBufferData() {
 }
 
 const char kSphereHlsl[] = R"(
-Texture2D gDiffuseTexture : register(t0);
-SamplerState gSampler : register(s0);
+Texture2D gDiffuseTexture : register(t1);
+SamplerState gSampler : register(s1);
 
-cbuffer MatrixBuffer : register(b0) {
+cbuffer MatrixBuffer : register(b1) {
     float4x4 gProjectionMatrix;
     float4x4 gViewMatrix;
     float4x4 gModelMatrix;
@@ -159,7 +159,7 @@ const char kSphereVertexShader[] = R"(#version 430
 layout(location = 0) in vec4 aPosition;
 layout(location = 1) in vec2 aTexCoord;
 
-layout(std140, binding = 0) uniform MatrixBuffer {
+layout(std140, binding = 1) uniform MatrixBuffer {
     mat4 gProjectionMatrix;
     mat4 gViewMatrix;
     mat4 gModelMatrix;
@@ -176,7 +176,7 @@ void main() {
 )";
 
 const char kSphereFragmentShader[] = R"(#version 430
-layout(binding = 0) uniform sampler2D uTexture;
+layout(binding = 1) uniform sampler2D uTexture;
 
 in vec2 vTexCoord;
 
@@ -454,8 +454,24 @@ void SphereTest::InitializeSphereResources() {
     ASSERT_NE(mSamplerSet, nullptr);
     mSamplerSet->UpdateSampler(0, mSampler);
 
+    DescriptorSetLayoutBinding reservedSetBindings[3] = {};
+    reservedSetBindings[0].binding = 0;
+    reservedSetBindings[0].type = static_cast<uint32_t>(DescriptorType::CBV);
+    reservedSetBindings[0].count = 1;
+    reservedSetBindings[1].binding = 0;
+    reservedSetBindings[1].type = static_cast<uint32_t>(DescriptorType::SRV);
+    reservedSetBindings[1].count = 1;
+    reservedSetBindings[2].binding = 0;
+    reservedSetBindings[2].type = static_cast<uint32_t>(DescriptorType::Sampler);
+    reservedSetBindings[2].count = 1;
+
+    DescriptorSetLayoutDesc reservedLayoutDesc = {};
+    reservedLayoutDesc.bindings = reservedSetBindings;
+    reservedLayoutDesc.bindingCount = 3;
+
     DescriptorSetLayoutDesc setLayouts[kSphereDescriptorSetCount] = {};
-    // Reserve set0 so the integration test exercises non-zero firstSet binding.
+    // Reserve slot0 so the bound sets land on binding point 1 for every descriptor class.
+    setLayouts[0] = reservedLayoutDesc;
     setLayouts[1] = constantLayoutDesc;
     setLayouts[2] = textureLayoutDesc;
     setLayouts[3] = samplerLayoutDesc;

tests/RHI/unit/test_pipeline_layout.cpp

@@ -362,3 +362,59 @@ TEST_P(RHITestFixture, PipelineLayout_D3D12SeparatesOverlappingBindingsAcrossSet
     layout->Shutdown();
     delete layout;
 }
+
+TEST_P(RHITestFixture, PipelineLayout_OpenGLSeparatesOverlappingBindingsAcrossSetSlots) {
+    if (GetBackendType() != RHIType::OpenGL) {
+        GTEST_SKIP() << "OpenGL-specific binding point verification";
+    }
+
+    DescriptorSetLayoutBinding set0Bindings[3] = {};
+    set0Bindings[0].binding = 0;
+    set0Bindings[0].type = static_cast<uint32_t>(DescriptorType::CBV);
+    set0Bindings[0].count = 1;
+    set0Bindings[1].binding = 0;
+    set0Bindings[1].type = static_cast<uint32_t>(DescriptorType::SRV);
+    set0Bindings[1].count = 1;
+    set0Bindings[2].binding = 0;
+    set0Bindings[2].type = static_cast<uint32_t>(DescriptorType::Sampler);
+    set0Bindings[2].count = 1;
+
+    DescriptorSetLayoutBinding set1Bindings[3] = {};
+    set1Bindings[0].binding = 0;
+    set1Bindings[0].type = static_cast<uint32_t>(DescriptorType::CBV);
+    set1Bindings[0].count = 1;
+    set1Bindings[1].binding = 0;
+    set1Bindings[1].type = static_cast<uint32_t>(DescriptorType::SRV);
+    set1Bindings[1].count = 1;
+    set1Bindings[2].binding = 0;
+    set1Bindings[2].type = static_cast<uint32_t>(DescriptorType::Sampler);
+    set1Bindings[2].count = 1;
+
+    DescriptorSetLayoutDesc setLayouts[2] = {};
+    setLayouts[0].bindings = set0Bindings;
+    setLayouts[0].bindingCount = 3;
+    setLayouts[1].bindings = set1Bindings;
+    setLayouts[1].bindingCount = 3;
+
+    RHIPipelineLayoutDesc desc = {};
+    desc.setLayouts = setLayouts;
+    desc.setLayoutCount = 2;
+
+    RHIPipelineLayout* layout = GetDevice()->CreatePipelineLayout(desc);
+    ASSERT_NE(layout, nullptr);
+
+    auto* openGLLayout = static_cast<OpenGLPipelineLayout*>(layout);
+    EXPECT_TRUE(openGLLayout->UsesSetLayouts());
+    EXPECT_EQ(openGLLayout->GetSetLayoutCount(), 2u);
+    EXPECT_TRUE(openGLLayout->HasConstantBufferBinding(0, 0));
+    EXPECT_TRUE(openGLLayout->HasConstantBufferBinding(1, 0));
+    EXPECT_EQ(openGLLayout->GetConstantBufferBindingPoint(0, 0), 0u);
+    EXPECT_EQ(openGLLayout->GetConstantBufferBindingPoint(1, 0), 1u);
+    EXPECT_EQ(openGLLayout->GetShaderResourceBindingPoint(0, 0), 0u);
+    EXPECT_EQ(openGLLayout->GetShaderResourceBindingPoint(1, 0), 1u);
+    EXPECT_EQ(openGLLayout->GetSamplerBindingPoint(0, 0), 0u);
+    EXPECT_EQ(openGLLayout->GetSamplerBindingPoint(1, 0), 1u);
+
+    layout->Shutdown();
+    delete layout;
+}

tests/TEST_SPEC.md

@@ -175,6 +175,7 @@ tests/RHI/integration/
 5. 两个后端都必须与同一张 `GT.ppm` 做比对。
 6. 新测试如果暴露抽象层缺口，应先补 RHI，再补测试。
 7. 至少保留一个场景覆盖 `firstSet != 0` 的描述符绑定路径，当前由 `sphere` 负责验证。
+8. `sphere` 需要通过预留 `set0` 把实际 shader 绑定点推进到 `binding = 1`，避免出现“忽略 set 语义也能误通过”的假阳性。
 
 ### 6.3 命名