Complete ES 3.1 and 3.2 helpers

Which didn't handle indirect drawing, compute and tessellation
Since ES 3.1/3.2 don't provide API for glShaderStorageBlockBinding,
code was adjusted to use the default binding points and not require
that API.

Change-Id: Ie4dcd05f0a1d72e4a25f49b5fae138dc605ba5e3
Task-number: QTBUG-70660
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

7 files changed, 208 insertions, 3 deletions

diff --git a/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_1.cpp b/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_1.cpp
index 135e83aec..a555b67ef 100644
--- a/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_1.cpp
+++ b/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_1.cpp
@@ -53,10 +53,114 @@ QT_BEGIN_NAMESPACE
 #ifndef GL_UNSIGNED_INT_SAMPLER_2D_MULTISAMPLE
 #define GL_UNSIGNED_INT_SAMPLER_2D_MULTISAMPLE 0x910A
 #endif
+#ifndef GL_ACTIVE_RESOURCES
+#define GL_ACTIVE_RESOURCES 0x92F5
+#endif
+#ifndef GL_BUFFER_BINDING
+#define GL_BUFFER_BINDING 0x9302
+#endif
+#ifndef GL_BUFFER_DATA_SIZE
+#define GL_BUFFER_DATA_SIZE 0x9303
+#endif
+#ifndef GL_NUM_ACTIVE_VARIABLES
+#define GL_NUM_ACTIVE_VARIABLES 0x9304
+#endif
+#ifndef GL_SHADER_STORAGE_BLOCK
+#define GL_SHADER_STORAGE_BLOCK 0x92E6
+#endif
+#ifndef GL_ALL_BARRIER_BITS
+#define GL_ALL_BARRIER_BITS 0xFFFFFFFF
+#endif
+#ifndef GL_VERTEX_ATTRIB_ARRAY_BARRIER_BIT
+#define GL_VERTEX_ATTRIB_ARRAY_BARRIER_BIT 0x00000001
+#endif
+#ifndef GL_ELEMENT_ARRAY_BARRIER_BIT
+#define GL_ELEMENT_ARRAY_BARRIER_BIT 0x00000002
+#endif
+#ifndef GL_UNIFORM_BARRIER_BIT
+#define GL_UNIFORM_BARRIER_BIT 0x00000004
+#endif
+#ifndef GL_TEXTURE_FETCH_BARRIER_BIT
+#define GL_TEXTURE_FETCH_BARRIER_BIT 0x00000008
+#endif
+#ifndef GL_SHADER_IMAGE_ACCESS_BARRIER_BIT
+#define GL_SHADER_IMAGE_ACCESS_BARRIER_BIT 0x00000020
+#endif
+#ifndef GL_COMMAND_BARRIER_BIT
+#define GL_COMMAND_BARRIER_BIT 0x00000040
+#endif
+#ifndef GL_PIXEL_BUFFER_BARRIER_BIT
+#define GL_PIXEL_BUFFER_BARRIER_BIT 0x00000080
+#endif
+#ifndef GL_TEXTURE_UPDATE_BARRIER_BIT
+#define GL_TEXTURE_UPDATE_BARRIER_BIT 0x00000100
+#endif
+#ifndef GL_BUFFER_UPDATE_BARRIER_BIT
+#define GL_BUFFER_UPDATE_BARRIER_BIT 0x00000200
+#endif
+#ifndef GL_FRAMEBUFFER_BARRIER_BIT
+#define GL_FRAMEBUFFER_BARRIER_BIT 0x00000400
+#endif
+#ifndef GL_TRANSFORM_FEEDBACK_BARRIER_BIT
+#define GL_TRANSFORM_FEEDBACK_BARRIER_BIT 0x00000800
+#endif
+#ifndef GL_ATOMIC_COUNTER_BARRIER_BIT
+#define GL_ATOMIC_COUNTER_BARRIER_BIT 0x00001000
+#endif
+#ifndef GL_SHADER_STORAGE_BARRIER_BIT
+#define GL_SHADER_STORAGE_BARRIER_BIT 0x00002000
+#endif
+
 
 namespace Qt3DRender {
 namespace Render {
 
+namespace {
+
+GLbitfield memoryBarrierGLBitfield(QMemoryBarrier::Operations barriers)
+{
+    GLbitfield bits = 0;
+
+    if (barriers.testFlag(QMemoryBarrier::All)) {
+        bits |= GL_ALL_BARRIER_BITS;
+        return bits;
+    }
+
+    if (barriers.testFlag(QMemoryBarrier::VertexAttributeArray))
+        bits |= GL_VERTEX_ATTRIB_ARRAY_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::ElementArray))
+        bits |= GL_ELEMENT_ARRAY_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::Uniform))
+        bits |= GL_UNIFORM_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::TextureFetch))
+        bits |= GL_TEXTURE_FETCH_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::ShaderImageAccess))
+        bits |= GL_SHADER_IMAGE_ACCESS_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::Command))
+        bits |= GL_COMMAND_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::PixelBuffer))
+        bits |= GL_PIXEL_BUFFER_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::TextureUpdate))
+        bits |= GL_TEXTURE_UPDATE_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::BufferUpdate))
+        bits |= GL_BUFFER_UPDATE_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::FrameBuffer))
+        bits |= GL_FRAMEBUFFER_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::TransformFeedback))
+        bits |= GL_TRANSFORM_FEEDBACK_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::AtomicCounter))
+        bits |= GL_ATOMIC_COUNTER_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::ShaderStorage))
+        bits |= GL_SHADER_STORAGE_BARRIER_BIT;
+    if (barriers.testFlag(QMemoryBarrier::QueryBuffer))
+        qWarning() << "QueryBuffer barrier not supported by ES 3.1";
+
+    return bits;
+}
+
+} // anonymous
+
+
 GraphicsHelperES3_1::GraphicsHelperES3_1()
 {
 }
@@ -65,6 +169,70 @@ GraphicsHelperES3_1::~GraphicsHelperES3_1()
 {
 }
 
+bool GraphicsHelperES3_1::supportsFeature(GraphicsHelperInterface::Feature feature) const
+{
+    switch (feature) {
+    case GraphicsHelperInterface::Compute:
+    case GraphicsHelperInterface::ShaderStorageObject:
+    case GraphicsHelperInterface::IndirectDrawing:
+        return true;
+    default:
+        break;
+    }
+    return GraphicsHelperES3::supportsFeature(feature);
+}
+
+void GraphicsHelperES3_1::dispatchCompute(GLuint wx, GLuint wy, GLuint wz)
+{
+    m_extraFuncs->glDispatchCompute(wx, wy, wz);
+}
+
+void GraphicsHelperES3_1::memoryBarrier(QMemoryBarrier::Operations barriers)
+{
+    m_extraFuncs->glMemoryBarrier(memoryBarrierGLBitfield(barriers));
+}
+
+void GraphicsHelperES3_1::drawArraysIndirect(GLenum mode, void *indirect)
+{
+    m_extraFuncs->glDrawArraysIndirect(mode, indirect);
+}
+
+void GraphicsHelperES3_1::drawElementsIndirect(GLenum mode, GLenum type, void *indirect)
+{
+    m_extraFuncs->glDrawElementsIndirect(mode, type, indirect);
+}
+
+void GraphicsHelperES3_1::bindShaderStorageBlock(GLuint , GLuint , GLuint )
+{
+    // ES 3.1 has no API for that, bindings have to be specified directly in the shader
+    // with layout(std430, binding = 3)
+    qWarning() << "ES 3.1 has no bindShaderStorageBlock API, it uses binding declaration from the shader storage block";
+}
+
+QVector<ShaderStorageBlock> GraphicsHelperES3_1::programShaderStorageBlocks(GLuint programId)
+{
+    QVector<ShaderStorageBlock> blocks;
+    GLint nbrActiveShaderStorageBlocks = 0;
+    m_extraFuncs->glGetProgramInterfaceiv(programId, GL_SHADER_STORAGE_BLOCK, GL_ACTIVE_RESOURCES, &nbrActiveShaderStorageBlocks);
+    blocks.reserve(nbrActiveShaderStorageBlocks);
+    for (GLint i = 0; i < nbrActiveShaderStorageBlocks; ++i) {
+        QByteArray storageBlockName(256, '\0');
+        GLsizei length = 0;
+        ShaderStorageBlock storageBlock;
+        m_extraFuncs->glGetProgramResourceName(programId, GL_SHADER_STORAGE_BLOCK, i, 256, &length, storageBlockName.data());
+        storageBlock.m_index = i;
+        storageBlock.m_name = QString::fromUtf8(storageBlockName.left(length));
+        GLenum prop = GL_BUFFER_BINDING;
+        m_extraFuncs->glGetProgramResourceiv(programId, GL_SHADER_STORAGE_BLOCK, i, 1, &prop, 4, NULL, &storageBlock.m_binding);
+        prop = GL_BUFFER_DATA_SIZE;
+        m_extraFuncs->glGetProgramResourceiv(programId, GL_SHADER_STORAGE_BLOCK, i, 1, &prop, 4, NULL, &storageBlock.m_size);
+        prop = GL_NUM_ACTIVE_VARIABLES;
+        m_extraFuncs->glGetProgramResourceiv(programId, GL_SHADER_STORAGE_BLOCK, i, 1, &prop, 4, NULL, &storageBlock.m_activeVariablesCount);
+        blocks.push_back(storageBlock);
+    }
+    return blocks;
+}
+
 UniformType GraphicsHelperES3_1::uniformTypeFromGLType(GLenum glType)
 {
     switch (glType) {
diff --git a/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_1_p.h b/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_1_p.h
index 70a584380..2c130fbf5 100644
--- a/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_1_p.h
+++ b/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_1_p.h
@@ -64,6 +64,14 @@ public:
     GraphicsHelperES3_1();
     ~GraphicsHelperES3_1();
 
+    bool supportsFeature(Feature feature) const override;
+    void dispatchCompute(GLuint wx, GLuint wy, GLuint wz) override;
+    void memoryBarrier(QMemoryBarrier::Operations barriers) override;
+    void drawArraysIndirect(GLenum mode,void *indirect) override;
+    void drawElementsIndirect(GLenum mode, GLenum type, void *indirect) override;
+    void bindShaderStorageBlock(GLuint programId, GLuint shaderStorageBlockIndex, GLuint shaderStorageBlockBinding) override;
+    QVector<ShaderStorageBlock> programShaderStorageBlocks(GLuint programId) override;
+
     // QGraphicHelperInterface interface
     UniformType uniformTypeFromGLType(GLenum glType) override;
     uint uniformByteSize(const ShaderUniform &description) override;
diff --git a/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_2.cpp b/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_2.cpp
index 6290d091d..9dce08e4f 100644
--- a/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_2.cpp
+++ b/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_2.cpp
@@ -52,6 +52,10 @@ QT_BEGIN_NAMESPACE
 #define GL_DEPTH_STENCIL_ATTACHMENT       0x821A
 #endif
 
+#ifndef GL_PATCH_VERTICES
+#define GL_PATCH_VERTICES 36466
+#endif
+
 namespace Qt3DRender {
 namespace Render {
 
@@ -63,6 +67,17 @@ GraphicsHelperES3_2::~GraphicsHelperES3_2()
 {
 }
 
+bool GraphicsHelperES3_2::supportsFeature(GraphicsHelperInterface::Feature feature) const
+{
+    switch (feature) {
+    case GraphicsHelperInterface::Tessellation:
+        return true;
+    default:
+        break;
+    }
+    return GraphicsHelperES3_1::supportsFeature(feature);
+}
+
 bool GraphicsHelperES3_2::frameBufferNeedsRenderBuffer(const Attachment &attachment)
 {
     Q_UNUSED(attachment);
@@ -97,6 +112,11 @@ void GraphicsHelperES3_2::bindFrameBufferAttachment(QOpenGLTexture *texture, con
     texture->release();
 }
 
+void GraphicsHelperES3_2::setVerticesPerPatch(GLint verticesPerPatch)
+{
+    m_extraFuncs->glPatchParameteri(GL_PATCH_VERTICES, verticesPerPatch);
+}
+
 } // namespace Render
 } // namespace Qt3DRender
 
diff --git a/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_2_p.h b/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_2_p.h
index 787bba5f0..ed71b1e3e 100644
--- a/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_2_p.h
+++ b/src/render/renderers/opengl/graphicshelpers/graphicshelperes3_2_p.h
@@ -64,9 +64,12 @@ public:
     GraphicsHelperES3_2();
     ~GraphicsHelperES3_2();
 
+    bool supportsFeature(Feature feature) const override;
+
     // QGraphicHelperInterface interface
     void bindFrameBufferAttachment(QOpenGLTexture *texture, const Attachment &attachment) override;
     bool frameBufferNeedsRenderBuffer(const Attachment &attachment) override;
+    void setVerticesPerPatch(GLint verticesPerPatch) override;
 };
 
 } // namespace Render
diff --git a/src/render/renderers/opengl/graphicshelpers/submissioncontext.cpp b/src/render/renderers/opengl/graphicshelpers/submissioncontext.cpp
index 7bb0713ee..26ee94305 100644
--- a/src/render/renderers/opengl/graphicshelpers/submissioncontext.cpp
+++ b/src/render/renderers/opengl/graphicshelpers/submissioncontext.cpp
@@ -1291,15 +1291,19 @@ bool SubmissionContext::setParameters(ShaderParameterPack &parameterPack)
 
     // Bind Shader Storage block to SSBO and update SSBO
     const QVector<BlockToSSBO> blockToSSBOs = parameterPack.shaderStorageBuffers();
-    int ssboIndex = 0;
     for (const BlockToSSBO b : blockToSSBOs) {
         Buffer *cpuBuffer = m_renderer->nodeManagers()->bufferManager()->lookupResource(b.m_bufferID);
         GLBuffer *ssbo = glBufferForRenderBuffer(cpuBuffer, GLBuffer::ShaderStorageBuffer);
-        bindShaderStorageBlock(shader->programId(), b.m_blockIndex, ssboIndex);
+
+        // bindShaderStorageBlock
+        // This is currently not required as we are introspecting the bindingIndex
+        // value from the shaders and not replacing them, making such a call useless
+        // bindShaderStorageBlock(shader->programId(), b.m_blockIndex, b.m_bindingIndex);
+
         // Needed to avoid conflict where the buffer would already
         // be bound as a VertexArray
         bindGLBuffer(ssbo, GLBuffer::ShaderStorageBuffer);
-        ssbo->bindBufferBase(this, ssboIndex++, GLBuffer::ShaderStorageBuffer);
+        ssbo->bindBufferBase(this, b.m_bindingIndex, GLBuffer::ShaderStorageBuffer);
         // TO DO: Make sure that there's enough binding points
     }
 
diff --git a/src/render/renderers/opengl/renderer/renderview.cpp b/src/render/renderers/opengl/renderer/renderview.cpp
index c29448570..66299e430 100644
--- a/src/render/renderers/opengl/renderer/renderview.cpp
+++ b/src/render/renderers/opengl/renderer/renderview.cpp
@@ -884,6 +884,7 @@ void RenderView::setShaderStorageValue(ShaderParameterPack &uniformPack,
             BlockToSSBO shaderStorageBlock;
             shaderStorageBlock.m_blockIndex = block.m_index;
             shaderStorageBlock.m_bufferID = buffer->peerId();
+            shaderStorageBlock.m_bindingIndex = block.m_binding;
             uniformPack.setShaderStorageBuffer(shaderStorageBlock);
             // Buffer update to GL buffer will be done at render time
         }
diff --git a/src/render/renderers/opengl/renderer/shaderparameterpack_p.h b/src/render/renderers/opengl/renderer/shaderparameterpack_p.h
index 5703bb17b..fe9ab3995 100644
--- a/src/render/renderers/opengl/renderer/shaderparameterpack_p.h
+++ b/src/render/renderers/opengl/renderer/shaderparameterpack_p.h
@@ -83,6 +83,7 @@ QT3D_DECLARE_TYPEINFO_2(Qt3DRender, Render, BlockToUBO, Q_MOVABLE_TYPE)
 
 struct BlockToSSBO {
     int m_blockIndex;
+    int m_bindingIndex;
     Qt3DCore::QNodeId m_bufferID;
 };
 QT3D_DECLARE_TYPEINFO_2(Qt3DRender, Render, BlockToSSBO, Q_PRIMITIVE_TYPE)