Enable the GL_EXT_geometry_shader extension where necessary

Bug: skia:
Change-Id: I37bfb90efed28748d6c3e53be5c9703c291b036c
Reviewed-on: https://skia-review.googlesource.com/93460
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>

6 files changed, 68 insertions, 7 deletions

diff --git a/include/gpu/GrShaderCaps.h b/include/gpu/GrShaderCaps.h
index 82fd077592..b56694c7dc 100644
--- a/include/gpu/GrShaderCaps.h
+++ b/include/gpu/GrShaderCaps.h
@@ -139,6 +139,14 @@ public:
         return fShaderDerivativeExtensionString;
     }
 
+    // Returns the string of an extension that must be enabled in the shader to support geometry
+    // shaders. If nullptr is returned then no extension needs to be enabled. Before calling this
+    // function, the caller must verify that geometryShaderSupport exists.
+    const char* geometryShaderExtensionString() const {
+        SkASSERT(this->geometryShaderSupport());
+        return fGeometryShaderExtensionString;
+    }
+
     // Returns the string of an extension that must be enabled in the shader to support
     // geometry shader invocations. If nullptr is returned then no extension needs to be enabled.
     // Before calling this function, the caller must verify that gsInvocationsSupport exists.
@@ -271,6 +279,7 @@ private:
     const char* fVersionDeclString;
 
     const char* fShaderDerivativeExtensionString;
+    const char* fGeometryShaderExtensionString;
     const char* fGSInvocationsExtensionString;
     const char* fFragCoordConventionsExtensionString;
     const char* fSecondaryOutputExtensionString;
diff --git a/src/gpu/GrShaderCaps.cpp b/src/gpu/GrShaderCaps.cpp
index e232f3d826..2041ada635 100644
--- a/src/gpu/GrShaderCaps.cpp
+++ b/src/gpu/GrShaderCaps.cpp
@@ -52,6 +52,7 @@ GrShaderCaps::GrShaderCaps(const GrContextOptions& options) {
 
     fVersionDeclString = nullptr;
     fShaderDerivativeExtensionString = nullptr;
+    fGeometryShaderExtensionString = nullptr;
     fGSInvocationsExtensionString = nullptr;
     fFragCoordConventionsExtensionString = nullptr;
     fSecondaryOutputExtensionString = nullptr;
diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index 038a1b1a73..4996859c51 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -331,14 +331,18 @@ void GrGLCaps::init(const GrContextOptions& contextOptions,
 
         shaderCaps->fIntegerSupport = ctxInfo.version() >= GR_GL_VER(3, 0) &&
             ctxInfo.glslGeneration() >= k130_GrGLSLGeneration;
-    }
-    else {
+    } else {
         shaderCaps->fDualSourceBlendingSupport = ctxInfo.hasExtension("GL_EXT_blend_func_extended");
 
         shaderCaps->fShaderDerivativeSupport = ctxInfo.version() >= GR_GL_VER(3, 0) ||
             ctxInfo.hasExtension("GL_OES_standard_derivatives");
 
-        shaderCaps->fGeometryShaderSupport = ctxInfo.hasExtension("GL_EXT_geometry_shader");
+        if (ctxInfo.version() >= GR_GL_VER(3,2)) {
+            shaderCaps->fGeometryShaderSupport = true;
+        } else if (ctxInfo.hasExtension("GL_EXT_geometry_shader")) {
+            shaderCaps->fGeometryShaderSupport = true;
+            shaderCaps->fGeometryShaderExtensionString = "GL_EXT_geometry_shader";
+        }
         if (shaderCaps->fGeometryShaderSupport && kQualcomm_GrGLDriver == ctxInfo.driver()) {
             // Qualcomm driver @103.0 has been observed to crash compiling ccpr geometry shaders.
             // @127.0 is the earliest verified driver to not crash.
diff --git a/src/sksl/SkSLGLSLCodeGenerator.cpp b/src/sksl/SkSLGLSLCodeGenerator.cpp
index ad3fde52f9..9e2336e22e 100644
--- a/src/sksl/SkSLGLSLCodeGenerator.cpp
+++ b/src/sksl/SkSLGLSLCodeGenerator.cpp
@@ -1246,6 +1246,12 @@ bool GLSLCodeGenerator::generateCode() {
     fOut = &fHeader;
     fProgramKind = fProgram.fKind;
     this->writeHeader();
+    if (Program::kGeometry_Kind == fProgramKind &&
+        fProgram.fSettings.fCaps->geometryShaderExtensionString()) {
+        fHeader.writeText("#extension ");
+        fHeader.writeText(fProgram.fSettings.fCaps->geometryShaderExtensionString());
+        fHeader.writeText(" : require\n");
+    }
     StringStream body;
     fOut = &body;
     for (const auto& e : fProgram.fElements) {
diff --git a/src/sksl/SkSLUtil.h b/src/sksl/SkSLUtil.h
index 1d9d53f6e8..7a39386269 100644
--- a/src/sksl/SkSLUtil.h
+++ b/src/sksl/SkSLUtil.h
@@ -155,6 +155,10 @@ public:
         return nullptr;
     }
 
+    const char* geometryShaderExtensionString() const {
+        return nullptr;
+    }
+
     const char* gsInvocationsExtensionString() const {
         return nullptr;
     }
@@ -184,7 +188,6 @@ public:
         sk_sp<GrShaderCaps> result = sk_make_sp<GrShaderCaps>(GrContextOptions());
         result->fVersionDeclString = "#version 400";
         result->fShaderDerivativeSupport = true;
-        result->fGSInvocationsSupport = true;
         return result;
     }
 
@@ -253,6 +256,14 @@ public:
         return result;
     }
 
+    static sk_sp<GrShaderCaps> GeometryShaderSupport() {
+        sk_sp<GrShaderCaps> result = sk_make_sp<GrShaderCaps>(GrContextOptions());
+        result->fVersionDeclString = "#version 400";
+        result->fGeometryShaderSupport = true;
+        result->fGSInvocationsSupport = true;
+        return result;
+    }
+
     static sk_sp<GrShaderCaps> NoGSInvocationsSupport() {
         sk_sp<GrShaderCaps> result = sk_make_sp<GrShaderCaps>(GrContextOptions());
         result->fVersionDeclString = "#version 400";
@@ -261,6 +272,15 @@ public:
         return result;
     }
 
+    static sk_sp<GrShaderCaps> GeometryShaderExtensionString() {
+        sk_sp<GrShaderCaps> result = sk_make_sp<GrShaderCaps>(GrContextOptions());
+        result->fVersionDeclString = "#version 310es";
+        result->fGeometryShaderSupport = true;
+        result->fGeometryShaderExtensionString = "GL_EXT_geometry_shader";
+        result->fGSInvocationsSupport = true;
+        return result;
+    }
+
     static sk_sp<GrShaderCaps> GSInvocationsExtensionString() {
         sk_sp<GrShaderCaps> result = sk_make_sp<GrShaderCaps>(GrContextOptions());
         result->fVersionDeclString = "#version 400";
diff --git a/tests/SkSLGLSLTest.cpp b/tests/SkSLGLSLTest.cpp
index 7c69de62be..1ae421f8af 100644
--- a/tests/SkSLGLSLTest.cpp
+++ b/tests/SkSLGLSLTest.cpp
@@ -1146,7 +1146,7 @@ DEF_TEST(SkSLGeometry, r) {
          "EmitVertex();"
          "EndPrimitive();"
          "}",
-         *SkSL::ShaderCapsFactory::Default(),
+         *SkSL::ShaderCapsFactory::GeometryShaderSupport(),
          "#version 400\n"
          "layout (points) in ;\n"
          "layout (invocations = 2) in ;\n"
@@ -1485,7 +1485,7 @@ DEF_TEST(SkSLDeadLoopVar, r) {
          );
 }
 
-DEF_TEST(SkSLInvocations, r) {
+DEF_TEST(SkSLGeometryShaders, r) {
     test(r,
          "layout(points) in;"
          "layout(invocations = 2) in;"
@@ -1539,6 +1539,27 @@ DEF_TEST(SkSLInvocations, r) {
          "    EndPrimitive();\n"
          "}\n",
          SkSL::Program::kGeometry_Kind);
+    test(r,
+         "layout(points, invocations = 2) in;"
+         "layout(invocations = 3) in;"
+         "layout(line_strip, max_vertices = 2) out;"
+         "void main() {"
+         "sk_Position = sk_in[0].sk_Position + float4(-0.5, 0, 0, sk_InvocationID);"
+         "EmitVertex();"
+         "EndPrimitive();"
+         "}",
+         *SkSL::ShaderCapsFactory::GeometryShaderExtensionString(),
+         "#version 310es\n"
+         "#extension GL_EXT_geometry_shader : require\n"
+         "layout (points, invocations = 2) in ;\n"
+         "layout (invocations = 3) in ;\n"
+         "layout (line_strip, max_vertices = 2) out ;\n"
+         "void main() {\n"
+         "    gl_Position = gl_in[0].gl_Position + vec4(-0.5, 0.0, 0.0, float(gl_InvocationID));\n"
+         "    EmitVertex();\n"
+         "    EndPrimitive();\n"
+         "}\n",
+         SkSL::Program::kGeometry_Kind);
 }
 
 DEF_TEST(SkSLTypePrecision, r) {
@@ -1719,7 +1740,7 @@ DEF_TEST(SkSLNormalization, r) {
          "EmitVertex();"
          "EndPrimitive();"
          "}",
-         *SkSL::ShaderCapsFactory::Default(),
+         *SkSL::ShaderCapsFactory::GeometryShaderSupport(),
          "#version 400\n"
          "uniform vec4 sk_RTAdjust;\n"
          "layout (points) in ;\n"