GL: implement EXT_clip_control and WEBGL_polygon_mode on Emscripten.

Following the spirit of extension-based functionality, the entrypoints are available always but do something (i.e., call the actual WebGL API) only if the extension is advertised. Which it is only on Emscripten 3.1.66+ because older versions don't have the corresponding entrypoints, so there it's marked as disabled. Additionally, EXT_polygon_offset_clamp is now also working on 3.1.66+, but there's no wrapper for it yet.
2 years ago · a95fdb5598
8 changed files with 99 additions and 51 deletions
--- a/doc/changelog.dox
+++ b/doc/changelog.dox
@ -129,8 +129,9 @@ See also:
    extensions on GLES 3.1+, exposed as @ref GL::Texture::view() and similar
    APIs on other texture types
 -   Implemented the GL 4.5 @gl_extension{ARB,clip_control} extension and
-    matching @gl_extension{EXT,clip_control} extension on GLES, exposed as
-    @ref GL::Renderer::setClipControl(). See also [mosra/magnum#543](https://github.com/mosra/magnum/issues/543).
+    matching @gl_extension{EXT,clip_control} and
+    @webgl_extension{WEBGL,clip_control} extension on GLES and WebGL, exposed
+    as @ref GL::Renderer::setClipControl(). See also [mosra/magnum#543](https://github.com/mosra/magnum/issues/543).
 -   Implemented @gl_extension{EXT,texture_norm16} and
    @webgl_extension{EXT,texture_norm16} ES and WebGL extensions, making
    normalized 16-bit texture and renderbuffer formats available on all
@ -156,18 +157,19 @@ See also:
    WebGL extensions, making @ref GL::SamplerWrapping::MirrorClampToEdge
    available on all platforms
 -   Implemented the @m_class{m-doc-external} [ANGLE_provoking_vertex](https://chromium.googlesource.com/angle/angle/+/main/extensions/ANGLE_provoking_vertex.txt)
-    and @m_class{m-doc-external} [ANGLE_polygon_mode](https://chromium.googlesource.com/angle/angle/+/HEAD/extensions/ANGLE_polygon_mode.txt)
-    ES extensions. Recognized also on WebGL as
-    @webgl_extension{WEBGL,provoking_vertex} and
-    @webgl_extension{WEBGL,polygon_mode} but with no implementation as
+    ES extension. Recognized also on WebGL as
+    @webgl_extension{WEBGL,provoking_vertex} but with no implementation as
    Emscripten doesn't have the required entrypoints yet.
+-   Implemented the @m_class{m-doc-external} [ANGLE_polygon_mode](https://chromium.googlesource.com/angle/angle/+/HEAD/extensions/ANGLE_polygon_mode.txt)
+    and @webgl_extension{WEBGL,polygon_mode} ES and WebGL extension.
 -   Implemented the @m_class{m-doc-external} [ANGLE_stencil_texturing](https://chromium.googlesource.com/angle/angle/+/HEAD/extensions/ANGLE_stencil_texturing.txt)
    ES and @webgl_extension{WEBGL,stencil_texturing} WebGL extensions
 -   Implemented the @gl_extension{EXT,blend_func_extended} ES and
    @webgl_extension{WEBGL,blend_func_extended} WebGL extensions
 -   Implemented the @gl_extension{INTEL,blackhole_render} desktop and ES
    extension
-   Recognizing @webgl_extension{EXT,float_blend} and
+-   Recognizing @webgl_extension{EXT,float_blend},
+    @webgl_extension{EXT,polygon_offset_clamp} and
    @webgl_extension{WEBGL,debug_shaders} WebGL extensions, no implementation
    done yet
 -   Implemented @ref GL-AbstractShaderProgram-async "Async shader compilation and linking"
--- a/doc/opengl-support.dox
+++ b/doc/opengl-support.dox
@ -576,7 +576,7 @@ Extension                                   | Status
@webgl_extension{EXT,texture_compression_bptc} | done
@webgl_extension{EXT,texture_norm16}        | done
@webgl_extension{EXT,polygon_offset_clamp}  | |
-@webgl_extension{EXT,clip_control}          | |
+@webgl_extension{EXT,clip_control}          | done
@webgl_extension{EXT,depth_clamp}           | done
@webgl_extension{EXT,texture_mirror_clamp_to_edge} | done
@webgl_extension{KHR,parallel_shader_compile} | done
@ -598,7 +598,7 @@ Extension                                   | Status
@webgl_extension{WEBGL,draw_instanced_base_vertex_base_instance} | done
@webgl_extension{WEBGL,multi_draw_instanced_base_vertex_base_instance} | done
@webgl_extension{WEBGL,provoking_vertex}    | missing support in Emscripten
-@webgl_extension{WEBGL,polygon_mode}        | |
+@webgl_extension{WEBGL,polygon_mode}        | done
@webgl_extension{WEBGL,blend_func_extended} | done
@webgl_extension{WEBGL,stencil_texturing}   | done

--- a/src/Magnum/GL/Implementation/RendererState.cpp
+++ b/src/Magnum/GL/Implementation/RendererState.cpp
@ -31,6 +31,16 @@
 #include "Magnum/GL/Context.h"
 #include "Magnum/GL/Extensions.h"

+/* The __EMSCRIPTEN_major__ etc macros used to be passed implicitly, version
+   3.1.4 moved them to a version header and version 3.1.23 dropped the
+   backwards compatibility. To work consistently on all versions, including the
+   header only if the version macros aren't present.
+   https://github.com/emscripten-core/emscripten/commit/f99af02045357d3d8b12e63793cef36dfde4530a
+   https://github.com/emscripten-core/emscripten/commit/f76ddc702e4956aeedb658c49790cc352f892e4c */
+#if defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(__EMSCRIPTEN_major__)
+#include <emscripten/version.h>
+#endif
+
 namespace Magnum { namespace GL { namespace Implementation {

 using namespace Containers::Literals;
@ -206,7 +216,8 @@ RendererState::RendererState(Context& context, ContextState& contextState, Conta
    #endif
    #endif

-    #if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_WEBGL)
+    #ifdef MAGNUM_TARGET_GLES
+    #ifndef MAGNUM_TARGET_WEBGL
    if(context.isExtensionSupported<Extensions::NV::polygon_mode>()) {
        extensions[Extensions::NV::polygon_mode::Index] =
                   Extensions::NV::polygon_mode::string();
@ -215,7 +226,15 @@ RendererState::RendererState(Context& context, ContextState& contextState, Conta
        extensions[Extensions::ANGLE::polygon_mode::Index] =
                   Extensions::ANGLE::polygon_mode::string();
        polygonModeImplementation = glPolygonModeANGLE;
-    } else {
+    } else
+    #elif __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ >= 30166
+    if(context.isExtensionSupported<Extensions::WEBGL::polygon_mode>()) {
+        extensions[Extensions::WEBGL::polygon_mode::Index] =
+                   Extensions::WEBGL::polygon_mode::string();
+        polygonModeImplementation = glPolygonModeWEBGL;
+    } else
+    #endif
+    {
        polygonModeImplementation = nullptr;
    }
    #endif
--- a/src/Magnum/GL/Implementation/RendererState.h
+++ b/src/Magnum/GL/Implementation/RendererState.h
@ -59,7 +59,7 @@ struct RendererState {
    void(APIENTRY *blendFuncSeparateiImplementation)(GLuint, GLenum, GLenum, GLenum, GLenum);
    void(APIENTRY *colorMaskiImplementation)(GLuint, GLboolean, GLboolean, GLboolean, GLboolean);
    #endif
-    #if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_WEBGL)
+    #ifdef MAGNUM_TARGET_GLES
    void(APIENTRY *polygonModeImplementation)(GLenum, GLenum);
    #endif
    #ifndef MAGNUM_TARGET_WEBGL
--- a/src/Magnum/GL/Implementation/driverSpecific.cpp
+++ b/src/Magnum/GL/Implementation/driverSpecific.cpp
@ -732,6 +732,16 @@ void Context::setupDriverWorkarounds() {
    #if __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ < 20000
    _setRequiredVersion(WEBGL::multi_draw, None);
    #endif
+    /* EXT_clip_control, EXT_polygon_offset_clamp and WEBGL_polygon_mode
+       entrypoints are only available since Emscripten 3.1.66:
+       https://github.com/emscripten-core/emscripten/pull/20841
+       However, the extension is advertised even on older versions and we have
+       no way to link to those entrypoints there. */
+    #if __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ < 30166
+    _setRequiredVersion(EXT::clip_control, None);
+    _setRequiredVersion(EXT::polygon_offset_clamp, None);
+    _setRequiredVersion(WEBGL::polygon_mode, None);
+    #endif
    #ifndef MAGNUM_TARGET_GLES2
    /* WEBGL_multi_draw_instanced_base_vertex_base_instance only since
       Emscripten 2.0.5: https://github.com/emscripten-core/emscripten/pull/12282 */
--- a/src/Magnum/GL/Renderer.cpp
+++ b/src/Magnum/GL/Renderer.cpp
@ -33,6 +33,16 @@
 #include "Magnum/GL/Implementation/State.h"
 #include "Magnum/GL/Implementation/RendererState.h"

+/* The __EMSCRIPTEN_major__ etc macros used to be passed implicitly, version
+   3.1.4 moved them to a version header and version 3.1.23 dropped the
+   backwards compatibility. To work consistently on all versions, including the
+   header only if the version macros aren't present.
+   https://github.com/emscripten-core/emscripten/commit/f99af02045357d3d8b12e63793cef36dfde4530a
+   https://github.com/emscripten-core/emscripten/commit/f76ddc702e4956aeedb658c49790cc352f892e4c */
+#if defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(__EMSCRIPTEN_major__)
+#include <emscripten/version.h>
+#endif
+
 namespace Magnum { namespace GL {

 Range1D Renderer::lineWidthRange() {
@ -137,7 +147,6 @@ void Renderer::setProvokingVertex(const ProvokingVertex mode) {
 }
 #endif

-#ifndef MAGNUM_TARGET_WEBGL
 void Renderer::setPolygonMode(const PolygonMode mode) {
    #ifndef MAGNUM_TARGET_GLES
    glPolygonMode
@ -146,7 +155,6 @@ void Renderer::setPolygonMode(const PolygonMode mode) {
    #endif
        (GL_FRONT_AND_BACK, GLenum(mode));
 }
-#endif

 void Renderer::setPolygonOffset(const Float factor, const Float units) {
    glPolygonOffset(factor, units);
@ -331,15 +339,17 @@ void Renderer::depthRangefImplementationDefault(const Float near, const Float fa
 }
 #endif

-#ifndef MAGNUM_TARGET_WEBGL
 void Renderer::setClipControl(const ClipOrigin origin, const ClipDepth depth) {
    #ifndef MAGNUM_TARGET_GLES
    glClipControl(GLenum(origin), GLenum(depth));
-    #else
+    #elif !defined(MAGNUM_TARGET_WEBGL) || __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ >= 30166
    glClipControlEXT(GLenum(origin), GLenum(depth));
+    #else
+    static_cast<void>(origin);
+    static_cast<void>(depth);
+    CORRADE_INTERNAL_ASSERT_UNREACHABLE();
    #endif
 }
-#endif

 void Renderer::setColorMask(const GLboolean allowRed, const GLboolean allowGreen, const GLboolean allowBlue, const GLboolean allowAlpha) {
    glColorMask(allowRed, allowGreen, allowBlue, allowAlpha);
--- a/src/Magnum/GL/Renderer.h
+++ b/src/Magnum/GL/Renderer.h
@ -417,7 +417,6 @@ class MAGNUM_GL_EXPORT Renderer {
             */
            PolygonOffsetFill = GL_POLYGON_OFFSET_FILL,

-            #ifndef MAGNUM_TARGET_WEBGL
            /**
             * Offset lines. Note that this affects only filled polygons
             * rendered with @ref setPolygonMode() set to
@ -426,15 +425,20 @@ class MAGNUM_GL_EXPORT Renderer {
             *      @ref setPolygonOffset()
             * @requires_es_extension Extension @gl_extension{NV,polygon_offset}
             *      or @m_class{m-doc-external} [ANGLE_polygon_mode](https://chromium.googlesource.com/angle/angle/+/HEAD/extensions/ANGLE_polygon_mode.txt)
-             * @requires_gles Only @ref Feature::PolygonOffsetFill is available
-             *      in WebGL.
+             * @requires_webgl_extension Extension @webgl_extension{WEBGL,polygon_mode}.
+             *      Note that this extension is only implemented since
+             *      Emscripten 3.1.66 and thus it's not even advertised on
+             *      older versions.
             */
            #ifndef MAGNUM_TARGET_GLES
            PolygonOffsetLine = GL_POLYGON_OFFSET_LINE,
-            #else
+            #elif !defined(MAGNUM_TARGET_WEBGL)
            PolygonOffsetLine = GL_POLYGON_OFFSET_LINE_NV,
+            #else
+            PolygonOffsetLine = GL_POLYGON_OFFSET_LINE_WEBGL,
            #endif

+            #ifndef MAGNUM_TARGET_WEBGL
            /**
             * Offset points. Note that this affects only filled polygons
             * rendered with @ref setPolygonMode() set to
@ -442,8 +446,8 @@ class MAGNUM_GL_EXPORT Renderer {
             * @see @ref Feature::PolygonOffsetFill, @ref Feature::PolygonOffsetLine,
             *      @ref setPolygonOffset()
             * @requires_es_extension Extension @gl_extension{NV,polygon_offset}
-             * @requires_gles Only @ref Feature::PolygonOffsetFill is available
-             *      in WebGL.
+             * @requires_gles Only @ref Feature::PolygonOffsetFill and
+             *      @ref Feature::PolygonOffsetPoint is available in WebGL.
             */
            #ifndef MAGNUM_TARGET_GLES
            PolygonOffsetPoint = GL_POLYGON_OFFSET_POINT,
@ -856,7 +860,6 @@ class MAGNUM_GL_EXPORT Renderer {
        static void setProvokingVertex(ProvokingVertex mode);
        #endif

-        #ifndef MAGNUM_TARGET_WEBGL
        /**
         * @brief Polygon mode
         *
@ -866,7 +869,10 @@ class MAGNUM_GL_EXPORT Renderer {
         *      @m_class{m-doc-external} [ANGLE_polygon_mode](https://chromium.googlesource.com/angle/angle/+/HEAD/extensions/ANGLE_polygon_mode.txt).
         *      Otherwise behaves always like @ref PolygonMode::Fill. See
         *      @ref Mesh::setPrimitive() for a possible workaround.
-         * @requires_gles WebGL behaves always like @ref PolygonMode::Fill. See
+         * @requires_webgl_extension Extension @webgl_extension{WEBGL,polygon_mode}.
+         *      Note that this extension is only implemented since Emscripten
+         *      3.1.66 and thus it's not even advertised on older versions.
+         *      Otherwise behaves always like @ref PolygonMode::Fill. See
         *      @ref Mesh::setPrimitive() for a possible workaround.
         */
        enum class PolygonMode: GLenum {
@ -875,8 +881,10 @@ class MAGNUM_GL_EXPORT Renderer {
             */
            #ifndef MAGNUM_TARGET_GLES
            Fill = GL_FILL,
-            #else
+            #elif !defined(MAGNUM_TARGET_WEBGL)
            Fill = GL_FILL_NV,
+            #else
+            Fill = GL_FILL_WEBGL,
            #endif

            /**
@ -884,21 +892,26 @@ class MAGNUM_GL_EXPORT Renderer {
             */
            #ifndef MAGNUM_TARGET_GLES
            Line = GL_LINE,
-            #else
+            #elif !defined(MAGNUM_TARGET_WEBGL)
            Line = GL_LINE_NV,
+            #else
+            Line = GL_LINE_WEBGL,
            #endif

+            #ifndef MAGNUM_TARGET_WEBGL
            /**
             * Starts of boundary edges are drawn as points. See also
             * @ref setPointSize().
             * @requires_es_extension Extension @gl_extension{NV,polygon_mode},
             *      not available with @m_class{m-doc-external} [ANGLE_polygon_mode](https://chromium.googlesource.com/angle/angle/+/HEAD/extensions/ANGLE_polygon_mode.txt)
+             * @requires_gles Not available in @webgl_extension{WEBGL,polygon_mode}
             */
            #ifndef MAGNUM_TARGET_GLES
            Point = GL_POINT
            #else
            Point = GL_POINT_NV
            #endif
+            #endif
        };

        /**
@ -910,11 +923,13 @@ class MAGNUM_GL_EXPORT Renderer {
         *      @m_class{m-doc-external} [ANGLE_polygon_mode](https://chromium.googlesource.com/angle/angle/+/HEAD/extensions/ANGLE_polygon_mode.txt).
         *      Otherwise behaves always like the default. See
         *      @ref Mesh::setPrimitive() for possible workaround.
-         * @requires_gles WebGL behaves always like the default. See
+         * @requires_webgl_extension Extension @webgl_extension{WEBGL,polygon_mode}.
+         *      Note that this extension is only implemented since Emscripten
+         *      3.1.66 and thus it's not even advertised on older versions.
+         *      Otherwise behaves always like the default. See
         *      @ref Mesh::setPrimitive() for possible workaround.
         */
        static void setPolygonMode(PolygonMode mode);
-        #endif

        /**
         * @brief Set polygon offset
@ -1234,7 +1249,6 @@ class MAGNUM_GL_EXPORT Renderer {

        /** @{ @name Depth testing and clip control */

-        #ifndef MAGNUM_TARGET_WEBGL
        /**
         * @brief Clip origin
         * @m_since_latest
@ -1243,7 +1257,9 @@ class MAGNUM_GL_EXPORT Renderer {
         * @m_enum_values_as_keywords
         * @requires_gl45 Extension @gl_extension{ARB,clip_control}
         * @requires_es_extension Extension @gl_extension{EXT,clip_control}
-         * @requires_gles Clip control is not available in WebGL.
+         * @requires_webgl_extension Extension @webgl_extension{EXT,clip_control}.
+         *      Note that this extension is only implemented since Emscripten
+         *      3.1.66 and thus it's not even advertised on older versions.
         */
        enum class ClipOrigin: GLenum {
            /** Lower left */
@ -1269,7 +1285,9 @@ class MAGNUM_GL_EXPORT Renderer {
         * @m_enum_values_as_keywords
         * @requires_gl45 Extension @gl_extension{ARB,clip_control}
         * @requires_es_extension Extension @gl_extension{EXT,clip_control}
-         * @requires_gles Clip control is not available in WebGL.
+         * @requires_webgl_extension Extension @webgl_extension{EXT,clip_control}.
+         *      Note that this extension is only implemented since Emscripten
+         *      3.1.66 and thus it's not even advertised on older versions.
         */
        enum class ClipDepth: GLenum {
            /** -1 to 1 */
@ -1286,7 +1304,6 @@ class MAGNUM_GL_EXPORT Renderer {
            ZeroToOne = GL_ZERO_TO_ONE_EXT,
            #endif
        };
-        #endif

        /**
         * @brief Depth function
@ -1335,7 +1352,6 @@ class MAGNUM_GL_EXPORT Renderer {
         */
        static void setDepthRange(Float near, Float far);

-        #ifndef MAGNUM_TARGET_WEBGL
        /**
         * @brief Set clipping behavior
         * @m_since_latest
@ -1345,10 +1361,11 @@ class MAGNUM_GL_EXPORT Renderer {
         * @see @fn_gl_keyword{ClipControl}
         * @requires_gl45 Extension @gl_extension{ARB,clip_control}
         * @requires_es_extension Extension @gl_extension{EXT,clip_control}
-         * @requires_gles Clip control is not available in WebGL.
+         * @requires_webgl_extension Extension @webgl_extension{EXT,clip_control}.
+         *      Note that this extension is only implemented since Emscripten
+         *      3.1.66 and thus it's not even advertised on older versions.
         */
        static void setClipControl(ClipOrigin origin, ClipDepth depth);
-        #endif

        /* Since 1.8.17, the original short-hand group closing doesn't work
           anymore. FFS. */
--- a/src/Magnum/GL/Test/RendererGLTest.cpp
+++ b/src/Magnum/GL/Test/RendererGLTest.cpp
@ -61,9 +61,7 @@ struct RendererGLTest: OpenGLTester {

    void maxLineWidth();
    void pointCoord();
-    #ifndef MAGNUM_TARGET_WEBGL
    void polygonMode();
-    #endif
    #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
    void patchParameters();
    #endif
@ -72,9 +70,7 @@ struct RendererGLTest: OpenGLTester {
    void drawBuffersBlend();
    #endif
    template<class T> void clearDepthDepthRange();
-    #ifndef MAGNUM_TARGET_WEBGL
    void clipControl();
-    #endif

    private:
        PluginManager::Manager<Trade::AbstractImporter> _manager{"nonexistent"};
@ -89,9 +85,7 @@ using namespace Math::Literals;
 RendererGLTest::RendererGLTest() {
    addTests({&RendererGLTest::maxLineWidth,
              &RendererGLTest::pointCoord,
-              #ifndef MAGNUM_TARGET_WEBGL
              &RendererGLTest::polygonMode,
-              #endif
              #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
              &RendererGLTest::patchParameters,
              #endif
@ -103,10 +97,7 @@ RendererGLTest::RendererGLTest() {
              &RendererGLTest::clearDepthDepthRange<Double>,
              #endif
              &RendererGLTest::clearDepthDepthRange<Float>,
-              #ifndef MAGNUM_TARGET_WEBGL
-              &RendererGLTest::clipControl
-              #endif
-              });
+              &RendererGLTest::clipControl});

    /* Load the plugins directly from the build tree. Otherwise they're either
       static and already loaded or not present in the build tree */
@ -259,9 +250,11 @@ void RendererGLTest::pointCoord() {
        (DebugTools::CompareImageToFile{_manager, maxThreshold, meanThreshold}));
 }

-#ifndef MAGNUM_TARGET_WEBGL
 void RendererGLTest::polygonMode() {
-    #ifdef MAGNUM_TARGET_GLES
+    #ifdef MAGNUM_TARGET_WEBGL
+    if(!Context::current().isExtensionSupported<Extensions::WEBGL::polygon_mode>())
+        CORRADE_SKIP(Extensions::WEBGL::polygon_mode::string() << "is not supported.");
+    #elif defined(MAGNUM_TARGET_GLES)
    if(!Context::current().isExtensionSupported<Extensions::NV::polygon_mode>() &&
       !Context::current().isExtensionSupported<Extensions::ANGLE::polygon_mode>())
        CORRADE_SKIP("Neither" << Extensions::NV::polygon_mode::string() << "nor" << Extensions::ANGLE::polygon_mode::string() << "is supported.");
@ -273,7 +266,6 @@ void RendererGLTest::polygonMode() {
    Renderer::setPolygonMode(Renderer::PolygonMode::Fill);
    MAGNUM_VERIFY_NO_GL_ERROR();
 }
-#endif

 #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
 void RendererGLTest::patchParameters() {
@ -343,7 +335,6 @@ template<class T> void RendererGLTest::clearDepthDepthRange() {
    MAGNUM_VERIFY_NO_GL_ERROR();
 }

-#ifndef MAGNUM_TARGET_WEBGL
 void RendererGLTest::clipControl() {
    #ifndef MAGNUM_TARGET_GLES
    if(!Context::current().isExtensionSupported<Extensions::ARB::clip_control>())
@ -359,7 +350,6 @@ void RendererGLTest::clipControl() {

    MAGNUM_VERIFY_NO_GL_ERROR();
 }
-#endif

 }}}}