DebugTools: make bufferData()/bufferSubData() available on WebGL 2.0

Co-authored-by: Vladimír Vondruš <mosra@centrum.cz>

src/Magnum/DebugTools/BufferData.cpp

@@ -29,13 +29,14 @@
 
 #include "Magnum/GL/Buffer.h"
 
-#if defined(MAGNUM_TARGET_GLES) || defined(MAGNUM_BUILD_DEPRECATED)
+#if !defined(MAGNUM_TARGET_WEBGL) && (defined(MAGNUM_TARGET_GLES) || defined(MAGNUM_BUILD_DEPRECATED))
 #include <Corrade/Utility/Algorithms.h>
 #endif
 
+#if !(defined(MAGNUM_TARGET_WEBGL) && (defined(MAGNUM_TARGET_GLES2) || __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ < 20017))
 namespace Magnum { namespace DebugTools {
 
-#ifdef MAGNUM_BUILD_DEPRECATED
+#if defined(MAGNUM_BUILD_DEPRECATED) && !defined(MAGNUM_TARGET_WEBGL)
 namespace Implementation {
 
 /* Used only by deprecated bufferSubData<T>() */
@@ -49,7 +50,7 @@ void bufferSubData(GL::Buffer& buffer, GLintptr offset, GLsizeiptr size, void* o
 #endif
 
 Containers::Array<char> bufferSubData(GL::Buffer& buffer, GLintptr offset, GLsizeiptr size) {
-    #ifndef MAGNUM_TARGET_GLES
+    #if !defined(MAGNUM_TARGET_GLES) || defined(MAGNUM_TARGET_WEBGL)
     return buffer.subData(offset, size);
     #else
     Containers::Array<char> data{NoInit, std::size_t(size)};
@@ -66,3 +67,4 @@ Containers::Array<char> bufferData(GL::Buffer& buffer) {
 }
 
 }}
+#endif

src/Magnum/DebugTools/BufferData.h

@@ -25,7 +25,7 @@
     DEALINGS IN THE SOFTWARE.
 */
 
-#if defined(MAGNUM_TARGET_GL) && !defined(MAGNUM_TARGET_WEBGL)
+#if defined(MAGNUM_TARGET_GL) && !(defined(MAGNUM_TARGET_WEBGL) && defined(MAGNUM_TARGET_GLES2))
 /** @file
  * @brief Function @ref Magnum::DebugTools::bufferData(), @ref Magnum::DebugTools::bufferSubData()
  */
@@ -45,7 +45,7 @@
 #include "Magnum/GL/Buffer.h"
 #endif
 
-#if defined(MAGNUM_TARGET_GL) && !defined(MAGNUM_TARGET_WEBGL)
+#if defined(MAGNUM_TARGET_GL) && !(defined(MAGNUM_TARGET_WEBGL) && (defined(MAGNUM_TARGET_GLES2) || __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ < 20017))
 namespace Magnum { namespace DebugTools {
 
 #ifdef MAGNUM_BUILD_DEPRECATED
@@ -60,8 +60,8 @@ namespace Implementation {
 @brief Buffer subdata
 
 Emulates @ref GL::Buffer::subData() call on platforms that don't support it
-(such as OpenGL ES) by using @ref GL::Buffer::mapRead(). On desktop GL it's
-just an alias to @ref GL::Buffer::subData().
+(such as OpenGL ES) by using @ref GL::Buffer::mapRead(). On desktop GL and
+WebGL 2.0 it's just an alias to @ref GL::Buffer::subData().
 
 @note This function is available only if Magnum is compiled with
     @ref MAGNUM_TARGET_GL "TARGET_GL" enabled (done by default). See
@@ -69,11 +69,12 @@ just an alias to @ref GL::Buffer::subData().
 
 @requires_gles30 Extension @gl_extension{EXT,map_buffer_range} in OpenGL ES
     2.0.
-@requires_gles Buffer mapping is not available in WebGL.
+@requires_webgl20 Buffer data queries or buffer mapping are not available in
+    WebGL 1.0. Emscripten 2.0.17 or higher is required in WebGL2.
 */
 MAGNUM_DEBUGTOOLS_EXPORT Containers::Array<char> bufferSubData(GL::Buffer& buffer, GLintptr offset, GLsizeiptr size);
 
-#ifdef MAGNUM_BUILD_DEPRECATED
+#if defined(MAGNUM_BUILD_DEPRECATED) && !defined(MAGNUM_TARGET_WEBGL)
 /**
 @copybrief bufferSubData()
 @m_deprecated_since_latest Use non-templated @ref bufferSubData() and
@@ -97,8 +98,8 @@ template<class T> CORRADE_DEPRECATED("use non-templated bufferSubData() and Cont
 @brief Buffer data
 
 Emulates @ref GL::Buffer::data() call on platforms that don't support it (such
-as OpenGL ES) by using @ref GL::Buffer::mapRead(). On desktop GL it's just an
-alias to @ref GL::Buffer::data().
+as OpenGL ES) by using @ref GL::Buffer::mapRead(). On desktop GL and WebGL 2.0
+it's just an alias to @ref GL::Buffer::data().
 
 @note This function is available only if Magnum is compiled with
     @ref MAGNUM_TARGET_GL "TARGET_GL" enabled (done by default). See
@@ -106,11 +107,12 @@ alias to @ref GL::Buffer::data().
 
 @requires_gles30 Extension @gl_extension{EXT,map_buffer_range} in OpenGL ES
     2.0.
-@requires_gles Buffer mapping is not available in WebGL.
+@requires_webgl20 Buffer data queries or buffer mapping are not available in
+    WebGL 1.0. Emscripten 2.0.17 or higher is required in WebGL2.
 */
 MAGNUM_DEBUGTOOLS_EXPORT Containers::Array<char> bufferData(GL::Buffer& buffer);
 
-#ifdef MAGNUM_BUILD_DEPRECATED
+#if defined(MAGNUM_BUILD_DEPRECATED) && !defined(MAGNUM_TARGET_WEBGL)
 /**
 @copybrief bufferData()
 @m_deprecated_since_latest Use non-templated @ref bufferData() and
@@ -134,7 +136,7 @@ template<class T = char> CORRADE_DEPRECATED("use non-templated bufferData() and
 
 }}
 #else
-#error this header is available only in the OpenGL (ES) build and not available in the WebGL build
+#error this header is not available in a WebGL 1.0 build or on Emscripten < 2.0.17
 #endif
 
 #endif

src/Magnum/DebugTools/CMakeLists.txt

@@ -72,7 +72,7 @@ if(TARGET_GL)
         endif()
     endif()
 
-    if(NOT MAGNUM_TARGET_WEBGL)
+    if(NOT (MAGNUM_TARGET_WEBGL AND MAGNUM_TARGET_GLES2))
         list(APPEND MagnumDebugTools_SRCS
             BufferData.cpp)
 

src/Magnum/DebugTools/Test/BufferDataGLTest.cpp

@@ -37,6 +37,10 @@ namespace Magnum { namespace DebugTools { namespace Test { namespace {
 struct BufferDataGLTest: GL::OpenGLTester {
     explicit BufferDataGLTest();
 
+    /* To avoid complex ifdefing on Esmcripten, assumes that tests are built
+       on 2.0.17+. On older versions the linker will fail due to missing
+       glGetBufferSubData(). */
+
     void data();
     void subData();
 };

src/Magnum/DebugTools/Test/CMakeLists.txt

@@ -118,7 +118,7 @@ if(TARGET_GL)
         corrade_add_test(DebugToolsTextureImageGLTest TextureImageGLTest.cpp
             LIBRARIES MagnumDebugTools MagnumOpenGLTester)
 
-        if(NOT MAGNUM_TARGET_WEBGL)
+        if(NOT (MAGNUM_TARGET_WEBGL AND MAGNUM_TARGET_GLES2))
             corrade_add_test(DebugToolsBufferDataGLTest BufferDataGLTest.cpp
                 LIBRARIES MagnumDebugTools MagnumOpenGLTester)
         endif()

src/Magnum/DebugTools/Test/TextureImageGLTest.cpp

@@ -38,7 +38,7 @@
 #include "Magnum/GL/TextureFormat.h"
 #include "Magnum/Math/Range.h"
 
-#if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+#ifndef MAGNUM_TARGET_GLES2
 #include "Magnum/DebugTools/BufferData.h"
 #include "Magnum/GL/BufferImage.h"
 #endif
@@ -48,14 +48,18 @@ namespace Magnum { namespace DebugTools { namespace Test { namespace {
 struct TextureImageGLTest: GL::OpenGLTester {
     explicit TextureImageGLTest();
 
+    /* To avoid complex ifdefing on Esmcripten, assumes that tests are built
+       on 2.0.17+. On older versions the linker will fail due to missing
+       glGetBufferSubData(). */
+
     void subImage2D();
-    #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+    #ifndef MAGNUM_TARGET_GLES2
     void subImage2DBuffer();
     #endif
     void subImage2DGeneric();
 
     void subImageCube();
-    #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+    #ifndef MAGNUM_TARGET_GLES2
     void subImageCubeBuffer();
     #endif
 
@@ -68,13 +72,13 @@ struct TextureImageGLTest: GL::OpenGLTester {
 
 TextureImageGLTest::TextureImageGLTest() {
     addTests({&TextureImageGLTest::subImage2D,
-              #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+              #ifndef MAGNUM_TARGET_GLES2
               &TextureImageGLTest::subImage2DBuffer,
               #endif
               &TextureImageGLTest::subImage2DGeneric,
 
               &TextureImageGLTest::subImageCube,
-              #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+              #ifndef MAGNUM_TARGET_GLES2
               &TextureImageGLTest::subImageCubeBuffer,
               #endif
 
@@ -111,7 +115,7 @@ void TextureImageGLTest::subImage2D() {
         Containers::arrayView(Data2D), TestSuite::Compare::Container);
 }
 
-#if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+#ifndef MAGNUM_TARGET_GLES2
 void TextureImageGLTest::subImage2DBuffer() {
     GL::Texture2D texture;
     texture.setImage(0, GL::TextureFormat::RGBA8, ImageView2D{GL::PixelFormat::RGBA, GL::PixelType::UnsignedByte, Vector2i{2}, Data2D});
@@ -177,7 +181,7 @@ void TextureImageGLTest::subImageCube() {
         Containers::arrayView(Data2D), TestSuite::Compare::Container);
 }
 
-#if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
+#ifndef MAGNUM_TARGET_GLES2
 void TextureImageGLTest::subImageCubeBuffer() {
     ImageView2D view{GL::PixelFormat::RGBA, GL::PixelType::UnsignedByte, Vector2i{2}, Data2D};