vbo instancing for emscripten (#7808)

Author: NickHardeman

libs/openFrameworks/gl/ofGLProgrammableRenderer.cpp

@@ -230,8 +230,10 @@ void ofGLProgrammableRenderer::draw(const ofVboMesh & mesh, ofPolyRenderMode ren
 void ofGLProgrammableRenderer::drawInstanced(const ofVboMesh & mesh, ofPolyRenderMode renderType, int primCount) const {
 	if (mesh.getNumVertices() == 0) return;
 	GLuint mode = ofGetGLPrimitiveMode(mesh.getMode());
-#ifndef TARGET_OPENGLES
+#if !defined( TARGET_OPENGLES ) || defined(TARGET_EMSCRIPTEN)
+	#if !defined(TARGET_EMSCRIPTEN)
 	glPolygonMode(GL_FRONT_AND_BACK, ofGetGLPolyMode(renderType));
+	#endif
 	if (mesh.getNumIndices() && renderType != OF_MESH_POINTS) {
 		if (primCount <= 1) {
 			drawElements(mesh.getVbo(), mode, mesh.getNumIndices());
@@ -251,8 +253,9 @@ void ofGLProgrammableRenderer::drawInstanced(const ofVboMesh & mesh, ofPolyRende
 	// after we're finished drawing, following the principle of least surprise.
 	// ideally the glPolygonMode (or the polygon draw mode) should be part of ofStyle so that we can keep track
 	// of its state on the client side...
-
+	#if !defined(TARGET_EMSCRIPTEN)
 	glPolygonMode(GL_FRONT_AND_BACK, currentStyle.bFill ? GL_FILL : GL_LINE);
+	#endif
 #else
 	if (renderType == OF_MESH_POINTS) {
 		draw(mesh.getVbo(), GL_POINTS, 0, mesh.getNumVertices());
@@ -464,14 +467,18 @@ void ofGLProgrammableRenderer::drawElementsInstanced(const ofVbo & vbo, GLuint d
 	if (vbo.getUsingVerts()) {
 		vbo.bind();
 		const_cast<ofGLProgrammableRenderer *>(this)->setAttributes(vbo.getUsingVerts(), vbo.getUsingColors(), vbo.getUsingTexCoords(), vbo.getUsingNormals());
-#ifdef TARGET_OPENGLES
+#if defined(TARGET_OPENGLES) && !defined(TARGET_EMSCRIPTEN) // TODO: Check against OPENGL_ES Version
 		// todo: activate instancing once OPENGL ES supports instancing, starting with version 3.0
 		// unfortunately there is currently no easy way within oF to query the current OpenGL version.
 		// https://www.khronos.org/opengles/sdk/docs/man3/xhtml/glDrawElementsInstanced.xml
 		ofLogWarning("ofVbo") << "drawElementsInstanced(): hardware instancing is not supported on OpenGL ES < 3.0";
 		// glDrawElementsInstanced(drawMode, amt, GL_UNSIGNED_SHORT, nullptr, primCount);
 #else
+		#if defined(TARGET_OPENGLES)
+		glDrawElementsInstanced(drawMode, amt, GL_UNSIGNED_SHORT, nullptr, primCount);
+		#else
 		glDrawElementsInstanced(drawMode, amt, GL_UNSIGNED_INT, nullptr, primCount);
+		#endif
 #endif
 		vbo.unbind();
 	}