Fixed Canvases on iOS, added support for Canvas MSAA on OpenGL ES 3.

--HG--
branch : minor

src/modules/graphics/opengl/Canvas.cpp

@@ -520,7 +520,7 @@ bool Canvas::createMSAAFBO(GLenum internalformat)
 	// Create our FBO without a texture.
 	status = strategy->createFBO(fbo, 0);
 
-	GLuint previous = 0;
+	GLuint previous = gl.getDefaultFBO();
 	if (current != this)
 	{
 		if (current != nullptr)
@@ -567,11 +567,8 @@ bool Canvas::loadVolatile()
 		return false;
 	}
 
-	int max_samples = 0;
-	if (GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_object || GLAD_EXT_framebuffer_multisample)
-		glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
-
-	requested_samples = std::max(std::min(requested_samples, max_samples), 0);
+	requested_samples = std::min(requested_samples, gl.getMaxRenderbufferSamples());
+	requested_samples = std::max(requested_samples, 0);
 
 	glGenTextures(1, &texture);
 	gl.bindTexture(texture);
@@ -596,14 +593,8 @@ bool Canvas::loadVolatile()
 	while (glGetError() != GL_NO_ERROR)
 		/* Clear the error buffer. */;
 
-	glTexImage2D(GL_TEXTURE_2D,
-	             0,
-	             iformat,
-	             width, height,
-	             0,
-	             externalformat,
-	             textype,
-	             nullptr);
+	glTexImage2D(GL_TEXTURE_2D, 0, iformat, width, height, 0,
+	             externalformat, textype, nullptr);
 
 	if (glGetError() != GL_NO_ERROR)
 	{
@@ -890,7 +881,7 @@ void Canvas::clear(Color c)
 	if (strategy == &strategyNone)
 		return;
 
-	GLuint previous = 0;
+	GLuint previous = gl.getDefaultFBO();
 
 	if (current != this)
 	{
@@ -1024,12 +1015,12 @@ bool Canvas::resolveMSAA()
 	if (!msaa_dirty)
 		return true;
 
-	GLuint previous = 0;
+	GLuint previous = gl.getDefaultFBO();
 	if (current != nullptr)
 		previous = current->fbo;
 
 	// Do the MSAA resolve by blitting the MSAA renderbuffer to the texture.
-	if (GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_object)
+	if (GLAD_ES_VERSION_3_0 || GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_object)
 	{
 		glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
 		glBindFramebuffer(GL_DRAW_FRAMEBUFFER, resolve_fbo);

src/modules/graphics/opengl/Graphics.cpp

@@ -38,6 +38,10 @@
 #include <cmath>
 #include <cstdio>
 
+#ifdef LOVE_IOS
+#include <SDL_system.h>
+#endif
+
 namespace love
 {
 namespace graphics
@@ -454,6 +458,12 @@ void Graphics::present()
 			glDiscardFramebufferEXT(GL_FRAMEBUFFER, 2, attachments);
 	}
 
+#ifdef LOVE_IOS
+	// Hack: SDL's color renderbuffer needs to be bound when swapBuffers is called.
+	GLuint rbo = SDL_iPhoneGetViewRenderbuffer(SDL_GL_GetCurrentWindow());
+	glBindRenderbuffer(GL_RENDERBUFFER, rbo);
+#endif
+
 	currentWindow->swapBuffers();
 
 	// Restore the currently active canvas, if there is one.
@@ -1286,13 +1296,7 @@ double Graphics::getSystemLimit(SystemLimit limittype) const
 		limit = (double) gl.getMaxRenderTargets();
 		break;
 	case Graphics::LIMIT_CANVAS_MSAA:
-		if (GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_object
-			|| GLAD_EXT_framebuffer_multisample)
-		{
-			GLint intlimit = 0;
-			glGetIntegerv(GL_MAX_SAMPLES, &intlimit);
-			limit = (double) intlimit;
-		}
+		limit = (double) gl.getMaxRenderbufferSamples();
 		break;
 	default:
 		break;

src/modules/graphics/opengl/OpenGL.cpp

@@ -36,6 +36,10 @@
 // For SDL_GL_GetProcAddress.
 #include <SDL_video.h>
 
+#ifdef LOVE_IOS
+#include <SDL_system.h>
+#endif
+
 namespace love
 {
 namespace graphics
@@ -49,6 +53,7 @@ OpenGL::OpenGL()
 	, maxAnisotropy(1.0f)
 	, maxTextureSize(0)
 	, maxRenderTargets(0)
+	, maxRenderbufferSamples(0)
 	, vendor(VENDOR_UNKNOWN)
 	, state()
 {
@@ -124,8 +129,6 @@ void OpenGL::setupContext()
 
 	glActiveTexture(curgltextureunit);
 
-	glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, (GLint *) &state.defaultFBO);
-
 	BlendState blend = {GL_ONE, GL_ONE, GL_ZERO, GL_ZERO, GL_FUNC_ADD};
 	setBlendState(blend);
 
@@ -215,6 +218,11 @@ void OpenGL::initMaxValues()
 	}
 
 	maxRenderTargets = std::min(maxattachments, maxdrawbuffers);
+
+	if (GLAD_ES_VERSION_3_0 || GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_object || GLAD_EXT_framebuffer_multisample)
+		glGetIntegerv(GL_MAX_SAMPLES, &maxRenderbufferSamples);
+	else
+		maxRenderbufferSamples = 0;
 }
 
 void OpenGL::initMatrices()
@@ -423,7 +431,12 @@ float OpenGL::getPointSize() const
 
 GLuint OpenGL::getDefaultFBO() const
 {
-	return state.defaultFBO;
+#ifdef LOVE_IOS
+	// Hack: iOS uses a custom FBO.
+	return SDL_iPhoneGetViewFramebuffer(SDL_GL_GetCurrentWindow());
+#else
+	return 0;
+#endif
 }
 
 GLuint OpenGL::getDefaultTexture() const
@@ -560,6 +573,11 @@ int OpenGL::getMaxRenderTargets() const
 	return maxRenderTargets;
 }
 
+int OpenGL::getMaxRenderbufferSamples() const
+{
+	return maxRenderbufferSamples;
+}
+
 void OpenGL::updateTextureMemorySize(size_t oldsize, size_t newsize)
 {
 	int64 memsize = (int64) stats.textureMemory + ((int64 )newsize -  (int64) oldsize);

src/modules/graphics/opengl/OpenGL.h

@@ -310,6 +310,11 @@ public:
 	 **/
 	int getMaxRenderTargets() const;
 
+	/**
+	 * Returns the maximum supported number of MSAA samples for renderbuffers.
+	 **/
+	int getMaxRenderbufferSamples() const;
+
 	void updateTextureMemorySize(size_t oldsize, size_t newsize);
 
 	/**
@@ -335,6 +340,7 @@ private:
 	float maxAnisotropy;
 	int maxTextureSize;
 	int maxRenderTargets;
+	int maxRenderbufferSamples;
 
 	Vendor vendor;
 
@@ -357,7 +363,6 @@ private:
 
 		float pointSize;
 
-		GLuint defaultFBO;
 		GLuint defaultTexture;
 
 		BlendState blend;