Fix T39420: Cycles viewport/preview flickers, when moving mouse across editors

Issue was caused by the wrong usage of OCIO GLSL binding API. To make it
work properly on pre-GLSL-1.3 drivers shader is to be enabled after the
texture is binded to the opengl context. Otherwise it wouldn't know the
proper texture size.

This is actually a regression in 2.70 and to be ported to 'a'.

intern/cycles/blender/blender_session.cpp

@@ -592,16 +592,14 @@ bool BlenderSession::draw(int w, int h)
 
 	/* draw */
 	BufferParams buffer_params = BlenderSync::get_buffer_params(b_render, b_scene, b_v3d, b_rv3d, scene->camera, width, height);
+	DeviceDrawParams draw_params;
 
-	if(session->params.display_buffer_linear)
+	if(session->params.display_buffer_linear) {
-		b_engine.bind_display_space_shader(b_scene);
+		draw_params.bind_display_space_shader_cb = function_bind(&BL::RenderEngine::bind_display_space_shader, &b_engine, b_scene);
+		draw_params.unbind_display_space_shader_cb = function_bind(&BL::RenderEngine::unbind_display_space_shader, &b_engine);
+	}
 
-	bool draw_ok = !session->draw(buffer_params);
+	return !session->draw(buffer_params, draw_params);
-
-	if(session->params.display_buffer_linear)
-		b_engine.unbind_display_space_shader();
-	
-	return draw_ok;
 }
 
 void BlenderSession::get_status(string& status, string& substatus)

intern/cycles/device/device.cpp

@@ -53,7 +53,8 @@ void Device::pixels_free(device_memory& mem)
 	mem_free(mem);
 }
 
-void Device::draw_pixels(device_memory& rgba, int y, int w, int h, int dy, int width, int height, bool transparent)
+void Device::draw_pixels(device_memory& rgba, int y, int w, int h, int dy, int width, int height, bool transparent,
+	const DeviceDrawParams &draw_params)
 {
 	pixels_copy_from(rgba, y, w, h);
 
@@ -80,6 +81,10 @@ void Device::draw_pixels(device_memory& rgba, int y, int w, int h, int dy, int w
 
 		glEnable(GL_TEXTURE_2D);
 
+		if(draw_params.bind_display_space_shader_cb) {
+			draw_params.bind_display_space_shader_cb();
+		}
+
 		glPushMatrix();
 		glTranslatef(0.0f, (float)dy, 0.0f);
 
@@ -98,6 +103,10 @@ void Device::draw_pixels(device_memory& rgba, int y, int w, int h, int dy, int w
 
 		glPopMatrix();
 
+		if(draw_params.unbind_display_space_shader_cb) {
+			draw_params.unbind_display_space_shader_cb();
+		}
+
 		glBindTexture(GL_TEXTURE_2D, 0);
 		glDisable(GL_TEXTURE_2D);
 		glDeleteTextures(1, &texid);

intern/cycles/device/device.h

@@ -69,6 +69,11 @@ public:
 
 /* Device */
 
+struct DeviceDrawParams {
+	boost::function<void(void)> bind_display_space_shader_cb;
+	boost::function<void(void)> unbind_display_space_shader_cb;
+};
+
 class Device {
 protected:
 	Device(DeviceInfo& info_, Stats &stats_, bool background) : background(background), info(info_), stats(stats_) {}
@@ -121,7 +126,8 @@ public:
 	
 	/* opengl drawing */
 	virtual void draw_pixels(device_memory& mem, int y, int w, int h,
-		int dy, int width, int height, bool transparent);
+		int dy, int width, int height, bool transparent,
+		const DeviceDrawParams &draw_params);
 
 #ifdef WITH_NETWORK
 	/* networking */

intern/cycles/device/device_cuda.cpp

@@ -908,7 +908,8 @@ public:
 		}
 	}
 
-	void draw_pixels(device_memory& mem, int y, int w, int h, int dy, int width, int height, bool transparent)
+	void draw_pixels(device_memory& mem, int y, int w, int h, int dy, int width, int height, bool transparent,
+		const DeviceDrawParams &draw_params)
 	{
 		if(!background) {
 			PixelMem pmem = pixel_mem_map[mem.device_pointer];
@@ -941,6 +942,10 @@ public:
 
 			glColor3f(1.0f, 1.0f, 1.0f);
 
+			if(draw_params.bind_display_space_shader_cb) {
+				draw_params.bind_display_space_shader_cb();
+			}
+
 			glPushMatrix();
 			glTranslatef(0.0f, (float)dy, 0.0f);
 				
@@ -959,6 +964,10 @@ public:
 
 			glPopMatrix();
 
+			if(draw_params.unbind_display_space_shader_cb) {
+				draw_params.unbind_display_space_shader_cb();
+			}
+
 			if(transparent)
 				glDisable(GL_BLEND);
 			
@@ -970,7 +979,7 @@ public:
 			return;
 		}
 
-		Device::draw_pixels(mem, y, w, h, dy, width, height, transparent);
+		Device::draw_pixels(mem, y, w, h, dy, width, height, transparent, draw_params);
 	}
 
 	void thread_run(DeviceTask *task)

intern/cycles/device/device_multi.cpp

@@ -233,7 +233,8 @@ public:
 		mem.device_pointer = tmp;
 	}
 
-	void draw_pixels(device_memory& rgba, int y, int w, int h, int dy, int width, int height, bool transparent)
+	void draw_pixels(device_memory& rgba, int y, int w, int h, int dy, int width, int height, bool transparent,
+		const DeviceDrawParams &draw_params)
 	{
 		device_ptr tmp = rgba.device_pointer;
 		int i = 0, sub_h = h/devices.size();
@@ -247,7 +248,7 @@ public:
 			/* adjust math for w/width */
 
 			rgba.device_pointer = sub.ptr_map[tmp];
-			sub.device->draw_pixels(rgba, sy, w, sh, sdy, width, sheight, transparent);
+			sub.device->draw_pixels(rgba, sy, w, sh, sdy, width, sheight, transparent, draw_params);
 			i++;
 		}
 

intern/cycles/render/buffers.cpp

@@ -358,14 +358,14 @@ void DisplayBuffer::draw_set(int width, int height)
 	draw_height = height;
 }
 
-void DisplayBuffer::draw(Device *device)
+void DisplayBuffer::draw(Device *device, const DeviceDrawParams& draw_params)
 {
 	if(draw_width != 0 && draw_height != 0) {
 		glPushMatrix();
 		glTranslatef(params.full_x, params.full_y, 0.0f);
 		device_memory& rgba = rgba_data();
 
-		device->draw_pixels(rgba, 0, draw_width, draw_height, 0, params.width, params.height, transparent);
+		device->draw_pixels(rgba, 0, draw_width, draw_height, 0, params.width, params.height, transparent, draw_params);
 
 		glPopMatrix();
 	}

intern/cycles/render/buffers.h

@@ -31,6 +31,7 @@
 CCL_NAMESPACE_BEGIN
 
 class Device;
+class DeviceDrawParams;
 struct float4;
 
 /* Buffer Parameters
@@ -114,7 +115,7 @@ public:
 	void write(Device *device, const string& filename);
 
 	void draw_set(int width, int height);
-	void draw(Device *device);
+	void draw(Device *device, const DeviceDrawParams& draw_params);
 	bool draw_ready();
 
 	device_memory& rgba_data();

intern/cycles/render/session.cpp

@@ -151,7 +151,7 @@ void Session::reset_gpu(BufferParams& buffer_params, int samples)
 	pause_cond.notify_all();
 }
 
-bool Session::draw_gpu(BufferParams& buffer_params)
+bool Session::draw_gpu(BufferParams& buffer_params, DeviceDrawParams& draw_params)
 {
 	/* block for buffer access */
 	thread_scoped_lock display_lock(display_mutex);
@@ -170,7 +170,7 @@ bool Session::draw_gpu(BufferParams& buffer_params)
 				gpu_need_tonemap_cond.notify_all();
 			}
 
-			display->draw(device);
+			display->draw(device, draw_params);
 
 			if(display_outdated && (time_dt() - reset_time) > params.text_timeout)
 				return false;
@@ -315,7 +315,7 @@ void Session::reset_cpu(BufferParams& buffer_params, int samples)
 	pause_cond.notify_all();
 }
 
-bool Session::draw_cpu(BufferParams& buffer_params)
+bool Session::draw_cpu(BufferParams& buffer_params, DeviceDrawParams& draw_params)
 {
 	thread_scoped_lock display_lock(display_mutex);
 
@@ -324,7 +324,7 @@ bool Session::draw_cpu(BufferParams& buffer_params)
 		/* then verify the buffers have the expected size, so we don't
 		 * draw previous results in a resized window */
 		if(!buffer_params.modified(display->params)) {
-			display->draw(device);
+			display->draw(device, draw_params);
 
 			if(display_outdated && (time_dt() - reset_time) > params.text_timeout)
 				return false;
@@ -624,12 +624,12 @@ void Session::run()
 		progress.set_update();
 }
 
-bool Session::draw(BufferParams& buffer_params)
+bool Session::draw(BufferParams& buffer_params, DeviceDrawParams &draw_params)
 {
 	if(device_use_gl)
-		return draw_gpu(buffer_params);
+		return draw_gpu(buffer_params, draw_params);
 	else
-		return draw_cpu(buffer_params);
+		return draw_cpu(buffer_params, draw_params);
 }
 
 void Session::reset_(BufferParams& buffer_params, int samples)

intern/cycles/render/session.h

@@ -128,7 +128,7 @@ public:
 	~Session();
 
 	void start();
-	bool draw(BufferParams& params);
+	bool draw(BufferParams& params, DeviceDrawParams& draw_params);
 	void wait();
 
 	bool ready_to_reset();
@@ -155,11 +155,11 @@ protected:
 	void reset_(BufferParams& params, int samples);
 
 	void run_cpu();
-	bool draw_cpu(BufferParams& params);
+	bool draw_cpu(BufferParams& params, DeviceDrawParams& draw_params);
 	void reset_cpu(BufferParams& params, int samples);
 
 	void run_gpu();
-	bool draw_gpu(BufferParams& params);
+	bool draw_gpu(BufferParams& params, DeviceDrawParams& draw_params);
 	void reset_gpu(BufferParams& params, int samples);
 
 	bool acquire_tile(Device *tile_device, RenderTile& tile);