fix OpenGL Render to image (T51082)

This restores the feature for legacy viewport only. Modern viewport, Clay, Eevee, etc. will need further work.

Eventually we should rename this something other than "OpenGL".

1 files changed, 31 insertions, 20 deletions

diff --git a/source/blender/editors/space_view3d/view3d_draw_legacy.c b/source/blender/editors/space_view3d/view3d_draw_legacy.c
index 27e4dec9d23..3d43bc011e6 100644
--- a/source/blender/editors/space_view3d/view3d_draw_legacy.c
+++ b/source/blender/editors/space_view3d/view3d_draw_legacy.c
@@ -1777,18 +1777,11 @@ static void view3d_main_region_clear(Scene *scene, View3D *v3d, ARegion *ar)
 {
 	glClear(GL_DEPTH_BUFFER_BIT);
 
-	glMatrixMode(GL_PROJECTION);
-	gpuLoadIdentity();
-	glMatrixMode(GL_MODELVIEW);
-	gpuLoadIdentity();
-
 	if (scene->world && (v3d->flag3 & V3D_SHOW_WORLD)) {
 		VP_view3d_draw_background_world(scene, v3d, ar->regiondata);
 	}
 	else {
 		VP_view3d_draw_background_none();
-
-	glEnable(GL_DEPTH_TEST);
 	}
 }
 
@@ -1805,8 +1798,6 @@ void ED_view3d_draw_offscreen(
 	bool do_compositing = false;
 	RegionView3D *rv3d = ar->regiondata;
 
-	gpuPushMatrix();
-
 	/* set temporary new size */
 	int bwinx = ar->winx;
 	int bwiny = ar->winy;
@@ -1832,7 +1823,22 @@ void ED_view3d_draw_offscreen(
 		GPU_free_images_anim();
 	}
 
-	/* setup view matrices before fx or unbinding the offscreen buffers will cause issues */
+	glMatrixMode(GL_PROJECTION);
+	gpuPushMatrix();
+	gpuLoadIdentity();
+	glMatrixMode(GL_MODELVIEW);
+	gpuPushMatrix();
+	gpuLoadIdentity();
+
+	/* clear opengl buffers */
+	if (do_sky) {
+		view3d_main_region_clear(scene, v3d, ar);
+	}
+	else {
+		glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	}
+
 	if ((viewname != NULL && viewname[0] != '\0') && (viewmat == NULL) && rv3d->persp == RV3D_CAMOB && v3d->camera)
 		view3d_stereo3d_setup_offscreen(scene, v3d, ar, winmat, viewname);
 	else
@@ -1853,15 +1859,6 @@ void ED_view3d_draw_offscreen(
 			v3d->fx_settings.ssao = ssao;
 	}
 
-	/* clear opengl buffers */
-	if (do_sky) {
-		view3d_main_region_clear(scene, v3d, ar);
-	}
-	else {
-		glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
-		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-	}
-
 	/* main drawing call */
 	view3d_draw_objects(NULL, scene, v3d, ar, NULL, do_bgpic, true, do_compositing ? fx : NULL);
 
@@ -1876,7 +1873,6 @@ void ED_view3d_draw_offscreen(
 		/* draw grease-pencil stuff */
 		ED_region_pixelspace(ar);
 
-
 		if (v3d->flag2 & V3D_SHOW_GPENCIL) {
 			/* draw grease-pencil stuff - needed to get paint-buffer shown too (since it's 2D) */
 			ED_gpencil_draw_view3d(NULL, scene, v3d, ar, false);
@@ -1891,6 +1887,9 @@ void ED_view3d_draw_offscreen(
 	ar->winy = bwiny;
 	ar->winrct = brect;
 
+	glMatrixMode(GL_PROJECTION);
+	gpuPopMatrix();
+	glMatrixMode(GL_MODELVIEW);
 	gpuPopMatrix();
 
 	UI_Theme_Restore(&theme_state);
@@ -2529,6 +2528,13 @@ void view3d_main_region_draw_legacy(const bContext *C, ARegion *ar)
 	bool render_border = ED_view3d_calc_render_border(scene, v3d, ar, &border_rect);
 	bool clip_border = (render_border && !BLI_rcti_compare(&ar->drawrct, &border_rect));
 
+	glMatrixMode(GL_PROJECTION);
+	gpuPushMatrix();
+	gpuLoadIdentity();
+	glMatrixMode(GL_MODELVIEW);
+	gpuPushMatrix();
+	gpuLoadIdentity();
+
 	/* draw viewport using opengl */
 	if (v3d->drawtype != OB_RENDER || !view3d_main_region_do_render_draw(scene) || clip_border) {
 		view3d_main_region_clear(scene, v3d, ar); /* background */
@@ -2547,6 +2553,11 @@ void view3d_main_region_draw_legacy(const bContext *C, ARegion *ar)
 
 	view3d_main_region_draw_info(C, scene, ar, v3d, grid_unit, render_border);
 
+	glMatrixMode(GL_PROJECTION);
+	gpuPopMatrix();
+	glMatrixMode(GL_MODELVIEW);
+	gpuPopMatrix();
+
 	v3d->flag |= V3D_INVALID_BACKBUF;
 
 	BLI_assert(BLI_listbase_is_empty(&v3d->afterdraw_transp));