Render: add "OpenGL" render engine.

This is intended for quick renders for previsualization, animation previews
or sequencer previews. It provides the same settings as found in the 3D view
Shading popover in solid display mode, but in the scene render properties.

The "Workbench" engine was removed, and this name no longer appears in the
user interface, it's purely an internal name. We might come up with a better
name for this OpenGL engine still, but it's good to be consistent with the
OpenGL Render operator name since this has a similar purpose.

1 files changed, 172 insertions, 0 deletions

diff --git a/source/blender/draw/engines/workbench/workbench_render.c b/source/blender/draw/engines/workbench/workbench_render.c
new file mode 100644
index 00000000000..1b25d4c875c
--- /dev/null
+++ b/source/blender/draw/engines/workbench/workbench_render.c
@@ -0,0 +1,172 @@
+/*
+ * Copyright 2016, Blender Foundation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Contributor(s): Blender Institute
+ *
+ */
+
+/** \file workbench_render.c
+ *  \ingroup draw_engine
+ *
+ * Render functions for final render output.
+ */
+
+#include "BLI_rect.h"
+
+#include "BKE_report.h"
+
+#include "DRW_render.h"
+
+#include "GPU_shader.h"
+
+#include "DEG_depsgraph.h"
+#include "DEG_depsgraph_query.h"
+
+#include "RE_pipeline.h"
+
+#include "workbench_private.h"
+
+static void workbench_render_cache(
+        void *vedata, struct Object *ob,
+        struct RenderEngine *UNUSED(engine), struct Depsgraph *UNUSED(depsgraph))
+{
+	workbench_deferred_solid_cache_populate(vedata, ob);
+}
+
+static void workbench_render_matrices_init(RenderEngine *engine, Depsgraph *depsgraph)
+{
+	/* TODO(sergey): Shall render hold pointer to an evaluated camera instead? */
+	Scene *scene = DEG_get_evaluated_scene(depsgraph);
+	struct Object *ob_camera_eval = DEG_get_evaluated_object(depsgraph, RE_GetCamera(engine->re));
+	float frame = BKE_scene_frame_get(scene);
+
+	/* Set the persective, view and window matrix. */
+	float winmat[4][4], wininv[4][4];
+	float viewmat[4][4], viewinv[4][4];
+	float persmat[4][4], persinv[4][4];
+
+	RE_GetCameraWindow(engine->re, ob_camera_eval, frame, winmat);
+	RE_GetCameraModelMatrix(engine->re, ob_camera_eval, viewinv);
+
+	invert_m4_m4(viewmat, viewinv);
+	mul_m4_m4m4(persmat, winmat, viewmat);
+	invert_m4_m4(persinv, persmat);
+	invert_m4_m4(wininv, winmat);
+
+	DRW_viewport_matrix_override_set(persmat, DRW_MAT_PERS);
+	DRW_viewport_matrix_override_set(persinv, DRW_MAT_PERSINV);
+	DRW_viewport_matrix_override_set(winmat, DRW_MAT_WIN);
+	DRW_viewport_matrix_override_set(wininv, DRW_MAT_WININV);
+	DRW_viewport_matrix_override_set(viewmat, DRW_MAT_VIEW);
+	DRW_viewport_matrix_override_set(viewinv, DRW_MAT_VIEWINV);
+}
+
+static bool workbench_render_framebuffers_init(void)
+{
+	/* For image render, allocate own buffers because we don't have a viewport. */
+	const float *viewport_size = DRW_viewport_size_get();
+	const int size[2] = {(int)viewport_size[0], (int)viewport_size[1]};
+
+	DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
+	dtxl->color = GPU_texture_create_2D(size[0], size[1], GPU_RGBA8, NULL, NULL);
+	dtxl->depth = GPU_texture_create_2D(size[0], size[1], GPU_DEPTH24_STENCIL8, NULL, NULL);
+
+	if (!(dtxl->depth && dtxl->color)) {
+		return false;
+	}
+
+	DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
+
+	GPU_framebuffer_ensure_config(&dfbl->default_fb, {
+		GPU_ATTACHMENT_TEXTURE(dtxl->depth),
+		GPU_ATTACHMENT_TEXTURE(dtxl->color)
+	});
+
+	GPU_framebuffer_ensure_config(&dfbl->depth_only_fb, {
+		GPU_ATTACHMENT_TEXTURE(dtxl->depth),
+		GPU_ATTACHMENT_NONE
+	});
+
+	GPU_framebuffer_ensure_config(&dfbl->color_only_fb, {
+		GPU_ATTACHMENT_NONE,
+		GPU_ATTACHMENT_TEXTURE(dtxl->color)
+	});
+
+	bool ok = true;
+	ok = ok && GPU_framebuffer_check_valid(dfbl->default_fb, NULL);
+	ok = ok && GPU_framebuffer_check_valid(dfbl->color_only_fb, NULL);
+	ok = ok && GPU_framebuffer_check_valid(dfbl->depth_only_fb, NULL);
+
+	return ok;
+}
+
+static void workbench_render_framebuffers_finish(void)
+{
+}
+
+void workbench_render(WORKBENCH_Data *data, RenderEngine *engine, RenderLayer *render_layer, const rcti *rect)
+{
+	const DRWContextState *draw_ctx = DRW_context_state_get();
+
+	Depsgraph *depsgraph = draw_ctx->depsgraph;
+	workbench_render_matrices_init(engine, depsgraph);
+
+	if (!workbench_render_framebuffers_init()) {
+		RE_engine_report(engine, RPT_ERROR, "Failed to allocate OpenGL buffers");
+		return;
+	}
+
+	/* Init engine. */
+	workbench_deferred_engine_init(data);
+
+	/* Init objects. */
+	workbench_deferred_cache_init(data);
+	DRW_render_object_iter(data, engine, depsgraph, workbench_render_cache);
+	workbench_deferred_cache_finish(data);
+	DRW_render_instance_buffer_finish();
+
+	/* Draw. */
+	int num_samples = workbench_taa_calculate_num_iterations(data);
+	for (int sample = 0; sample < num_samples; sample++) {
+		if (RE_engine_test_break(engine)) {
+			break;
+		}
+
+		workbench_deferred_draw_background(data);
+		workbench_deferred_draw_scene(data);
+	}
+
+	workbench_deferred_draw_finish(data);
+
+	/* Write render output. */
+	const char *viewname = RE_GetActiveRenderView(engine->re);
+	RenderPass *rp = RE_pass_find_by_name(render_layer, RE_PASSNAME_COMBINED, viewname);
+
+	DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
+	GPU_framebuffer_bind(dfbl->color_only_fb);
+	GPU_framebuffer_read_color(dfbl->color_only_fb,
+	                           rect->xmin, rect->ymin,
+	                           BLI_rcti_size_x(rect), BLI_rcti_size_y(rect),
+	                           4, 0, rp->rect);
+
+	workbench_render_framebuffers_finish();
+}
+
+void workbench_render_update_passes(RenderEngine *engine, Scene *scene, ViewLayer *view_layer)
+{
+	RE_engine_register_pass(engine, scene, view_layer, RE_PASSNAME_COMBINED, 4, "RGBA", SOCK_RGBA);
+}