DRW: Opti: Make cursor use batch instead of immediate API.

This is also much cleaner and taking 1 drawcall instead of 2.

3 files changed, 104 insertions, 53 deletions

diff --git a/source/blender/draw/intern/draw_cache.c b/source/blender/draw/intern/draw_cache.c
index 6b1a3356b51..8fdf1a2fce7 100644
--- a/source/blender/draw/intern/draw_cache.c
+++ b/source/blender/draw/intern/draw_cache.c
@@ -32,6 +32,8 @@
 #include "DNA_modifier_types.h"
 #include "DNA_lattice_types.h"
 
+#include "UI_resources.h"
+
 #include "BLI_utildefines.h"
 #include "BLI_math.h"
 
@@ -43,6 +45,7 @@
 /* Batch's only (free'd as an array) */
 static struct DRWShapeCache {
 	Gwn_Batch *drw_single_vertice;
+	Gwn_Batch *drw_cursor;
 	Gwn_Batch *drw_fullscreen_quad;
 	Gwn_Batch *drw_quad;
 	Gwn_Batch *drw_sphere;
@@ -2709,3 +2712,91 @@ Gwn_Batch *DRW_cache_particles_get_prim(int type)
 
 	return NULL;
 }
+
+/* 3D cursor */
+Gwn_Batch *DRW_cache_cursor_get(void)
+{
+	if (!SHC.drw_cursor) {
+		const float f5 = 0.25f;
+		const float f10 = 0.5f;
+		const float f20 = 1.0f;
+
+		const int segments = 16;
+		const int vert_ct = segments + 8;
+		const int index_ct = vert_ct + 5;
+
+		unsigned char red[3] = {255, 0, 0};
+		unsigned char white[3] = {255, 255, 255};
+		unsigned char crosshair_color[3];
+		UI_GetThemeColor3ubv(TH_VIEW_OVERLAY, crosshair_color);
+
+		static Gwn_VertFormat format = { 0 };
+		static struct { uint pos, color; } attr_id;
+		if (format.attrib_ct == 0) {
+			attr_id.pos = GWN_vertformat_attr_add(&format, "pos", GWN_COMP_F32, 2, GWN_FETCH_FLOAT);
+			attr_id.color = GWN_vertformat_attr_add(&format, "color", GWN_COMP_U8, 3, GWN_FETCH_INT_TO_FLOAT_UNIT);
+		}
+
+		Gwn_IndexBufBuilder elb;
+		GWN_indexbuf_init_ex(&elb, GWN_PRIM_LINE_STRIP, index_ct, vert_ct, true);
+
+		Gwn_VertBuf *vbo = GWN_vertbuf_create_with_format(&format);
+		GWN_vertbuf_data_alloc(vbo, vert_ct);
+
+		int v = 0;
+		for (int i = 0; i < segments; ++i) {
+			float angle = (float)(2 * M_PI) * ((float)i / (float)segments);
+			float x = f10 * cosf(angle);
+			float y = f10 * sinf(angle);
+
+			if (i % 2 == 0)
+				GWN_vertbuf_attr_set(vbo, attr_id.color, v, red);
+			else
+				GWN_vertbuf_attr_set(vbo, attr_id.color, v, white);
+
+			GWN_vertbuf_attr_set(vbo, attr_id.pos, v, (const float[2]){x, y});
+			GWN_indexbuf_add_generic_vert(&elb, v++);
+		}
+		GWN_indexbuf_add_generic_vert(&elb, 0);
+		GWN_indexbuf_add_primitive_restart(&elb);
+
+		GWN_vertbuf_attr_set(vbo, attr_id.pos, v, (const float[2]){-f20, 0});
+		GWN_vertbuf_attr_set(vbo, attr_id.color, v, crosshair_color);
+		GWN_indexbuf_add_generic_vert(&elb, v++);
+		GWN_vertbuf_attr_set(vbo, attr_id.pos, v, (const float[2]){-f5, 0});
+		GWN_vertbuf_attr_set(vbo, attr_id.color, v, crosshair_color);
+		GWN_indexbuf_add_generic_vert(&elb, v++);
+
+		GWN_indexbuf_add_primitive_restart(&elb);
+
+		GWN_vertbuf_attr_set(vbo, attr_id.pos, v, (const float[2]){+f5, 0});
+		GWN_vertbuf_attr_set(vbo, attr_id.color, v, crosshair_color);
+		GWN_indexbuf_add_generic_vert(&elb, v++);
+		GWN_vertbuf_attr_set(vbo, attr_id.pos, v, (const float[2]){+f20, 0});
+		GWN_vertbuf_attr_set(vbo, attr_id.color, v, crosshair_color);
+		GWN_indexbuf_add_generic_vert(&elb, v++);
+
+		GWN_indexbuf_add_primitive_restart(&elb);
+
+		GWN_vertbuf_attr_set(vbo, attr_id.pos, v, (const float[2]){0, -f20});
+		GWN_vertbuf_attr_set(vbo, attr_id.color, v, crosshair_color);
+		GWN_indexbuf_add_generic_vert(&elb, v++);
+		GWN_vertbuf_attr_set(vbo, attr_id.pos, v, (const float[2]){0, -f5});
+		GWN_vertbuf_attr_set(vbo, attr_id.color, v, crosshair_color);
+		GWN_indexbuf_add_generic_vert(&elb, v++);
+
+		GWN_indexbuf_add_primitive_restart(&elb);
+
+		GWN_vertbuf_attr_set(vbo, attr_id.pos, v, (const float[2]){0, +f5});
+		GWN_vertbuf_attr_set(vbo, attr_id.color, v, crosshair_color);
+		GWN_indexbuf_add_generic_vert(&elb, v++);
+		GWN_vertbuf_attr_set(vbo, attr_id.pos, v, (const float[2]){0, +f20});
+		GWN_vertbuf_attr_set(vbo, attr_id.color, v, crosshair_color);
+		GWN_indexbuf_add_generic_vert(&elb, v++);
+
+		Gwn_IndexBuf *ibo = GWN_indexbuf_build(&elb);
+
+		SHC.drw_cursor = GWN_batch_create_ex(GWN_PRIM_LINE_STRIP, vbo, ibo, GWN_BATCH_OWNS_VBO | GWN_BATCH_OWNS_INDEX);
+	}
+	return SHC.drw_cursor;
+}
\ No newline at end of file
diff --git a/source/blender/draw/intern/draw_cache.h b/source/blender/draw/intern/draw_cache.h
index c039bb8883d..60c41ddc798 100644
--- a/source/blender/draw/intern/draw_cache.h
+++ b/source/blender/draw/intern/draw_cache.h
@@ -33,6 +33,9 @@ struct ModifierData;
 
 void DRW_shape_cache_free(void);
 
+/* 3D cursor */
+struct Gwn_Batch *DRW_cache_cursor_get(void);
+
 /* Common Shapes */
 struct Gwn_Batch *DRW_cache_fullscreen_quad_get(void);
 struct Gwn_Batch *DRW_cache_quad_get(void);
diff --git a/source/blender/draw/intern/draw_view.c b/source/blender/draw/intern/draw_view.c
index d9ffbde38e7..f38a7689c06 100644
--- a/source/blender/draw/intern/draw_view.c
+++ b/source/blender/draw/intern/draw_view.c
@@ -645,7 +645,7 @@ void DRW_draw_cursor(void)
 {
 	const DRWContextState *draw_ctx = DRW_context_state_get();
 	View3D *v3d = draw_ctx->v3d;
-	RegionView3D *rv3d = draw_ctx->rv3d;
+	ARegion *ar = draw_ctx->ar;
 	Scene *scene = draw_ctx->scene;
 	ViewLayer *view_layer = draw_ctx->view_layer;
 
@@ -655,61 +655,18 @@ void DRW_draw_cursor(void)
 	glLineWidth(1.0f);
 
 	if (is_cursor_visible(draw_ctx, scene, view_layer)) {
-		float *co = ED_view3d_cursor3d_get(scene, v3d);
-		unsigned char crosshair_color[3];
-
-		const float f5 = 0.25f;
-		const float f10 = 0.5f;
-		const float f20 = 1.0f;
-
-		Gwn_VertFormat *format = immVertexFormat();
-		unsigned int pos = GWN_vertformat_attr_add(format, "pos", GWN_COMP_F32, 2, GWN_FETCH_FLOAT);
-		unsigned int color = GWN_vertformat_attr_add(format, "color", GWN_COMP_U8, 3, GWN_FETCH_INT_TO_FLOAT_UNIT);
-		unsigned int wpos = GWN_vertformat_attr_add(format, "world_pos", GWN_COMP_F32, 3, GWN_FETCH_FLOAT);
+		int co[2];
+		if (ED_view3d_project_int_global(ar, ED_view3d_cursor3d_get(scene, v3d), co, V3D_PROJ_TEST_NOP) == V3D_PROJ_RET_OK) {
 
-		/* XXX Using instance shader without instance */
-		immBindBuiltinProgram(GPU_SHADER_3D_SCREENSPACE_VARIYING_COLOR);
-		immUniform1f("size", U.widget_unit);
-		immUniform1f("pixel_size", *DRW_viewport_pixelsize_get());
-		immUniformArray3fv("screen_vecs", DRW_viewport_screenvecs_get(), 2);
-		immUniformMatrix4fv("ViewProjectionMatrix", rv3d->persmat);
+			ED_region_pixelspace(ar);
+			gpuTranslate2f(co[0], co[1]);
+			gpuScale2f(U.widget_unit, U.widget_unit);
 
-		const int segments = 16;
-
-		immBegin(GWN_PRIM_LINE_LOOP, segments);
-		immAttrib3fv(wpos, co);
-
-		for (int i = 0; i < segments; ++i) {
-			float angle = (float)(2 * M_PI) * ((float)i / (float)segments);
-			float x = f10 * cosf(angle);
-			float y = f10 * sinf(angle);
-
-			if (i % 2 == 0)
-				immAttrib3ub(color, 255, 0, 0);
-			else
-				immAttrib3ub(color, 255, 255, 255);
-
-			immVertex2f(pos, x, y);
+			Gwn_Batch *cursor_batch = DRW_cache_cursor_get();
+			GPUShader *shader = GPU_shader_get_builtin_shader(GPU_SHADER_2D_FLAT_COLOR);
+			GWN_batch_program_set(cursor_batch, GPU_shader_get_program(shader), GPU_shader_get_interface(shader));
+			GWN_batch_draw(cursor_batch);
 		}
-		immEnd();
-
-		UI_GetThemeColor3ubv(TH_VIEW_OVERLAY, crosshair_color);
-
-		immBegin(GWN_PRIM_LINES, 8);
-		immAttrib3ubv(color, crosshair_color);
-		immAttrib3fv(wpos, co);
-
-		immVertex2f(pos, -f20, 0);
-		immVertex2f(pos, -f5, 0);
-		immVertex2f(pos, +f5, 0);
-		immVertex2f(pos, +f20, 0);
-		immVertex2f(pos, 0, -f20);
-		immVertex2f(pos, 0, -f5);
-		immVertex2f(pos, 0, +f5);
-		immVertex2f(pos, 0, +f20);
-		immEnd();
-
-		immUnbindProgram();
 	}
 }