Implemented draw order for immediate mode rendering

src/game/editor.c

@@ -122,7 +122,7 @@ void editor_init(struct Editor* editor)
 	vec3_fill(&editor->tool_mesh_position, 0.f, 0.f, 0.f);
 	vec4_fill(&editor->tool_mesh_color, 0.f, 0.3f, 1.f, 1.f);
 	vec4_fill(&editor->selected_entity_colour, 0.f, 1.f, 0.f, 1.f);
-	vec4_fill(&editor->grid_color, 0.3f, 0.3f, 0.3f, 1.f);
+	vec4_fill(&editor->grid_color, 0.3f, 0.3f, 0.3f, 0.5f);
     debug_vars_list                   = array_new(struct Debug_Variable);
     empty_indices                     = array_new(int);
 	
@@ -187,7 +187,7 @@ void editor_render(struct Editor* editor, struct Camera * active_camera)
 			transform_get_absolute_rot(editor->selected_entity, &rotation);
 		}
 
-		im_begin(position, rotation, scale, editor->grid_color, GDM_LINES);
+		im_begin(position, rotation, scale, editor->grid_color, GDM_LINES, 0);
 
 		float half_grid = editor->grid_num_lines * editor->grid_scale / 2.f;
 		for(float i = 0; i <= editor->grid_num_lines * editor->grid_scale; i += editor->grid_scale)
@@ -432,10 +432,10 @@ void editor_update(struct Editor* editor, float dt)
 	{
 		if(editor->current_mode == EDITOR_MODE_TRANSLATE)
 		{
-			im_sphere(0.5f, editor->tool_mesh_position, (quat) { 0.f, 0.f, 0.f, 1.f }, editor->tool_mesh_color, GDM_TRIANGLES);
+			im_sphere(0.5f, editor->tool_mesh_position, (quat) { 0.f, 0.f, 0.f, 1.f }, editor->tool_mesh_color, GDM_TRIANGLES, 2);
 			//im_box(editor->grid_scale, editor->grid_scale, editor->grid_scale, editor->tool_mesh_position, (quat) { 0.f, 0.f, 0.f, 1.f }, editor->tool_mesh_color, GDM_TRIANGLES);
 
-			im_begin(editor->tool_mesh_position, (quat) { 0.f, 0.f, 0.f, 1.f }, (vec3) { 1.f, 1.f, 1.f }, (vec4) { 0.f, 1.f, 1.f, 1.f }, GDM_LINES);
+			im_begin(editor->tool_mesh_position, (quat) { 0.f, 0.f, 0.f, 1.f }, (vec3) { 1.f, 1.f, 1.f }, (vec4) { 0.f, 1.f, 1.f, 1.f }, GDM_LINES, 3);
 			switch(editor->current_axis)
 			{
 			case EDITOR_AXIS_XZ:

src/game/game.c

@@ -408,7 +408,7 @@ void game_debug(float dt)
     quat im_rot      = { 0.f, 0.f, 0.f, 1.f };
     vec4 im_color    = { 0.f, 1.f, 1.f, 1.f };
     quat_identity(&im_rot);
-    im_begin(im_position, im_rot, im_scale, im_color, GL_LINES);
+    im_begin(im_position, im_rot, im_scale, im_color, GDM_LINES, 1);
 
     im_pos(0.f, 0.f, 0.f);
     im_pos(100.f, 100.f, 10.f);
@@ -419,7 +419,7 @@ void game_debug(float dt)
 
     im_color.x = 1.f;
     im_color.y = 0.f;
-    im_begin(im_position, im_rot, im_scale, im_color, GL_TRIANGLES);
+    im_begin(im_position, im_rot, im_scale, im_color, GL_TRIANGLES, 1);
 
     float length = 200.f;
 
@@ -458,7 +458,7 @@ void game_debug(float dt)
     im_end();
 
     im_position.x = -30.f;
-    im_begin(im_position, im_rot, im_scale, im_color, GL_LINES);
+    im_begin(im_position, im_rot, im_scale, im_color, GL_LINES, 1);
 
     im_pos(0.f, 0.f, 0.f);
     im_pos(0.f, 0.f, 10.f);
@@ -475,12 +475,12 @@ void game_debug(float dt)
     im_end();
 
     vec4 prim_color = {1.f, 1.f, 0.f, 1.f};
-    im_box(5.f, 2.f, 10.f, im_position, im_rot, prim_color, GDM_TRIANGLES);
+    im_box(5.f, 2.f, 10.f, im_position, im_rot, prim_color, GDM_TRIANGLES, 1);
 
     for(int i = 0; i < 10; i++)
     {
 		im_position.x += i * 2.f;
-		im_sphere(2.f, im_position, im_rot, prim_color, GDM_TRIANGLES);
+		im_sphere(2.f, im_position, im_rot, prim_color, GDM_TRIANGLES, 1);
     }
 }
 
@@ -1868,7 +1868,7 @@ void game_debug_gui(float dt)
 
 void game_render(void)
 {
-    renderer_draw(game_state->renderer, game_state->scene);
+    renderer_render(game_state->renderer, game_state->scene);
 }
 
 void game_cleanup(void)

src/game/im_render.c

@@ -9,6 +9,7 @@
 #include "geometry.h"
 
 #include <string.h>
+#include <stdlib.h>
 
 #define MAX_IM_VERTICES 2048
 #define MAX_IM_GEOMETRIES (MAX_IM_VERTICES / 2)
@@ -29,6 +30,7 @@ static struct IM_Geom* active_geom = NULL;
 static int active_vertex_index    = 0;
 
 static void im_geom_reset(struct IM_Geom* geom);
+static int  im_sort_func(const void* p1, const void* p2);
 
 void im_init(void)
 {
@@ -74,7 +76,7 @@ void im_cleanup(void)
 	IM_State.im_shader   = -1;
 }
 
-void im_begin(vec3 position, quat rotation, vec3 scale, vec4 color, int draw_mode)
+void im_begin(vec3 position, quat rotation, vec3 scale, vec4 color, int draw_mode, int draw_order)
 {
 	if(active_geom)
 	{
@@ -87,6 +89,7 @@ void im_begin(vec3 position, quat rotation, vec3 scale, vec4 color, int draw_mod
 	active_geom->start_index = IM_State.curr_vertex;
 	active_geom->type = IGT_DYNAMIC;
 	active_geom->draw_mode = draw_mode;
+	active_geom->draw_order = draw_order;
 	vec3_assign(&active_geom->position, &position);
 	vec3_assign(&active_geom->scale, &scale);
 	vec4_assign(&active_geom->color, &color);
@@ -105,7 +108,7 @@ void im_pos(float x, float y, float z)
 	active_vertex_index++;
 }
 
-void im_box(float x, float y, float z, vec3 position, quat rotation, vec4 color, int draw_mode)
+void im_box(float x, float y, float z, vec3 position, quat rotation, vec4 color, int draw_mode, int draw_order)
 {
 	if(active_geom)
 	{
@@ -117,6 +120,7 @@ void im_box(float x, float y, float z, vec3 position, quat rotation, vec4 color,
 	im_geom_reset(active_geom);
 	active_geom->type = IGT_PRIMITIVE;
 	active_geom->draw_mode = draw_mode;
+	active_geom->draw_order = draw_order;
 	active_geom->prim_geom_index = geom_create_from_file("cube.symbres");
 	vec3_assign(&active_geom->position, &position);
 	vec3 scale =  { x, y, z}; 
@@ -126,7 +130,7 @@ void im_box(float x, float y, float z, vec3 position, quat rotation, vec4 color,
 	active_geom = NULL;
 }
 
-void im_sphere(float radius, vec3 position, quat rotation, vec4 color, int draw_mode)
+void im_sphere(float radius, vec3 position, quat rotation, vec4 color, int draw_mode, int draw_order)
 {
 	if(active_geom)
 	{
@@ -138,6 +142,7 @@ void im_sphere(float radius, vec3 position, quat rotation, vec4 color, int draw_
 	im_geom_reset(active_geom);
 	active_geom->type = IGT_PRIMITIVE;
 	active_geom->draw_mode = draw_mode;
+	active_geom->draw_order = draw_order;
 	active_geom->prim_geom_index = geom_create_from_file("sphere.symbres");
 	vec3_assign(&active_geom->position, &position);
 	vec3 scale =  { radius, radius, radius }; 
@@ -167,6 +172,10 @@ void im_render(struct Camera* active_viewer)
 	if(IM_State.curr_geom == -1)
 		return;
 
+	/* Sort by draw order, geometries with lower draw order get drawn first */
+	if(IM_State.curr_geom + 1 > 1)
+		qsort(IM_State.geometries, IM_State.curr_geom + 1, sizeof(struct IM_Geom), &im_sort_func);
+	
 	shader_bind(IM_State.im_shader);
 	{
 		static mat4 mvp, translation, rotation, scale;
@@ -224,4 +233,18 @@ void im_geom_reset(struct IM_Geom* geom)
 	geom->num_vertices = 0;
 	geom->prim_geom_index = -1;
 	geom->draw_mode = -1;
+	geom->draw_order = -1;
+}
+
+int im_sort_func(const void* p1, const void* p2)
+{
+	struct IM_Geom* g1 = (struct IM_Geom*)p1;
+	struct IM_Geom* g2 = (struct IM_Geom*)p2;
+	if(g1->draw_order < g2->draw_order)
+		return -1;
+	else if(g1->draw_order == g2->draw_order)
+		return 0;
+	else
+		return 1;
 }
+

src/game/im_render.h

@@ -32,16 +32,17 @@ struct IM_Geom
 		
 	};
 	int draw_mode;
+	int draw_order;
 };
 
 struct Camera;
 
 void im_init(void);
 void im_cleanup(void);
-void im_begin(vec3 position, quat rotation, vec3 scale, vec4 color, int draw_mode);
+void im_begin(vec3 position, quat rotation, vec3 scale, vec4 color, int draw_mode, int draw_order);
 void im_pos(float x, float y, float z);
-void im_box(float x, float y, float z, vec3 position, quat rotation, vec4 color, int draw_mode);
+void im_box(float x, float y, float z, vec3 position, quat rotation, vec4 color, int draw_mode, int draw_order);
-void im_sphere(float radius, vec3 position, quat rotation, vec4 color, int draw_mode);
+void im_sphere(float radius, vec3 position, quat rotation, vec4 color, int draw_mode, int draw_order);
 void im_end(void);
 void im_render(struct Camera* active_viewer);
 

src/game/renderer.c

@@ -144,7 +144,7 @@ void renderer_init(struct Renderer* renderer)
     }
 }
 
-void renderer_draw(struct Renderer* renderer, struct Scene* scene)
+void renderer_render(struct Renderer* renderer, struct Scene* scene)
 {
     /* Render each camera output into it's framebuffer or to the default framebuffer */
     for(int i = 0; i < MAX_CAMERAS; i++)
@@ -394,14 +394,14 @@ void renderer_draw(struct Renderer* renderer, struct Scene* scene)
 			case CST_SPHERE:
 			{
 				float radius = physics_cs_sphere_radius_get(mesh->collision.collision_shape);
-				im_sphere(radius, pos, rot, physics_draw_color, GDM_TRIANGLES);
+				im_sphere(radius, pos, rot, physics_draw_color, GDM_TRIANGLES, 1);
 			}
 			break;
 			case CST_BOX:
 			{
 				float x = 0.f, y = 0.f, z = 0.f;
 				physics_cs_box_params_get(mesh->collision.collision_shape, &x, &y, &z);
-				im_box(x, y, z, pos, rot, physics_draw_color, GDM_TRIANGLES);
+				im_box(x, y, z, pos, rot, physics_draw_color, GDM_TRIANGLES, 1);
 			};
 			break;
 			default: break;
@@ -442,12 +442,13 @@ void renderer_draw(struct Renderer* renderer, struct Scene* scene)
 				quat abs_rot;
 				transform_get_absolute_position(game_state->editor->selected_entity, &abs_pos);
 				transform_get_absolute_rot(game_state->editor->selected_entity, &abs_rot);
-				im_sphere(1.f, abs_pos, abs_rot, game_state->editor->selected_entity_colour, GDM_TRIANGLES);
+				im_sphere(1.f, abs_pos, abs_rot, game_state->editor->selected_entity_colour, GDM_TRIANGLES, 1);
 			}
 		}
 	}
 
     //Immediate mode geometry render
+	// Maybe try binding the old frame buffer, clear the drawing but let the depth buffer remain to check depth?
     im_render(active_camera);
 
     /* Render 2D stuff */

src/game/renderer.h

@@ -52,7 +52,7 @@ struct Renderer
 };
 
 void renderer_init(struct Renderer* renderer);
-void renderer_draw(struct Renderer* renderer, struct Scene* scene);
+void renderer_render(struct Renderer* renderer, struct Scene* scene);
 void renderer_cleanup(struct Renderer* renderer);
 void renderer_clearcolor_set(float r, float g, float b, float a);
 void renderer_debug_draw_enabled(struct Renderer* renderer, bool enabled);

todo.txt

@@ -1,6 +1,4 @@
 Todo:
-	- Add pre-render/post-render steps to deal with render order issues and culling lights before rendering
-	- Immediate mode render order, drawing axis and helpers on top of grid
 	- Better, more accurate picking
 	- Highlight if we are about to select an entity or perform the tool action like translate when mouse is hovered and an entity can be selected at that location
 	- Display the projected position if we perform the action for example display what the new location would be right next to the tool mesh
@@ -238,4 +236,5 @@ Done:
 	* Display editor camera parameter adjustment in top bar
 	* Display Transform mode selection in top bar
 	* Display Axis selection in top bar
+	* Immediate mode render order, drawing axis and helpers on top of grid