lib/gamnit: intro draw_mode

This is very useful to create optimized Mesh, using gl_TRIANGLE_STRIP and gl_TRIANGLE_FAN.

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/lib/gamnit/depth/depth_core.nit b/lib/gamnit/depth/depth_core.nit
index 03a3970..f1e5803 100644 (file)
--- a/lib/gamnit/depth/depth_core.nit
+++ b/lib/gamnit/depth/depth_core.nit
@@ -103,6 +103,9 @@ class Mesh
        # Coordinates on the texture per vertex
        var texture_coords = new Array[Float] is lazy, writable
 
+       # `GLDrawMode` used to display this mesh, defaults to `gl_TRIANGLES`
+       fun draw_mode: GLDrawMode do return gl_TRIANGLES
+
        # Create an UV sphere of `radius` with `n_meridians` and `n_parallels`
        init uv_sphere(radius: Float, n_meridians, n_parallels: Int)
        do

diff --git a/lib/gamnit/depth/more_materials.nit b/lib/gamnit/depth/more_materials.nit
index 6117128..b77c85e 100644 (file)
--- a/lib/gamnit/depth/more_materials.nit
+++ b/lib/gamnit/depth/more_materials.nit
@@ -75,9 +75,9 @@ class SmoothMaterial
 
                # Execute draw
                if mesh.indices.is_empty then
-                       glDrawArrays(gl_TRIANGLES, 0, mesh.vertices.length/3)
+                       glDrawArrays(mesh.draw_mode, 0, mesh.vertices.length/3)
                else
-                       glDrawElements(gl_TRIANGLES, mesh.indices.length, gl_UNSIGNED_SHORT, mesh.indices_c.native_array)
+                       glDrawElements(mesh.draw_mode, mesh.indices.length, gl_UNSIGNED_SHORT, mesh.indices_c.native_array)
                end
        end
 end
@@ -182,9 +182,9 @@ class TexturedMaterial
                program.camera.uniform(app.world_camera.position.x, app.world_camera.position.y, app.world_camera.position.z)
 
                if mesh.indices.is_empty then
-                       glDrawArrays(gl_TRIANGLES, 0, mesh.vertices.length/3)
+                       glDrawArrays(mesh.draw_mode, 0, mesh.vertices.length/3)
                else
-                       glDrawElements(gl_TRIANGLES, mesh.indices.length, gl_UNSIGNED_SHORT, mesh.indices_c.native_array)
+                       glDrawElements(mesh.draw_mode, mesh.indices.length, gl_UNSIGNED_SHORT, mesh.indices_c.native_array)
                end
        end
 end
@@ -220,9 +220,9 @@ class NormalsMaterial
                program.normal.array(mesh.normals, 3)
 
                if mesh.indices.is_empty then
-                       glDrawArrays(gl_TRIANGLES, 0, mesh.vertices.length/3)
+                       glDrawArrays(mesh.draw_mode, 0, mesh.vertices.length/3)
                else
-                       glDrawElements(gl_TRIANGLES, mesh.indices.length, gl_UNSIGNED_SHORT, mesh.indices_c.native_array)
+                       glDrawElements(mesh.draw_mode, mesh.indices.length, gl_UNSIGNED_SHORT, mesh.indices_c.native_array)
                end
        end
 end