PixelateMask Shader

game/scripts/shaders.rpy

@@ -34,6 +34,63 @@ init python:
         gl_FragColor = vec4(mix(gl_FragColor.xyz, gl_FragColor.xyz * ctemp2rgb(ctemp), u_strength), 1.0);
     """)
 
+    renpy.register_shader("pixelatemaskshader", variables="""
+        uniform sampler2D tex0;
+        uniform sampler2D tex1;
+        uniform vec2 res0;
+        uniform float u_step;
+        uniform float u_lod_bias;
+        attribute vec2 a_tex_coord;
+        varying vec2 v_tex_coord;
+    """, vertex_600="""
+        v_tex_coord = a_tex_coord;
+    """, fragment_functions="""
+        vec2 CalculateNewUV(vec2 uv, vec2 size, float step) {
+            float dx = (step / size.x);
+            float dy = (step / size.y);
+            return vec2(dx*(floor(uv.x/dx) + 0.5), dy*(floor(uv.y/dy) + 0.5));
+        }
+
+        vec4 PixelateMask(sampler2D source, float alpha, vec2 size, vec2 uv, float step, float lod) {
+            if (alpha > 0.0) {
+                vec2 new_uv = CalculateNewUV(uv, size, step);
+                vec4 old = vec4(texture2D(source, uv, lod).rgb, 1.0);
+                vec4 new = vec4(texture2D(source, new_uv, lod).rgb, 1.0);
+                return mix(old, new, alpha);
+            }
+
+            return texture2D(source, uv, lod);
+        }
+    """, fragment_600="""
+        float alpha = texture2D(tex1, v_tex_coord).a;
+        gl_FragColor = PixelateMask(tex0, alpha, res0, v_tex_coord, u_step, u_lod_bias);
+        """)
+
+    class PixelateMask(renpy.Displayable, NoRollback):
+        def __init__(self, child, mask, step=1.0, **kwargs):
+            super().__init__(**kwargs)
+            self.child = renpy.displayable(child)
+            self.mask = renpy.displayable(mask)
+            self.step = step
+
+        def render(self, width, height, st, at):
+            child = renpy.display.render.render(self.child, width, height, st, at)
+            mask = renpy.display.render.render(self.mask, width, height, st, at)
+
+            rv = renpy.display.render.Render(width, height)
+
+            if renpy.display.render.models:
+
+                rv.mesh = True
+                rv.add_shader("pixelatemaskshader")
+                rv.add_uniform("u_step", self.step)
+
+            rv.blit(child, (0, 0))
+            rv.blit(mask, (0, 0))
+
+            renpy.redraw(self, 0)
+            return rv
+
 transform color_temperature(factor=1.0, strength=1.0):
     mesh True
     shader "color_temperature_shader"