play with FoW

Author: gajop

scen_edit/view/map/terrain_settings_editor.lua

@@ -194,6 +194,7 @@ function TerrainSettingsEditor:init()
                     local shaderDef = VFS.Include(shaderFile, envTbl)
                     Spring.SetMapShader(shaderDef.shader, shaderDef.shader)
                     SB.DrawGroundPreForward = shaderDef.DrawGroundPreForward
+                    SB.DrawWorld = shaderDef.DrawWorld
                 end)
                 if not success then
                     Log.Error(msg)

scen_edit/widget.lua

@@ -223,6 +223,10 @@ function widget:DrawWorld()
     end
     SB.executeDelayed("DrawWorld")
     SB.displayUtil:Draw()
+    -- HACK
+    if SB.DrawWorld ~= nil then
+        SB.DrawWorld()
+    end
 end
 
 function widget:DrawWorldPreUnit()
@@ -233,6 +237,7 @@ function widget:DrawWorldPreUnit()
 end
 
 function widget:DrawGroundPreForward()
+    -- HACK
     if SB.DrawGroundPreForward ~= nil then
         SB.DrawGroundPreForward()
     end

springboard/assets/core/shaders/fog_of_war/fow.frag

@@ -0,0 +1,19 @@
+#version 110
+
+uniform sampler2D customSampler;
+uniform sampler2D texSampler;
+uniform vec2 customSamplerSize;
+
+varying vec4 vertexWorldPos;
+varying vec2 texCoors;
+
+void main(void) {
+    float fow = texture2D(customSampler, vertexWorldPos.xz / customSamplerSize).r;
+    gl_FragColor = texture2D(texSampler, texCoors);
+    gl_FragColor.rgb = mix(vec3(0.0), gl_FragColor.rgb, fow);
+
+    // show height (since we don't have any lighting)
+    float heightFactor = max(0.5, vertexWorldPos.y / 100.0);
+    heightFactor = min(1.5, heightFactor);
+    gl_FragColor.rgb *= heightFactor;
+}

springboard/assets/core/shaders/fog_of_war/fow.lua

@@ -0,0 +1,45 @@
+local dir = Path.ExtractDir(__path__)
+local shader = Shaders.Compile({
+    vertex = VFS.LoadFile(Path.Join(dir, "fow.vert")),
+    fragment = VFS.LoadFile(Path.Join(dir, "fow.frag")),
+    uniformInt = {
+        texSampler = 0,
+        customSampler = 1,
+    },
+    uniform = {
+        customSamplerSize = { Game.mapSizeX, Game.mapSizeZ },
+    },
+}, "Custom Map Shader")
+
+
+local texInfo = gl.TextureInfo("$info_los")
+local FOW_TEX = gl.CreateTexture(texInfo.xsize, texInfo.ysize, {
+    fbo = true,
+    min_filter = GL.LINEAR,
+    mag_filter = GL.LINEAR,
+    wrap_s = GL.CLAMP_TO_EDGE,
+    wrap_t = GL.CLAMP_TO_EDGE,
+})
+
+local function Blit(tex1, tex2)
+    gl.Blending("add")
+    gl.Texture(tex1)
+    gl.RenderToTexture(tex2, function()
+        gl.TexRect(-1,-1, 1, 1, 0, 0, 1, 1)
+    end)
+    gl.Texture(false)
+end
+
+local function DrawWorld()
+    Blit("$info_los", FOW_TEX)
+end
+
+local function DrawGroundPreForward()
+    gl.Texture(1, FOW_TEX)
+end
+
+return {
+    shader = shader,
+    DrawGroundPreForward = DrawGroundPreForward,
+    DrawWorld = DrawWorld,
+}

springboard/assets/core/shaders/fog_of_war/fow.vert

@@ -0,0 +1,14 @@
+#version 110
+
+#define SMF_TEXSQR_SIZE 1024.0
+
+uniform ivec2 texSquare;
+
+varying vec4 vertexWorldPos;
+varying vec2 texCoors;
+
+void main(void) {
+    vertexWorldPos = gl_Vertex;
+    texCoors = (floor(gl_Vertex.xz) / SMF_TEXSQR_SIZE) - vec2(texSquare);
+    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
+}