Materials for paged atlas support (#7581)

* Added sprite and particlefx paged materials + shaders

* Use lowp instead

engine/engine/content/builtins/materials/particlefx_paged_atlas.fp

@@ -0,0 +1,14 @@
+varying mediump vec2 var_texcoord0;
+varying lowp vec4    var_color;
+varying lowp float   var_page_index;
+
+uniform lowp sampler2DArray texture_sampler;
+uniform lowp vec4           tint;
+
+void main()
+{
+    // Pre-multiply alpha since all runtime textures already are
+    lowp vec4 tint_pm = vec4(tint.xyz * tint.w, tint.w);
+    // var_color is vertex color from the particle system, pre-multiplied in vertex program
+    gl_FragColor = texture2DArray(texture_sampler, vec3(var_texcoord0.xy, var_page_index)) * var_color * tint_pm;
+}

engine/engine/content/builtins/materials/particlefx_paged_atlas.material

@@ -0,0 +1,14 @@
+name: "particle_paged_atlas"
+vertex_program: "/builtins/materials/particlefx_paged_atlas.vp"
+fragment_program: "/builtins/materials/particlefx_paged_atlas.fp"
+tags: "particle"
+vertex_constants {
+  name: "view_proj"
+  type: CONSTANT_TYPE_VIEWPROJ
+}
+fragment_constants {
+  name: "tint"
+  type: CONSTANT_TYPE_USER
+  value: {x: 1 y: 1 z: 1 w: 1}
+}
+max_page_count: 4

engine/engine/content/builtins/materials/particlefx_paged_atlas.vp

@@ -0,0 +1,19 @@
+uniform highp mat4 view_proj;
+
+// positions are in world space
+attribute highp vec4   position;
+attribute mediump vec2 texcoord0;
+attribute lowp vec4    color;
+attribute lowp float   page_index;
+
+varying mediump vec2 var_texcoord0;
+varying lowp vec4    var_color;
+varying lowp float   var_page_index;
+
+void main()
+{
+    gl_Position    = view_proj * vec4(position.xyz, 1.0);
+    var_texcoord0  = texcoord0;
+    var_color      = vec4(color.rgb * color.a, color.a);
+    var_page_index = page_index;
+}

engine/engine/content/builtins/materials/sprite_paged_atlas.fp

@@ -0,0 +1,12 @@
+varying mediump vec2 var_texcoord0;
+varying lowp float   var_page_index;
+
+uniform lowp sampler2DArray texture_sampler;
+uniform lowp vec4           tint;
+
+void main()
+{
+    // Pre-multiply alpha since all runtime textures already are
+    lowp vec4 tint_pm = vec4(tint.xyz * tint.w, tint.w);
+    gl_FragColor      = texture2DArray(texture_sampler, vec3(var_texcoord0.xy, var_page_index)) * tint_pm;
+}

engine/engine/content/builtins/materials/sprite_paged_atlas.material

@@ -0,0 +1,14 @@
+name: "sprite_paged_atlas"
+vertex_program: "/builtins/materials/sprite_paged_atlas.vp"
+fragment_program: "/builtins/materials/sprite_paged_atlas.fp"
+tags: "tile"
+vertex_constants {
+  name: "view_proj"
+  type: CONSTANT_TYPE_VIEWPROJ
+}
+fragment_constants {
+  name: "tint"
+  type: CONSTANT_TYPE_USER
+  value: {x: 1 y: 1 z: 1 w: 1}
+}
+max_page_count: 4

engine/engine/content/builtins/materials/sprite_paged_atlas.vp

@@ -0,0 +1,16 @@
+uniform highp mat4 view_proj;
+
+// positions are in world space
+attribute highp vec4   position;
+attribute mediump vec2 texcoord0;
+attribute lowp float   page_index;
+
+varying mediump vec2 var_texcoord0;
+varying lowp float   var_page_index;
+
+void main()
+{
+    gl_Position    = view_proj * vec4(position.xyz, 1.0);
+    var_texcoord0  = texcoord0;
+    var_page_index = page_index;
+}