feat: Texture blending (transparency)

FIXES #56

Author: jerthz

examples/tetris/main.rs

@@ -1,34 +1,20 @@
+use scion::game_layer::{GameLayer, GameLayerController, SimpleGameLayer};
+use scion::legion::{Resources, system, World};
+use scion::rendering::bidimensional::{Camera2D, Material2D, Position2D, Transform2D};
+use scion::rendering::bidimensional::components::Square;
 use scion::Scion;
-use scion::legion::{system, World, Resources};
-use scion::game_layer::{SimpleGameLayer, GameLayer, GameLayerController};
 
 #[system]
-fn test(){
+fn test() {
     log::info!("Hello all");
 }
 
 #[derive(Default)]
-struct LayerA{
-    tmp: usize
-}
+struct LayerA;
 
-impl SimpleGameLayer for LayerA{
-    fn update(&mut self, _world: &mut World, resource: &mut Resources) {
-        log::info!("HeullohA...{}", self.tmp);
-        self.tmp += 1;
-        if self.tmp >= 301 {
-            resource.get_mut::<GameLayerController>().unwrap().pop_layer();
-            resource.get_mut::<GameLayerController>().unwrap().push_layer(GameLayer::strong::<LayerB>());
-        }
-    }
-}
-
-#[derive(Default)]
-struct LayerB;
+impl SimpleGameLayer for LayerA {
+    fn on_start(&mut self, world: &mut World, resource: &mut Resources) {
 
-impl SimpleGameLayer for LayerB{
-    fn update(&mut self, _world: &mut World, _resource: &mut Resources) {
-        log::info!("HeullohB...");
     }
 }
 

src/rendering/bidimensional/components/square.rs

@@ -1,8 +1,6 @@
 use std::ops::Range;
 
-use wgpu::{
-    util::BufferInitDescriptor, BindGroupLayout, Device, RenderPipeline, SwapChainDescriptor,
-};
+use wgpu::{util::BufferInitDescriptor, BindGroupLayout, Device, RenderPipeline, SwapChainDescriptor, BlendFactor, BlendOperation};
 
 use crate::rendering::bidimensional::{
     gl_representations::TexturedGlVertex, scion2d::Renderable2D, transform::Position2D,
@@ -98,8 +96,16 @@ impl Renderable2D for Square {
                 entry_point: "main",
                 targets: &[wgpu::ColorTargetState {
                     format: sc_desc.format,
-                    alpha_blend: wgpu::BlendState::REPLACE,
-                    color_blend: wgpu::BlendState::REPLACE,
+                    alpha_blend: wgpu::BlendState {
+                        src_factor: BlendFactor::One,
+                        dst_factor: BlendFactor::One,
+                        operation: BlendOperation::Add,
+                    },
+                    color_blend: wgpu::BlendState {
+                        src_factor: BlendFactor::SrcAlpha,
+                        dst_factor: BlendFactor::OneMinusSrcAlpha,
+                        operation: BlendOperation::Add,
+                    },
                     write_mask: wgpu::ColorWrite::ALL,
                 }],
             }),

src/rendering/bidimensional/components/triangle.rs

@@ -1,8 +1,6 @@
 use std::ops::Range;
 
-use wgpu::{
-    util::BufferInitDescriptor, BindGroupLayout, Device, RenderPipeline, SwapChainDescriptor,
-};
+use wgpu::{util::BufferInitDescriptor, BindGroupLayout, Device, RenderPipeline, SwapChainDescriptor, BlendFactor, BlendOperation};
 
 use crate::rendering::bidimensional::{
     gl_representations::TexturedGlVertex, scion2d::Renderable2D, transform::Position2D,
@@ -84,8 +82,16 @@ impl Renderable2D for Triangle {
                 entry_point: "main",
                 targets: &[wgpu::ColorTargetState {
                     format: sc_desc.format,
-                    alpha_blend: wgpu::BlendState::REPLACE,
-                    color_blend: wgpu::BlendState::REPLACE,
+                    alpha_blend: wgpu::BlendState {
+                        src_factor: BlendFactor::One,
+                        dst_factor: BlendFactor::One,
+                        operation: BlendOperation::Add,
+                    },
+                    color_blend: wgpu::BlendState {
+                        src_factor: BlendFactor::SrcAlpha,
+                        dst_factor: BlendFactor::OneMinusSrcAlpha,
+                        operation: BlendOperation::Add,
+                    },
                     write_mask: wgpu::ColorWrite::ALL,
                 }],
             }),

src/rendering/bidimensional/scion2d.rs

@@ -216,7 +216,7 @@ fn get_default_color_attachment(frame: &SwapChainTexture) -> RenderPassColorAtta
         resolve_target: None,
         ops: wgpu::Operations {
             load: wgpu::LoadOp::Clear(wgpu::Color {
-                r: 0.,
+                r: 1.,
                 g: 0.,
                 b: 0.,
                 a: 1.0,