From 2c7d78f0d11a3d103536409e6796237d58b30e05 Mon Sep 17 00:00:00 2001
From: gered <gered@blarg.ca>
Date: Sat, 1 Apr 2023 21:37:00 -0400
Subject: [PATCH] add RgbaBitmap triangle blending options

---
 ggdt/src/graphics/bitmap/rgb/triangles.rs | 59 ++++++++++++++++++++++-
 1 file changed, 58 insertions(+), 1 deletion(-)

diff --git a/ggdt/src/graphics/bitmap/rgb/triangles.rs b/ggdt/src/graphics/bitmap/rgb/triangles.rs
index 8fb3bea..6474149 100644
--- a/ggdt/src/graphics/bitmap/rgb/triangles.rs
+++ b/ggdt/src/graphics/bitmap/rgb/triangles.rs
@@ -1,7 +1,7 @@
 use crate::graphics::bitmap::rgb::RgbaBitmap;
 use crate::graphics::bitmap::triangles::{edge_function, per_pixel_triangle_2d};
+use crate::graphics::color::{from_rgb32_normalized, to_rgb32_normalized, BlendFunction};
 use crate::math::vector2::Vector2;
-use crate::prelude::{from_rgb32, from_rgb32_normalized, to_rgb32_normalized};
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum RgbaTriangle2d<'a> {
@@ -9,15 +9,31 @@ pub enum RgbaTriangle2d<'a> {
 		position: [Vector2; 3], //
 		color: u32,
 	},
+	SolidBlended {
+		position: [Vector2; 3], //
+		color: u32,
+		blend: BlendFunction,
+	},
 	SolidMultiColor {
 		position: [Vector2; 3], //
 		color: [u32; 3],
 	},
+	SolidMultiColorBlended {
+		position: [Vector2; 3], //
+		color: [u32; 3],
+		blend: BlendFunction,
+	},
 	SolidTextured {
 		position: [Vector2; 3], //
 		texcoord: [Vector2; 3],
 		bitmap: &'a RgbaBitmap,
 	},
+	SolidTexturedBlended {
+		position: [Vector2; 3], //
+		texcoord: [Vector2; 3],
+		bitmap: &'a RgbaBitmap,
+		blend: BlendFunction,
+	},
 }
 
 impl RgbaBitmap {
@@ -33,6 +49,15 @@ impl RgbaBitmap {
 					|dest_pixels, _w0, _w1, _w2| *dest_pixels = *color,
 				)
 			}
+			SolidBlended { position, color, blend } => {
+				per_pixel_triangle_2d(
+					self, //
+					position[0],
+					position[1],
+					position[2],
+					|dest_pixels, _w0, _w1, _w2| *dest_pixels = blend.blend(*color, *dest_pixels),
+				)
+			}
 			SolidMultiColor { position, color } => {
 				let inverse_area = 1.0 / edge_function(position[0], position[1], position[2]);
 				let (r1, g1, b1) = from_rgb32_normalized(color[0]);
@@ -51,6 +76,24 @@ impl RgbaBitmap {
 					},
 				)
 			}
+			SolidMultiColorBlended { position, color, blend } => {
+				let inverse_area = 1.0 / edge_function(position[0], position[1], position[2]);
+				let (r1, g1, b1) = from_rgb32_normalized(color[0]);
+				let (r2, g2, b2) = from_rgb32_normalized(color[1]);
+				let (r3, g3, b3) = from_rgb32_normalized(color[2]);
+				per_pixel_triangle_2d(
+					self, //
+					position[0],
+					position[1],
+					position[2],
+					|dest_pixels, w0, w1, w2| {
+						let r = (w0 * r1 + w1 * r2 + w2 * r3) * inverse_area;
+						let g = (w0 * g1 + w1 * g2 + w2 * g3) * inverse_area;
+						let b = (w0 * b1 + w1 * b2 + w2 * b3) * inverse_area;
+						*dest_pixels = blend.blend(to_rgb32_normalized(r, g, b), *dest_pixels)
+					},
+				)
+			}
 			SolidTextured { position, texcoord, bitmap } => {
 				let inverse_area = 1.0 / edge_function(position[0], position[1], position[2]);
 				per_pixel_triangle_2d(
@@ -65,6 +108,20 @@ impl RgbaBitmap {
 					},
 				)
 			}
+			SolidTexturedBlended { position, texcoord, bitmap, blend } => {
+				let inverse_area = 1.0 / edge_function(position[0], position[1], position[2]);
+				per_pixel_triangle_2d(
+					self, //
+					position[0],
+					position[1],
+					position[2],
+					|dest_pixels, w0, w1, w2| {
+						let u = (w0 * texcoord[0].x + w1 * texcoord[1].x + w2 * texcoord[2].x) * inverse_area;
+						let v = (w0 * texcoord[0].y + w1 * texcoord[1].y + w2 * texcoord[2].y) * inverse_area;
+						*dest_pixels = blend.blend(bitmap.sample_at(u, v), *dest_pixels);
+					},
+				)
+			}
 		}
 	}
 }