From 1c4edfbcd1c5a17a8b802707479332f730f24eb3 Mon Sep 17 00:00:00 2001
From: _ <>
Date: Sun, 15 Mar 2020 18:44:05 +0000
Subject: [PATCH] Text rendering works, though it's still ugly

---
 src/bin/pumpkin.rs | 76 ++++++++++++++++++++++++++++++++--------------
 1 file changed, 54 insertions(+), 22 deletions(-)

diff --git a/src/bin/pumpkin.rs b/src/bin/pumpkin.rs
index 2b38c2a..b481d1a 100644
--- a/src/bin/pumpkin.rs
+++ b/src/bin/pumpkin.rs
@@ -561,7 +561,7 @@ impl GameGraphics {
 		
 		let texture_sky = Texture::from_file ("sky.png");
 		let texture_grass = Texture::from_file ("grass.png");
-		let texture_font = Texture::from_file ("checkerboard.png");
+		let texture_font = Texture::from_file ("font.png");
 		
 		let (pitch_colors, grass_index) = {
 			let silver = (255.0, 255.0, 255.0);
@@ -818,7 +818,7 @@ impl GameGraphics {
 				];
 				
 				let v: Vec <u32> = (0u32..1024).map (|i| {
-					quad.iter ().map (move |j| 6 * i + j)
+					quad.iter ().map (move |j| 4 * i + j)
 				}).flatten ().collect ();
 				gpu_buffers::IndexBuffer::from_slice_u32 (&v)
 			}
@@ -1119,11 +1119,46 @@ impl GameGraphics {
 			Mat4::from_scale ((2.0 / screen_size.0, 2.0 / screen_size.1, 1.0).into ());
 			glezz::uniform_matrix_4fv (unis [&MVP], &mvp);
 			
+			let stride_floats = 3 + 2;
+			let stride_bytes = stride_floats * 4;
+			
+			let mut vert_buffer = Vec::with_capacity (stride_floats * 1024);
+			
+			// X and Y are in screen pixels, c is ASCII
+			let mut add_char = |x: f32, y: f32, c: char| {
+				let c = c as u32 - 1;
+				
+				assert! (c >= 0);
+				assert! (c < 128);
+				
+				let u = (c % 32) as f32;
+				let v = (c / 32) as f32;
+				
+				for vert in &[
+					(0.0, 0.0),
+					(1.0, 0.0),
+					(1.0, 1.0),
+					(0.0, 1.0),
+				] {
+					vert_buffer.push (x + vert.0 * 8.0);
+					vert_buffer.push (y + vert.1 * 18.0);
+					
+					vert_buffer.push ((u + vert.0) * 8.0 / 256.0);
+					vert_buffer.push ((v + 1.0 - vert.1) * 18.0 / 256.0);
+				}
+			};
+			
+			let s = "Pumpkin";
+			
+			for (i, c) in s.chars ().enumerate () {
+				add_char (30.0 + i as f32 * 8.0, 30.0, c);
+			}
+			
 			let pos: Vec <f32> = vec! [
-				0.0, 0.0, 0.0,
-				256.0, 0.0, 0.0,
-				256.0, 256.0, 0.0,
-				0.0, 256.0, 0.0,
+				0.0, 0.0,
+				256.0, 0.0,
+				256.0, 256.0,
+				0.0, 256.0,
 			];
 			
 			use std::convert::TryInto;
@@ -1144,24 +1179,21 @@ impl GameGraphics {
 				use renderable_model::attributes::*;
 				use std::ffi::c_void;
 				
-				gl::BufferSubData (
-					gl::ARRAY_BUFFER,
-					0.try_into ().unwrap (),
-					(4 * 4 * 3).try_into ().unwrap (),
-					&pos [0] as *const f32 as *const c_void
-				);
+				if true {
+					gl::BufferSubData (
+						gl::ARRAY_BUFFER,
+						0.try_into ().unwrap (),
+						(s.len () * 4 * 4 * 4).try_into ().unwrap (),
+						&vert_buffer [0] as *const f32 as *const c_void
+					);
+					
+					gl::VertexAttribPointer (attrs [POS].unwrap (), 2, gl::FLOAT, 0u8, 4 * 4, 0 as *const f32 as *const c_void);
+					gl::VertexAttribPointer (attrs [UV].unwrap (), 2, gl::FLOAT, 0u8, 4 * 4, (4 * 2) as *const f32 as *const c_void);
+				}
 				
-				gl::BufferSubData (
-					gl::ARRAY_BUFFER,
-					(4 * 4 * 3).try_into ().unwrap (),
-					(4 * 4 * 2).try_into ().unwrap (),
-					&uv [0] as *const f32 as *const c_void
-				);
+				let num_indices = s.len () as u32 * 6;
 				
-				gl::VertexAttribPointer (attrs [POS].unwrap (), 3, gl::FLOAT, 0u8, 4 * 3, 0 as *const f32 as *const c_void);
-				gl::VertexAttribPointer (attrs [UV].unwrap (), 2, gl::FLOAT, 0u8, 4 * 2, (4 * 4 * 3) as *const f32 as *const c_void);
-				
-				gl::DrawRangeElements (gl::TRIANGLES, 0, 6, 6, gl::UNSIGNED_INT, 0 as *const u32 as *const c_void);
+				gl::DrawRangeElements (gl::TRIANGLES, 0, num_indices, num_indices as i32, gl::UNSIGNED_INT, 0 as *const u32 as *const c_void);
 			}
 		});
 		}