From 6f2be8e44b1f1a3f619d9bf4a6bb13f7f35ad687 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Mon, 4 Apr 2022 11:24:21 -0700
Subject: [PATCH] awful text rendering

---
 shaders/text.v.glsl    |  5 +++--
 src/TextRenderer.zig   | 27 ++++++++++++++++++++++-----
 src/opengl/Program.zig |  7 +++++++
 3 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/shaders/text.v.glsl b/shaders/text.v.glsl
index 2d0aba729..2f835dafa 100644
--- a/shaders/text.v.glsl
+++ b/shaders/text.v.glsl
@@ -1,10 +1,11 @@
 #version 330 core
-
 layout (location = 0) in vec4 vertex; // <vec2 pos, vec2 tex>
 out vec2 TexCoords;
 
+uniform mat4 projection;
+
 void main()
 {
-    gl_Position = vec4(vertex.xy, 0.0, 1.0);
+    gl_Position = projection * vec4(vertex.xy, 0.0, 1.0);
     TexCoords = vertex.zw;
 }
diff --git a/src/TextRenderer.zig b/src/TextRenderer.zig
index c55feeaf2..4ea49875a 100644
--- a/src/TextRenderer.zig
+++ b/src/TextRenderer.zig
@@ -12,6 +12,7 @@ chars: CharList,
 vao: gl.VertexArray = undefined,
 vbo: gl.Buffer = undefined,
 program: gl.Program = undefined,
+projection: gb.gbMat4 = undefined,
 
 const CharList = std.ArrayListUnmanaged(Char);
 const Char = struct {
@@ -114,11 +115,7 @@ pub fn init(alloc: std.mem.Allocator) !TextRenderer {
         @embedFile("../shaders/text.f.glsl"),
     );
 
-    // Our project
-    var proj: gb.gbMat4 = undefined;
-    gb.gb_mat4_ortho2d(&proj, 0, 640, 0, 480);
-
-    return TextRenderer{
+    var res = TextRenderer{
         .alloc = alloc,
         .ft = ft,
         .face = face,
@@ -126,7 +123,14 @@ pub fn init(alloc: std.mem.Allocator) !TextRenderer {
         .program = program,
         .vao = vao,
         .vbo = vbo,
+        .projection = undefined,
     };
+
+    // Update the initialize size so we have some projection. We
+    // expect this will get updated almost immediately.
+    try res.setScreenSize(3000, 1666);
+
+    return res;
 }
 
 pub fn deinit(self: *TextRenderer) void {
@@ -141,6 +145,19 @@ pub fn deinit(self: *TextRenderer) void {
     self.* = undefined;
 }
 
+pub fn setScreenSize(self: *TextRenderer, w: i32, h: i32) !void {
+    gb.gb_mat4_ortho2d(
+        &self.projection,
+        0,
+        @intToFloat(f32, w),
+        0,
+        @intToFloat(f32, h),
+    );
+
+    try self.program.use();
+    try self.program.setUniform("projection", self.projection);
+}
+
 pub fn render(
     self: TextRenderer,
     text: []const u8,
diff --git a/src/opengl/Program.zig b/src/opengl/Program.zig
index 1a95dc258..1ad8e0b5d 100644
--- a/src/opengl/Program.zig
+++ b/src/opengl/Program.zig
@@ -4,6 +4,7 @@ const std = @import("std");
 const assert = std.debug.assert;
 const log = std.log.scoped(.opengl);
 
+const gb = @import("../gb_math.zig");
 const c = @import("c.zig");
 const Shader = @import("Shader.zig");
 const errors = @import("errors.zig");
@@ -76,6 +77,12 @@ pub inline fn setUniform(p: Program, n: [:0]const u8, value: anytype) !void {
     switch (@TypeOf(value)) {
         @Vector(3, f32) => c.glUniform3f(loc, value[0], value[1], value[2]),
         @Vector(4, f32) => c.glUniform4f(loc, value[0], value[1], value[2], value[3]),
+        gb.gbMat4 => c.glUniformMatrix4fv(
+            loc,
+            1,
+            c.GL_FALSE,
+            @ptrCast([*c]const f32, &value),
+        ),
         else => unreachable,
     }
     try errors.getError();