getting text rendering working with stb_truetype

assets/shaders/text.fragment.glsl

@@ -0,0 +1,11 @@
+#version 330 core
+out vec4 pixel_color;
+
+in vec4 frag_color;
+in vec2 frag_uv_position;
+
+uniform sampler2D glyph_atlas;
+
+void main() {
+    pixel_color = vec4(1,1,1,texture(glyph_atlas, frag_uv_position).r);
+};

assets/shaders/text.vertex.glsl

@@ -0,0 +1,73 @@
+#version 330 core
+layout (location = 0) in vec2 begin;
+layout (location = 1) in int glyph;
+layout (location = 2) in float lineHeight;
+layout (location = 3) in vec4 color;
+
+/*
+typedef struct GlyphMeta GlyphMeta;
+struct GlyphMeta {
+    // chunk 1
+    RLVector2 uv0;
+    RLVector2 uv1;
+
+    // chunk 2
+    real32 xOffset;
+    real32 yOffset;
+    real32 width;
+    real32 height;
+};
+*/
+
+uniform samplerBuffer glyph_table;
+
+uniform mat4 projection;
+uniform sampler2D font;
+
+out vec4 frag_color;
+out vec2 frag_uv_position;
+
+const vec2 rectangle_vertices[4] = vec2[](
+    vec2(-1, -1), // bl
+    vec2(-1,  1), // tl
+    vec2( 1, -1), // br
+    vec2( 1,  1) // tr
+);
+
+const vec2 uv0_vertices[4] = vec2[](
+    vec2(1, 0), // bl
+    vec2(1, 1), // tl
+    vec2(0, 0), // br
+    vec2(0, 1) // tr
+);
+
+const vec2 uv1_vertices[4] = vec2[](
+    vec2(0, 1),
+    vec2(0, 0),
+    vec2(1, 1),
+    vec2(1, 0)
+);
+
+void main() {
+    vec4 chunk1 = texelFetch(glyph_table, glyph * 2 + 0);
+    vec4 chunk2 = texelFetch(glyph_table, glyph * 2 + 1);
+
+    vec2 uv0 = chunk1.xy;
+    vec2 uv1 = chunk1.zw;
+    vec2 offset = chunk2.xy;
+    vec2 dims = chunk2.zw;
+
+    vec2 p0 = begin + offset*lineHeight;
+    vec2 p1 = begin + (offset + dims)*lineHeight;
+
+    vec2 dest_half_size = (p1 - p0) / 2;
+    vec2 dest_center = (p1 + p0) / 2;
+    vec2 dest_position = rectangle_vertices[gl_VertexID] * dest_half_size + dest_center;
+
+    vec2 uv_position = uv0 * uv0_vertices[gl_VertexID] + uv1 * uv1_vertices[gl_VertexID];
+
+    gl_Position = projection * vec4(dest_position, 0, 1);
+
+    frag_color = color;
+    frag_uv_position = vec2(uv_position.x, uv_position.y);
+}