run-time window aspect ratio and font resize

Makefile

@@ -20,7 +20,8 @@ OBJS = \
 	src/gl.o \
 	src/opengl.o \
 	src/test.o \
-	src/font.o
+	src/font.o \
+	src/window.o
 
 all: test.so
 

include/font.h

@@ -10,34 +10,44 @@ namespace font {
     int const glyph_height;
   };
 
-  font_desc const ter_6x12 = {
-    .path = "font/terminus_128x64_6x12.data",
-    .texture_width = 128,
-    .texture_height = 64,
-    .glyph_width = 6,
-    .glyph_height = 12,
-  };
-  font_desc const ter_8x16 = {
-    .path = "font/terminus_128x128_8x16.data",
-    .texture_width = 128,
-    .texture_height = 128,
-    .glyph_width = 8,
-    .glyph_height = 16,
-  };
-  font_desc const ter_10x18 = {
-    .path = "font/terminus_256x128_10x18.data",
-    .texture_width = 256,
-    .texture_height = 128,
-    .glyph_width = 10,
-    .glyph_height = 18,
-  };
-  font_desc const ter_12x24 = {
-    .path = "font/terminus_256x128_12x24.data",
-    .texture_width = 256,
-    .texture_height = 128,
-    .glyph_width = 12,
-    .glyph_height = 24,
+  font_desc const terminus[] = {
+    {
+      .path = "font/terminus_128x64_6x12.data",
+      .texture_width = 128,
+      .texture_height = 64,
+      .glyph_width = 6,
+      .glyph_height = 12,
+    },
+    {
+      .path = "font/terminus_128x128_8x16.data",
+      .texture_width = 128,
+      .texture_height = 128,
+      .glyph_width = 8,
+      .glyph_height = 16,
+    },
+    {
+      .path = "font/terminus_256x128_10x18.data",
+      .texture_width = 256,
+      .texture_height = 128,
+      .glyph_width = 10,
+      .glyph_height = 18,
+    },
+    {
+      .path = "font/terminus_256x128_12x24.data",
+      .texture_width = 256,
+      .texture_height = 128,
+      .glyph_width = 12,
+      .glyph_height = 24,
+    },
+    {
+      .path = "font/terminus_256x256_16x32.data",
+      .texture_width = 256,
+      .texture_height = 256,
+      .glyph_width = 16,
+      .glyph_height = 32,
+    },
   };
+  int const terminus_length = (sizeof (terminus)) / (sizeof (font_desc));
 
   struct font {
     font_desc const * desc;
@@ -52,5 +62,7 @@ namespace font {
   void load_element_buffer();
   void load_shader();
   font load_font(font_desc const& desc);
+  void load_fonts(font * const fonts, font_desc const * const descs, int length);
+  int best_font(font_desc const * const descs, int length);
   void draw_string(font const& font, char const * const s, int x, int y);
 }

include/opengl.h

@@ -4,6 +4,9 @@
 extern "C" {
 #endif
 
+extern char const * g_source_path;
+extern int g_source_path_length;
+
 void * read_file(const char * filename, int * out_size);
 
 unsigned int compile_from_files(const char * vertex_path,

include/test.h

@@ -4,7 +4,7 @@
 extern "C" {
 #endif
 
-  void load();
+  void load(const char * source_path);
   void draw_hud();
   void draw();
   void update(float lx, float ly, float rx, float ry, float tl, float tr,

include/window.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+  extern float g_window_width;
+  extern float g_window_height;
+  void update_window(int width, int height);
+
+#ifdef __cplusplus
+}
+#endif

main.lua

@@ -5,15 +5,17 @@ function init()
    joysticks = love.joystick.getJoysticks()
 
    ffi.cdef[[
-void load();
+void load(const char * source_path);
+void update_window(int width, int height);
 void draw();
 void draw_hud();
 void update(float lx, float ly, float rx, float ry, float tl, float tr,
             int up, int down, int left, int right);
 ]]
-   test = ffi.load("./test.so")
-   test.load()
-
+   local source_path = love.filesystem.getSource()
+   test = ffi.load(source_path .. "/test.so")
+   test.load(source_path)
+   print(love.filesystem.getWorkingDirectory())
 end
 
 local update = function(dt)
@@ -52,6 +54,12 @@ function love.run()
          end
       end
 
+      local width
+      local height
+      local flags
+      width, height, flags = love.window.getMode()
+      test.update_window(width, height)
+
       local dt = love.timer.step()
       update(dt)
 

src/font.cpp

@@ -7,6 +7,7 @@
 #include "opengl.h"
 
 #include "font.h"
+#include "window.h"
 
 namespace font {
 
@@ -94,6 +95,38 @@ namespace font {
     };
   }
 
+  static inline int min(int a, int b)
+  {
+    return a < b ? a : b;
+  }
+
+  int best_font(font_desc const * const descs, int length)
+  {
+    int dimension = min(g_window_width, g_window_height);
+    int ideal_height = (16 * dimension) / 1024;
+    //printf("ideal_height: %d\n", ideal_height);
+    int nearest = dimension;
+    int nearest_ix = -1;
+    for (int i = 0; i < length; i++) {
+      font_desc const& desc = descs[i];
+      int distance = abs(desc.glyph_height - ideal_height);
+      if (distance < nearest) {
+        nearest = distance;
+        nearest_ix = i;
+      }
+    }
+    assert(nearest_ix != -1);
+    //printf("selected %d\n", descs[nearest_ix].glyph_height);
+    return nearest_ix;
+  }
+
+  void load_fonts(font * const fonts, font_desc const * const descs, int length)
+  {
+    for (int i = 0; i < length; i++) {
+      fonts[i] = load_font(descs[i]);
+    }
+  }
+
   inline static XMFLOAT2 glyph_coordinate(font const& font, int ord)
   {
     int c = ord - 32;
@@ -110,7 +143,7 @@ namespace font {
     XMMATRIX transform =
       XMMatrixScaling(font.desc->glyph_width, font.desc->glyph_height, 0)
       * XMMatrixTranslation(x, -y, 0)
-      * XMMatrixScaling(2.0f / 1024.0f, 2.0f / 1024.0f, 0)
+      * XMMatrixScaling(2.0f / g_window_width, 2.0f / g_window_height, 0)
       * XMMatrixTranslation(-1, 1, 0);
     XMFLOAT4X4 transformf;
     XMStoreFloat4x4(&transformf, transform);

src/opengl.c

@@ -7,8 +7,30 @@
 #include "glad/gl.h"
 #include "opengl.h"
 
-void * read_file(const char * filename, int * out_size)
+char const * g_source_path = NULL;
+int g_source_path_length = 0;
+
+char const * join_path(char * buf, const char * filename)
 {
+  if (filename[0] == '/')
+    return filename;
+
+  int filename_length = strlen(filename);
+  assert(filename_length + g_source_path_length + 2 < 1024);
+
+  memcpy(buf, g_source_path, g_source_path_length);
+  buf[g_source_path_length] = '/';
+
+  memcpy(&buf[g_source_path_length + 1], filename, filename_length);
+  buf[g_source_path_length + 1 + filename_length] = 0;
+  return buf;
+}
+
+void * read_file(const char * r_filename, int * out_size)
+{
+  char tmp[1024];
+  char const * filename = join_path(tmp, r_filename);
+
   FILE * f = fopen(filename, "rb");
   if (f == NULL) {
     fprintf(stderr, "fopen(%s): %s\n", filename, strerror(errno));

src/test.cpp

@@ -7,6 +7,7 @@
 #include "directxmath/directxmath.h"
 #include "test.h"
 #include "font.h"
+#include "window.h"
 
 #include "data.inc"
 
@@ -249,10 +250,14 @@ struct view_state {
 
 view_state view_state;
 
-font::font ter_8x16 = {};
+font::font * terminus_fonts;
 
-void load()
+void load(const char * source_path)
 {
+  g_source_path_length = strlen(source_path);
+  assert(source_path[g_source_path_length - 1] != '/');
+  g_source_path = source_path;
+
   fprintf(stderr, "getproc %p\n", SDL_GL_GetProcAddress);
   gladLoadGL((GLADloadfunc)SDL_GL_GetProcAddress);
 
@@ -280,7 +285,9 @@ void load()
 
   font::load_element_buffer();
   font::load_shader();
-  ter_8x16 = font::load_font(font::ter_8x16);
+
+  terminus_fonts = (font::font *)malloc((sizeof (font::font)) * font::terminus_length);
+  font::load_fonts(terminus_fonts, font::terminus, font::terminus_length);
 }
 
 float _ry = 0.0;
@@ -314,7 +321,8 @@ static inline int popcount(int x)
   return __builtin_popcount(x);
 }
 
-void asdf(char * const buf, char const * const label, char const * const format, float value)
+template <typename T>
+void labeled_value(char * const buf, char const * const label, char const * const format, T value)
 {
   const int label_length = strlen(label);
   memcpy(buf, label, label_length);
@@ -328,13 +336,20 @@ void draw_hud()
 
   float y = 10.0f;
 
-  asdf(buf, "fov: ", "%.3f", view_state.fov);
-  font::draw_string(ter_8x16, buf, 10, y);
-  y += ter_8x16.desc->glyph_height;
+  int font_ix = font::best_font(font::terminus, font::terminus_length);
+  font::font const& ter_best = terminus_fonts[font_ix];
 
-  asdf(buf, "pitch: ", "%.9f", view_state.pitch);
-  font::draw_string(ter_8x16, buf, 10, y);
-  y += ter_8x16.desc->glyph_height;
+  labeled_value<float>(buf, "fov: ", "%.3f", view_state.fov);
+  font::draw_string(ter_best, buf, 10, y);
+  y += ter_best.desc->glyph_height;
+
+  labeled_value<float>(buf, "pitch: ", "%.9f", view_state.pitch);
+  font::draw_string(ter_best, buf, 10, y);
+  y += ter_best.desc->glyph_height;
+
+  labeled_value<int>(buf, "font_height: ", "%d", ter_best.desc->glyph_height);
+  font::draw_string(ter_best, buf, 10, y);
+  y += ter_best.desc->glyph_height;
 }
 
 void draw()
@@ -343,7 +358,7 @@ void draw()
   XMMATRIX view = XMMatrixLookAtRH(view_state.eye, at, view_state.up);
 
   float fov_angle_y = XMConvertToRadians(45 * view_state.fov);
-  float aspect_ratio = 1.0;
+  float aspect_ratio = g_window_width / g_window_height;
   float near_z = 1.0;
   float far_z = 0.1;
   XMMATRIX projection = XMMatrixPerspectiveFovRH(fov_angle_y, aspect_ratio, near_z, far_z);

src/window.cpp

@@ -0,0 +1,10 @@
+#include "window.h"
+
+float g_window_width = 1;
+float g_window_height = 1;
+
+void update_window(int width, int height)
+{
+  g_window_width = width;
+  g_window_height = height;
+}