From 306e6cca8e49638779b111d66852877416971a59 Mon Sep 17 00:00:00 2001
From: sanine-a <sanine.not@pm.me>
Date: Sun, 29 Nov 2020 22:38:45 -0600
Subject: add camera functions and fix bug in argument parsing

---
 demo/main.lua           |  96 +-------------------------------
 src/glm_bindings.c      |   6 +-
 src/glm_bindings.h      |   8 +++
 src/glm_mat4_bindings.c |  98 +++++++++++++++++++++++++++++++++
 src/honey_lua.c         | 142 ++++++++++++++++++++++--------------------------
 5 files changed, 179 insertions(+), 171 deletions(-)

diff --git a/demo/main.lua b/demo/main.lua
index 660614d..ec5746a 100644
--- a/demo/main.lua
+++ b/demo/main.lua
@@ -1,95 +1,3 @@
-local Vector = require('Vector')
-local Matrix = require('Matrix')
-local FPSCamera = require('FPSCamera')
-local Node = require('Node')
-local SpatialShader = require('SpatialShader')
-local ScreenQuad = require('ScreenQuad')
-local MeshInstance = require('MeshInstance')
-FPSCamera.movement_speed = 5
+local v = honey.glm.vec3()
 
-honey.input.key.bind(honey.input.key.escape, honey.exit)
-
-local buffer = false
-honey.input.key.bind(honey.input.key.f, function(action) if action == 1 then buffer = not buffer end end)
-
-local tex = honey.texture.new()
-honey.texture.load(tex, 'checkerboard.png', false)
-
-local sceneRoot = Node.new(nil,
-                           Vector.Vec3.new(),
-                           Vector.Vec3.new(),
-                           Vector.Vec3.new{1,1,1})
-
-local shader = SpatialShader.new(tex)
-local lightDirection = Vector.Vec3.new{1,1,1}
-lightDirection:normalize()
-shader:setVec3('directional_lights[0].direction', lightDirection)
-shader:setVec3('directional_lights[0].color', Vector.Vec3.new{0,1,0})
-local meshes = honey.mesh.load('Suzanne.obj')
-print(#meshes)
-local suzanne = MeshInstance.new(sceneRoot,
-                                 Vector.Vec3.new{0,0,-3},
-                                 Vector.Vec3.new{0,math.pi,0},
-                                 Vector.Vec3.new{0.5,1,0.5},
-                                 meshes[1],
-                                 shader)
-local plane = MeshInstance.new(suzanne,
-                               Vector.Vec3.new{1,0,0},
-                               Vector.Vec3.new{0,0,0},
-                               Vector.Vec3.new{1,1,1},
-                               honey.primitives.plane(4,4),
-                               shader)
-local plane2 = MeshInstance.new(suzanne,
-                                Vector.Vec3.new{5,0,0},
-                                Vector.Vec3.new{0,math.pi,0},
-                                Vector.Vec3.new{1,1,1},
-                                honey.primitives.plane(4,4),
-                                shader)
-
-suzanne.update = function(self, dt)
-   --local angle = dt * math.pi
-   --self:yaw(angle)
-end
-
-local total_frames = 0
-local total_time = 0
-
-honey.window.set_size(640, 480)
-
-function honey.update(dt)
-   total_time = total_time + dt
-   FPSCamera:update(dt)
-   sceneRoot:updateCascade(dt)
-   if total_time > 1 then
-      print('FPS: '..tostring(total_frames/total_time))
-      total_time = 0
-      total_frames = 0
-   end
-end
-
-function draw_suzanne()
-   sceneRoot:drawCascade(FPSCamera)
-end
-
-function honey.draw()
-   total_frames = total_frames + 1
-
-   if buffer then
-      honey.set_framebuffer(ScreenQuad.fb)
-      honey.set_viewport_size(480,640)
-      honey.clear_color(Vector.Vec4.new().array, true, true, false)
-      honey.enable_depth_test(true)
-      draw_suzanne()
-      
-      honey.set_framebuffer(0)
-      honey.set_viewport_size(640, 480)
-      honey.enable_depth_test(false)
-      honey.clear_color(Vector.Vec4.new{0,0,1,1}.array, true, false, false)
-      ScreenQuad:draw()
-   else
-      honey.clear_color(Vector.Vec4.new{1,1,0,1}.array, true, true, false)
-      honey.set_viewport_size(640, 480)
-      honey.enable_depth_test(true)
-      draw_suzanne()
-   end
-end
+v.dot(v, v)
diff --git a/src/glm_bindings.c b/src/glm_bindings.c
index 41e1d4d..a3ce419 100644
--- a/src/glm_bindings.c
+++ b/src/glm_bindings.c
@@ -87,7 +87,7 @@ void honey_setup_glm(lua_State* L)
     honey_lua_create_table
 	(L, 2,
 
-	 HONEY_TABLE, "__index", 16,
+	 HONEY_TABLE, "__index", 21,
 	 HONEY_FUNCTION, "copy", honey_glm_mat4_copy,
 	 HONEY_FUNCTION, "eye", honey_glm_mat4_eye,
 	 HONEY_FUNCTION, "zero", honey_glm_mat4_zero,
@@ -105,6 +105,10 @@ void honey_setup_glm(lua_State* L)
 	 HONEY_FUNCTION, "rotateY", honey_glm_rotate_y,
 	 HONEY_FUNCTION, "rotateZ", honey_glm_rotate_z,
 	 HONEY_FUNCTION, "rotate", honey_glm_rotate,
+	 HONEY_FUNCTION, "perspective", honey_glm_perspective,
+	 HONEY_FUNCTION, "perspectiveResize", honey_glm_perspective_resize,
+	 HONEY_FUNCTION, "lookAt", honey_glm_lookat,
+	 HONEY_FUNCTION, "look", honey_glm_look,
 
 	 HONEY_FUNCTION, "__gc", honey_glm_array_destroy);
     honey_glm_mat4_mt_ref = luaL_ref(L, LUA_REGISTRYINDEX);
diff --git a/src/glm_bindings.h b/src/glm_bindings.h
index c9eaa91..6c1898f 100644
--- a/src/glm_bindings.h
+++ b/src/glm_bindings.h
@@ -188,4 +188,12 @@ int honey_glm_rotate_z(lua_State* L);
 
 int honey_glm_rotate(lua_State* L);
 
+int honey_glm_perspective(lua_State* L);
+
+int honey_glm_perspective_resize(lua_State* L);
+
+int honey_glm_lookat(lua_State* L);
+
+int honey_glm_look(lua_State* L);
+
 #endif
diff --git a/src/glm_mat4_bindings.c b/src/glm_mat4_bindings.c
index f10f954..460cde2 100644
--- a/src/glm_mat4_bindings.c
+++ b/src/glm_mat4_bindings.c
@@ -397,3 +397,101 @@ int honey_glm_rotate(lua_State* L)
 
     return 0;
 }
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * Camera functions
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+int honey_glm_perspective(lua_State* L)
+{
+    honey_glm_array *self;
+    float fov, aspect, near, far;
+    honey_lua_parse_arguments
+	(L, 1, 5,
+	 HONEY_USERDATA, &self,
+	 HONEY_NUMBER, &fov,  HONEY_NUMBER, &aspect,
+	 HONEY_NUMBER, &near, HONEY_NUMBER, &far);
+
+    glm_perspective(fov, aspect, near, far, self->data);
+    return 0;
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+int honey_glm_perspective_resize(lua_State* L)
+{
+    honey_glm_array *self;
+    float new_aspect;
+    honey_lua_parse_arguments
+	(L, 1, 2, HONEY_USERDATA, &self, HONEY_NUMBER, new_aspect);
+
+    glm_perspective_resize(new_aspect, self->data);
+    return 0;
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+int honey_glm_lookat(lua_State* L)
+{
+    honey_glm_array *self, *eye, *center, *up;
+    honey_lua_parse_arguments
+	(L, 1, 4,
+	 HONEY_USERDATA, &self,
+	 HONEY_USERDATA, &eye,
+	 HONEY_USERDATA, &center,
+	 HONEY_USERDATA, &up);
+
+    if (eye->type != VEC3)
+	honey_lua_throw_error
+	    (L, "eye vector must be of type VEC3 (%d); got %d instead",
+	     VEC3, eye->type);
+
+    if (center->type != VEC3)
+	honey_lua_throw_error
+	    (L, "center vector must be of type VEC3 (%d); got %d instead",
+	     VEC3, center->type);
+
+    if (up->type != VEC3)
+	honey_lua_throw_error
+	    (L, "up vector must be of type VEC3 (%d); got %d instead",
+	     VEC3, up->type);
+
+    glm_lookat(eye->data, center->data, up->data, self->data);
+    return 0;
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+int honey_glm_look(lua_State* L)
+{
+    honey_glm_array *self, *eye, *dir, *up;
+    honey_lua_parse_arguments
+	(L, 1, 4,
+	 HONEY_USERDATA, &self,
+	 HONEY_USERDATA, &eye,
+	 HONEY_USERDATA, &dir,
+	 HONEY_USERDATA, &up);
+
+    if (eye->type != VEC3)
+	honey_lua_throw_error
+	    (L, "eye vector must be of type VEC3 (%d); got %d instead",
+	     VEC3, eye->type);
+
+    if (dir->type != VEC3)
+	honey_lua_throw_error
+	    (L, "direction vector must be of type VEC3 (%d); got %d instead",
+	     VEC3, dir->type);
+
+    if (up->type != VEC3)
+	honey_lua_throw_error
+	    (L, "up vector must be of type VEC3 (%d); got %d instead",
+	     VEC3, up->type);
+
+    glm_look(eye->data, dir->data, up->data, self->data);
+    return 0;
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
diff --git a/src/honey_lua.c b/src/honey_lua.c
index 2469d37..72624be 100644
--- a/src/honey_lua.c
+++ b/src/honey_lua.c
@@ -25,8 +25,7 @@ struct argument_list {
  */
 
 /* string must be able to hold at least 16 characters. */
-static int type_to_string(char* string,
-			  honey_lua_type type);
+static const char* type_to_string(honey_lua_type type);
 
 static bool check_argument(lua_State* L,
 			   honey_lua_type type,
@@ -100,34 +99,6 @@ void honey_lua_throw_error(lua_State* L,
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 
-static void honey_lua_arg_error(lua_State* L,
-                                honey_lua_type type,
-                                int position)
-{
-    char expected_type[16];
-    type_to_string(expected_type, type);
-    
-    char* error_message;
-    honey_result result;
-    char* got_type = (char*) lua_typename(L, lua_type(L, position));
-    result = honey_format_string(&error_message,
-                                 "bad argument in position %d: "
-                                 "expected %s, but got %s instead.",
-                                 position,
-                                 expected_type,
-                                 got_type);
-    if (result != HONEY_OK) {
-        lua_pushstring(L, "error allocating memory for error message :(");
-    }
-    else {
-        lua_pushstring(L, error_message);
-        free(error_message);
-    }
-    lua_error(L);
-}
-
-/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
-
 static bool check_arg_list(lua_State* L,
 			   struct argument_list arg_list)
 {
@@ -141,28 +112,22 @@ static bool check_arg_list(lua_State* L,
 
 /* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
 
-static int arg_list_to_string(char* string,
-			      int start_index,
+static void arg_list_to_string(char** string,
 			      struct argument_list arg_list)
 {
     struct argument_pair* args = arg_list.args;
 
-    string[start_index] = '(';
+    size_t size = sizeof(char) * (18*arg_list.length + 5);
+    *string = malloc(size);
+
+    memcpy(*string, "(", 2);
 
-    int index = start_index + 1;
-    
     for (int i=0; i<arg_list.length; i++) {
-	index += type_to_string(string + index, args[i].type);
-	if (i != arg_list.length - 1) {
-	    string[index + 1] = ',';
-	    string[index + 2] = ' ';
-	    index += 2;
-	}
+	strcat(*string, type_to_string(args[i].type));
+	if (i != arg_list.length-1)
+	    strcat(*string, ", ");
     }
-
-    string[index] = ')';
-
-    return index+1;
+    strcat(*string, ")");
 }
 
 /* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
@@ -176,19 +141,41 @@ static void arg_lists_to_string(char** string,
 	size += 18*arg_lists[i].length + 5;
 
     *string = calloc(size, sizeof(char));
-    int index = 0;
+
+    char* arg_list_string;
 
     for (int i=0; i<n; i++) {
-	index = arg_list_to_string(*string, index, arg_lists[i]);
-	if (i != n) {
-	    *string[index] = '\n';
-	    index++;
-	}
+	arg_list_to_string(&arg_list_string, arg_lists[i]);
+	strcat(*string, arg_list_string);
+	free(arg_list_string);
+	if (i != n-1)
+	    strcat(*string, "\n");
     }
 }
 
 /* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
 
+static void arguments_to_string(lua_State* L, char** string)
+{
+    unsigned int argc = lua_gettop(L);
+
+    size_t size = sizeof(char) * (18*argc + 5);
+    *string = malloc(size);
+
+    memcpy(*string, "(", 2);
+
+    char type_string[16];
+    for (int i=0; i<argc; i++) {
+	int type = lua_type(L, i+1);
+	strncat(*string, lua_typename(L, type), 16*sizeof(char));
+	if (i != argc-1)
+	    strncat(*string, ", ", 4*sizeof(char));
+    }
+    strncat(*string, ")", 4);
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
 static void get_arg_list(lua_State* L,
 			 struct argument_list arg_list)
 {
@@ -218,6 +205,9 @@ int honey_lua_parse_arguments(lua_State* L, unsigned int n, ...)
 	for (int j=0; j<arg_lists[i].length; j++) {
 	    honey_lua_type type = va_arg(args, honey_lua_type);
 	    void* destination = va_arg(args, void*);
+
+	    arg_lists[i].args[j].type = type;
+	    arg_lists[i].args[j].ptr = destination;
 	}
     }
     
@@ -233,7 +223,18 @@ int honey_lua_parse_arguments(lua_State* L, unsigned int n, ...)
     }
 
     if (index == n) {
-	/* no arguments match, throw error */
+	char* arg_lists_str, *argv, *error;
+	arg_lists_to_string(&arg_lists_str, n, arg_lists);
+	arguments_to_string(L, &argv);
+	honey_format_string
+	    (&error,
+	     "expected arguments of the form\n%s\nbut received\n%s",
+	     arg_lists_str, argv);
+	lua_pushstring(L, error);
+	free(arg_lists_str);
+	free(argv);
+	free(error);
+	lua_error(L);
     }
 	
     
@@ -383,57 +384,46 @@ int honey_exit(lua_State* L)
  */
 
 /* string must be able to hold at least 16 characters. */
-static int type_to_string(char* string,
-			  honey_lua_type type)
+static const char* type_to_string(honey_lua_type type)
 {
     switch(type) {
     case HONEY_BOOLEAN:
-	memcpy(string, "boolean", 8);
-	return 7;
+	return "boolean";
 
     case HONEY_INTEGER:
-	memcpy(string, "integer", 8);
-	return 7;
+	return "integer";
 
     case HONEY_NUMBER:
-	memcpy(string, "number", 7);
-	return 6;
+	return "number";
 
     case HONEY_STRING:
-	memcpy(string, "string", 7);
-	return 6;
+	return "string";
 
     case HONEY_FUNCTION:
-	memcpy(string, "function", 9);
-	return 8;
+	return "function";
 
     case HONEY_TABLE:
-	memcpy(string, "table", 6);
-	return 5;
+	return "table";
 
     case HONEY_NIL:
-	memcpy(string, "nil", 4);
-	return 3;
+	return "nil";
 
     case HONEY_USERDATA:
-	memcpy(string, "userdata", 9);
-	return 8;
+	return "userdata";
 
     case HONEY_LIGHTUSERDATA:
-	memcpy(string, "light userdata", 16);
-	return 15;
+	return "light userdata";
 
     case HONEY_ANY:
-	memcpy(string, "any", 4);
-	return 3;
+	return "any";
 
     default:
-	return 0;
+	return "ERROR";
     }
 }
 
 /* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
-
+	
 static bool check_argument(lua_State* L,
 			   honey_lua_type type,
 			   int index)
-- 
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