From 38127d9260744241fbb45c4549373d850c3dde39 Mon Sep 17 00:00:00 2001
From: Dominic Masters <dominic@domsplace.com>
Date: Mon, 18 Aug 2025 19:15:37 -0500
Subject: [PATCH] Ortho re-added

---
 cmake/modules/Findcglm.cmake         | 14 ++++++
 src/dusksdl2/CMakeLists.txt          |  2 +
 src/dusksdl2/display/camera/camera.c | 68 ++++++++++++++++++++++++----
 src/dusksdl2/dusksdl2.h              |  4 +-
 4 files changed, 79 insertions(+), 9 deletions(-)
 create mode 100644 cmake/modules/Findcglm.cmake

diff --git a/cmake/modules/Findcglm.cmake b/cmake/modules/Findcglm.cmake
new file mode 100644
index 0000000..b356a13
--- /dev/null
+++ b/cmake/modules/Findcglm.cmake
@@ -0,0 +1,14 @@
+# Copyright (c) 2025 Dominic Masters
+# 
+# This software is released under the MIT License.
+# https://opensource.org/licenses/MIT
+
+include(FetchContent)
+FetchContent_Declare(
+  cglm
+  GIT_REPOSITORY https://github.com/recp/cglm.git
+  GIT_TAG        v0.9.6
+)
+
+FetchContent_MakeAvailable(cglm)
+set(cglm_FOUND ON)
\ No newline at end of file
diff --git a/src/dusksdl2/CMakeLists.txt b/src/dusksdl2/CMakeLists.txt
index 407a27a..c60259c 100644
--- a/src/dusksdl2/CMakeLists.txt
+++ b/src/dusksdl2/CMakeLists.txt
@@ -12,12 +12,14 @@ target_compile_definitions(${DUSK_TARGET_NAME}
 # Libs
 find_package(SDL2 REQUIRED)
 find_package(OpenGL REQUIRED)
+find_package(cglm REQUIRED)
 
 target_link_libraries(${DUSK_TARGET_NAME}
   PUBLIC
     SDL2::SDL2
     OpenGL::GL
     GL
+    cglm
 )
 
 
diff --git a/src/dusksdl2/display/camera/camera.c b/src/dusksdl2/display/camera/camera.c
index c4fb9d4..e52f813 100644
--- a/src/dusksdl2/display/camera/camera.c
+++ b/src/dusksdl2/display/camera/camera.c
@@ -12,13 +12,19 @@
 
 void cameraUIPush(void) {
   glPushMatrix();
+
+  glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
+
   glViewport(0, 0, RENDER_WIDTH, RENDER_HEIGHT);
   glOrtho(
     0.0f, (float_t)RENDER_WIDTH,
     (float_t)RENDER_HEIGHT, 0.0f,
     -1.0f, 1.0f
   );
+
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
 }
 
 void cameraUIPop(void) {
@@ -27,6 +33,8 @@ void cameraUIPop(void) {
 
 void cameraScreenPush(void) {
   glPushMatrix();
+
+  glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
 
   #if RENDER_USE_FRAMEBUFFER
@@ -46,6 +54,9 @@ void cameraScreenPush(void) {
       -1.0f, 1.0f
     );
   #endif
+
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
 }
 
 void cameraScreenPop(void) {
@@ -56,17 +67,58 @@ void cameraOverworldPush(void) {
   glPushMatrix();
   glLoadIdentity();
   glViewport(0, 0, RENDER_WIDTH, RENDER_HEIGHT);
-  glOrtho(
-    0.0f, (float_t)RENDER_WIDTH,
-    (float_t)RENDER_HEIGHT, 0.0f,
-    -1.0f, 1.0f
+
+  glMatrixMode(GL_PROJECTION);
+  glLoadIdentity();
+
+  const float_t fov = glm_rad(75.0f);
+  const float_t camOffset = 12.0f;
+  const float_t aspect = (float_t)RENDER_WIDTH / (float_t)RENDER_HEIGHT;
+  const float_t pixelPerfectOffset = (
+    tanf((glm_rad(180) - fov) / 2.0f) *
+    ((float_t)RENDER_HEIGHT/ 2.0f)
   );
 
-  glTranslatef(
-    -((float_t)OVERWORLD_CAMERA_X) + ((float_t)RENDER_WIDTH / 2.0f),
-    -((float_t)OVERWORLD_CAMERA_Y) + ((float_t)RENDER_HEIGHT / 2.0f),
+  vec3 look = {
+    OVERWORLD_CAMERA_X,
+    OVERWORLD_CAMERA_Y,
     0.0f
-  );
+  };
+  vec3 eye = {
+    look[0],
+    look[1] + camOffset,
+    look[2] + pixelPerfectOffset
+  };
+  vec3 up = { 0.0f, 1.0f, 0.0f };
+
+  mat4 proj;
+  glm_perspective(fov, aspect, 0.1f, 1000.0f, proj);
+  
+  // Flips rendering on the Y axis, so that it is still right-down even in 3D;
+  proj[1][1] = -proj[1][1];
+
+  mat4 view;
+  glm_lookat(eye, look, up, view);
+
+  mat4 pv;
+  glm_mat4_mul(proj, view, pv);
+
+  glLoadMatrixf((const GLfloat*)pv);
+
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
+
+  // glOrtho(
+  //   0.0f, (float_t)RENDER_WIDTH,
+  //   (float_t)RENDER_HEIGHT, 0.0f,
+  //   -1.0f, 1.0f
+  // );
+
+  // glTranslatef(
+  //   -((float_t)OVERWORLD_CAMERA_X) + ((float_t)RENDER_WIDTH / 2.0f),
+  //   -((float_t)OVERWORLD_CAMERA_Y) + ((float_t)RENDER_HEIGHT / 2.0f),
+  //   0.0f
+  // );
 }
 
 void cameraOverworldPop(void) {
diff --git a/src/dusksdl2/dusksdl2.h b/src/dusksdl2/dusksdl2.h
index 318c111..1000059 100644
--- a/src/dusksdl2/dusksdl2.h
+++ b/src/dusksdl2/dusksdl2.h
@@ -11,4 +11,6 @@
 
 #define GL_GLEXT_PROTOTYPES
 #include <GL/gl.h>
-#include <GL/glext.h>
\ No newline at end of file
+#include <GL/glext.h>
+
+#include <cglm/cglm.h>
\ No newline at end of file