From e7b8d8f66336986d314337c9a780b783f69266ba Mon Sep 17 00:00:00 2001
From: Albert Vaca Cintora <albertvaka@gmail.com>
Date: Sat, 17 Oct 2020 14:33:46 +0200
Subject: [PATCH] Add camera demo

---
 demos/CMakeLists.txt |  7 +++-
 demos/camera/main.c  | 98 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 104 insertions(+), 1 deletion(-)
 create mode 100644 demos/camera/main.c

diff --git a/demos/CMakeLists.txt b/demos/CMakeLists.txt
index ae29ffae..cc1c6bb8 100644
--- a/demos/CMakeLists.txt
+++ b/demos/CMakeLists.txt
@@ -10,6 +10,9 @@ endif(MINGW)
 add_executable(init-demo init/main.c)
 target_link_libraries (init-demo ${DEMO_LIBS})
 
+add_executable(camera-demo camera/main.c)
+target_link_libraries (camera-demo ${DEMO_LIBS})
+
 add_executable(3d-demo 3d/main.c ../src/externals/glew/glew.c)
 target_link_libraries (3d-demo ${DEMO_LIBS})
 
@@ -17,4 +20,6 @@ add_executable(tutorial-space-demo tutorial-space/main.c)
 target_link_libraries (tutorial-space-demo ${DEMO_LIBS})
 
 add_executable(simple-shader-demo simple-shader/main.c)
-target_link_libraries (simple-shader-demo ${DEMO_LIBS})
\ No newline at end of file
+target_link_libraries (simple-shader-demo ${DEMO_LIBS})
+
+file(COPY data DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
\ No newline at end of file
diff --git a/demos/camera/main.c b/demos/camera/main.c
new file mode 100644
index 00000000..6ec30979
--- /dev/null
+++ b/demos/camera/main.c
@@ -0,0 +1,98 @@
+#include <SDL.h>
+#include "SDL_gpu.h"
+
+#define MOVE_VEL 800
+#define ZOOM_VEL 2
+#define ROTATE_VEL 45
+
+void main_loop(GPU_Target* screen)
+{
+    Uint8 done;
+    SDL_Event event;
+    Uint32 start_time, end_time;
+    float dt;
+    GPU_Camera camera;
+    GPU_Image *image1, *image2;
+
+    image1 = GPU_LoadImage("data/test3.png");
+    image2 = GPU_LoadImage("data/test2.png");
+
+    camera = GPU_GetDefaultCamera();
+
+    start_time = SDL_GetTicks();
+    dt = 0.0f;
+
+    done = 0;
+    while(!done)
+    {
+        while(SDL_PollEvent(&event))
+        {
+            if(event.type == SDL_QUIT)
+                done = 1;
+            else if(event.type == SDL_KEYDOWN)
+            {
+                if(event.key.keysym.sym == SDLK_ESCAPE)
+                    done = 1;
+                else if(event.key.keysym.sym == SDLK_c)
+                    camera.use_centered_origin = !camera.use_centered_origin;
+                else if(event.key.keysym.sym == SDLK_w)
+                    camera.y -= MOVE_VEL*dt;
+                else if(event.key.keysym.sym == SDLK_s)
+                    camera.y += MOVE_VEL*dt;
+                else if(event.key.keysym.sym == SDLK_a)
+                    camera.x -= MOVE_VEL*dt;
+                else if(event.key.keysym.sym == SDLK_d)
+                    camera.x += MOVE_VEL*dt;
+                else if(event.key.keysym.sym == SDLK_d)
+                    camera.x += MOVE_VEL*dt;
+                else if(event.key.keysym.sym == SDLK_r)
+                    camera.zoom_x = camera.zoom_y += ZOOM_VEL*dt;
+                else if(event.key.keysym.sym == SDLK_f)
+                    camera.zoom_x = camera.zoom_y -= ZOOM_VEL*dt;
+                else if(event.key.keysym.sym == SDLK_q)
+                    camera.angle -= ROTATE_VEL*dt;
+                else if(event.key.keysym.sym == SDLK_e)
+                    camera.angle += ROTATE_VEL*dt;
+            }
+        }
+
+        GPU_SetCamera(screen, &camera);
+
+        GPU_Clear(screen);
+
+        for (int i = -10; i < 10; i++) {
+            GPU_BlitScale(image2, NULL, screen, i*128, 0, 0.5f, 0.5f);
+            GPU_BlitScale(image2, NULL, screen, 0, i*128, 0.5f, 0.5f);
+            GPU_BlitScale(image1, NULL, screen, i*100, i*100, 0.5f, 0.5f);
+            GPU_BlitScale(image1, NULL, screen, i*100, -i*100, 0.5f, 0.5f);
+        }
+
+        GPU_Flip(screen);
+
+        SDL_Delay(10);
+        end_time = SDL_GetTicks();
+        dt = (end_time - start_time)/1000.0f;
+        start_time = end_time;
+    }
+}
+
+int main(int argc, char* argv[])
+{
+    GPU_Target* screen;
+
+    GPU_SetDebugLevel(GPU_DEBUG_LEVEL_1);
+
+    screen = GPU_Init(800, 600, GPU_DEFAULT_INIT_FLAGS);
+    if(screen == NULL)
+        return -1;
+
+    GPU_EnableCamera(screen, true);
+
+    main_loop(screen);
+
+    GPU_Quit();
+
+    return 0;
+}
+
+