integrate with SDL2

Author: kwanCCC

CMakeLists.txt

@@ -2,38 +2,38 @@ cmake_minimum_required(VERSION 3.12.2)
 
 project(OpenGL-tutorial)
 
-file(GLOB HEAD_FILES ${PROJECT_SOURCE_DIR}/include/*.h)
-
 set(CMAKE_CXX_FLAGS "-g -Werror -Wall -Wextra")
 set(CMAKE_CXX_FLAGS "-std=c++17")
 set(CMAKE_CXX_FLAGS "-g -pg -O3")
 
-# set(SOURCES
-#     src/tga.cpp
-#     src/main.cpp
-# )
-
-# add_executable(main ${SOURCES})
+SET(SDL_PREFIX "${CMAKE_BINARY_DIR}/thir-part/SDL2")
 
-# target_include_directories(main
-#     PRIVATE
-#     ${PROJECT_SOURCE_DIR}/include
-# )
+include(ExternalProject)
+ExternalProject_Add(SDL
+    SOURCE_DIR ${CMAKE_SOURCE_DIR}/third-part/SDL2-2.0.9
+    CONFIGURE_COMMAND ${CMAKE_SOURCE_DIR}/third-part/SDL2-2.0.9/configure --prefix=${SDL_PREFIX}
+    BUILD_COMMAND make
+)
 
+SET(SDL_LIB_DIR "${SDL_PREFIX}/lib")
+SET(SDL_INT_DIR "${SDL_PREFIX}/include")
+MESSAGE(STATUS "sdl_lib_dir ---- ${SDL_LIB_DIR}")
+SET(SDL_LIB "${SDL_LIB_DIR}/libSDL2-2.0.0.dylib")
 
-add_library(tga_lib STATIC 
+SET(SOURCES
     src/tga.cpp
+    src/main.cpp
 )
 
-target_include_directories(tga_lib
-    PUBLIC 
-    ${PROJECT_SOURCE_DIR}/include
-)
+INCLUDE_DIRECTORIES(include ${sdl_inc_dir})
 
-add_executable(main 
-    src/main.cpp
-)
+ADD_EXECUTABLE(game ${SOURCES})
+
+ADD_DEPENDENCIES(game SDL)
 
-target_link_libraries(main PRIVATE 
-    tga_lib
+TARGET_LINK_LIBRARIES(game ${SDL_LIB})
+
+TARGET_INCLUDE_DIRECTORIES(game
+    PRIVATE
+    ${PROJECT_SOURCE_DIR}/include
 )

include/window.h

@@ -1,3 +1,4 @@
+#include "SDL2/SDL.h"
 #include "tga.h"
 
 const TGAColor white = TGAColor(255, 255, 255, 255);
@@ -7,11 +8,12 @@ void aliased_line();
 
 void anti_aliased_line();
 
+int sdl();
+
 int main(int argc, char** argv) {
-  char* a = "test";
-  aliased_line();
-  anti_aliased_line();
-  return 0;
+  // aliased_line();
+  // anti_aliased_line();
+  return sdl();
 }
 
 void aliased_line() {
@@ -26,4 +28,129 @@ void anti_aliased_line() {
   image.anti_aliasing_line(50.0, 10.0, 60.0, 90.0, red);
   // image.flip_horizontally();
   image.write_tga_file("output_anti_aliased.tga");
+}
+
+// SDL stuff
+SDL_Window* pWindow = 0;
+SDL_Renderer* pRenderer = 0;
+
+// swaps two numbers
+void swap(int* a, int* b) {
+  int temp = *a;
+  *a = *b;
+  *b = temp;
+}
+
+// returns absolute value of number
+float absolute(float x) {
+  if (x < 0)
+    return -x;
+  else
+    return x;
+}
+
+// returns integer part of a floating point number
+int iPartOfNumber(float x) { return (int)x; }
+
+// rounds off a number
+int roundNumber(float x) { return iPartOfNumber(x + 0.5); }
+
+// returns fractional part of a number
+float fPartOfNumber(float x) {
+  if (x > 0)
+    return x - iPartOfNumber(x);
+  else
+    return x - (iPartOfNumber(x) + 1);
+}
+
+// returns 1 - fractional part of number
+float rfPartOfNumber(float x) { return 1 - fPartOfNumber(x); }
+
+// draws a pixel on screen of given brightness
+// 0<=brightness<=1. We can use your own library
+// to draw on screen
+void drawPixel(int x, int y, float brightness) {
+  int c = 255 * brightness;
+  SDL_SetRenderDrawColor(pRenderer, c, c, c, 255);
+  SDL_RenderDrawPoint(pRenderer, x, y);
+}
+
+void drawAALine(int x0, int y0, int x1, int y1) {
+  int steep = absolute(y1 - y0) > absolute(x1 - x0);
+
+  // swap the co-ordinates if slope > 1 or we
+  // draw backwards
+  if (steep) {
+    swap(&x0, &y0);
+    swap(&x1, &y1);
+  }
+  if (x0 > x1) {
+    swap(&x0, &x1);
+    swap(&y0, &y1);
+  }
+
+  // compute the slope
+  float dx = x1 - x0;
+  float dy = y1 - y0;
+  float gradient = dy / dx;
+  if (dx == 0.0) gradient = 1;
+
+  int xpxl1 = x0;
+  int xpxl2 = x1;
+  float intersectY = y0;
+
+  // main loop
+  if (steep) {
+    int x;
+    for (x = xpxl1; x <= xpxl2; x++) {
+      // pixel coverage is determined by fractional
+      // part of y co-ordinate
+      drawPixel(iPartOfNumber(intersectY), x, rfPartOfNumber(intersectY));
+      drawPixel(iPartOfNumber(intersectY) - 1, x, fPartOfNumber(intersectY));
+      intersectY += gradient;
+    }
+  } else {
+    int x;
+    for (x = xpxl1; x <= xpxl2; x++) {
+      // pixel coverage is determined by fractional
+      // part of y co-ordinate
+      drawPixel(x, iPartOfNumber(intersectY), rfPartOfNumber(intersectY));
+      drawPixel(x, iPartOfNumber(intersectY) - 1, fPartOfNumber(intersectY));
+      intersectY += gradient;
+    }
+  }
+}
+
+int sdl() {
+  SDL_Event event;
+
+  // initialize SDL
+  if (SDL_Init(SDL_INIT_EVERYTHING) >= 0) {
+    // if succeeded create our window
+    pWindow =
+        SDL_CreateWindow("Anti-Aliased Line ", SDL_WINDOWPOS_CENTERED,
+                         SDL_WINDOWPOS_CENTERED, 640, 480, SDL_WINDOW_SHOWN);
+
+    // if the window creation succeeded create our renderer
+    if (pWindow != 0) pRenderer = SDL_CreateRenderer(pWindow, -1, 0);
+  } else
+    return 1;  // sdl could not initialize
+
+  while (1) {
+    if (SDL_PollEvent(&event) && event.type == SDL_QUIT) break;
+
+    // Sets background color to white
+    SDL_SetRenderDrawColor(pRenderer, 255, 255, 255, 255);
+    SDL_RenderClear(pRenderer);
+
+    // draws a black AALine
+    drawAALine(80, 200, 550, 150);
+
+    // show the window
+    SDL_RenderPresent(pRenderer);
+  }
+
+  // clean up SDL
+  SDL_Quit();
+  return 0;
 }

src/main.cpp

@@ -5,6 +5,7 @@
 #include <algorithm>
 #include <fstream>
 #include <iostream>
+#include "SDL2/SDL.h"
 
 TGAImage::TGAImage() : data(NULL), width(0), height(0), bytespp(0) {}
 

src/tga.cpp

@@ -0,0 +1,110 @@
+LOCAL_PATH := $(call my-dir)
+
+###########################
+#
+# SDL shared library
+#
+###########################
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := SDL2
+
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+
+LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_INCLUDES)
+
+LOCAL_SRC_FILES := \
+	$(subst $(LOCAL_PATH)/,, \
+	$(wildcard $(LOCAL_PATH)/src/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/audio/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/audio/android/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/audio/dummy/*.c) \
+	$(LOCAL_PATH)/src/atomic/SDL_atomic.c.arm \
+	$(LOCAL_PATH)/src/atomic/SDL_spinlock.c.arm \
+	$(wildcard $(LOCAL_PATH)/src/core/android/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/cpuinfo/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/dynapi/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/events/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/file/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/haptic/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/haptic/android/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/joystick/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/joystick/android/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/joystick/hidapi/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/loadso/dlopen/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/power/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/power/android/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/filesystem/android/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/sensor/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/sensor/android/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/render/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/render/*/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/stdlib/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/thread/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/thread/pthread/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/timer/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/timer/unix/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/video/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/video/android/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/video/yuv2rgb/*.c) \
+	$(wildcard $(LOCAL_PATH)/src/test/*.c))
+
+LOCAL_SHARED_LIBRARIES := hidapi
+
+LOCAL_CFLAGS += -DGL_GLEXT_PROTOTYPES
+LOCAL_LDLIBS := -ldl -lGLESv1_CM -lGLESv2 -llog -landroid
+
+ifeq ($(NDK_DEBUG),1)
+    cmd-strip :=
+endif
+
+include $(BUILD_SHARED_LIBRARY)
+
+###########################
+#
+# SDL static library
+#
+###########################
+
+LOCAL_MODULE := SDL2_static
+
+LOCAL_MODULE_FILENAME := libSDL2
+
+LOCAL_LDLIBS := 
+LOCAL_EXPORT_LDLIBS := -ldl -lGLESv1_CM -lGLESv2 -llog -landroid
+
+include $(BUILD_STATIC_LIBRARY)
+
+###########################
+#
+# SDL main static library
+#
+###########################
+
+include $(CLEAR_VARS)
+
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
+
+LOCAL_MODULE := SDL2_main
+
+LOCAL_MODULE_FILENAME := libSDL2main
+
+include $(BUILD_STATIC_LIBRARY)
+
+###########################
+#
+# hidapi library
+#
+###########################
+
+include $(CLEAR_VARS)
+
+LOCAL_CPPFLAGS += -std=c++11
+
+LOCAL_SRC_FILES := src/hidapi/android/hid.cpp
+
+LOCAL_MODULE := libhidapi
+LOCAL_LDLIBS := -llog
+
+include $(BUILD_SHARED_LIBRARY)

third-part/SDL2-2.0.9.tar.gz

@@ -0,0 +1,16 @@
+
+Bugs are now managed in the SDL bug tracker, here:
+
+    https://bugzilla.libsdl.org/
+
+You may report bugs there, and search to see if a given issue has already
+ been reported, discussed, and maybe even fixed.
+
+
+You may also find help at the SDL forums/mailing list:
+
+    https://discourse.libsdl.org/
+
+Bug reports are welcome here, but we really appreciate if you use Bugzilla, as
+ bugs discussed on the mailing list may be forgotten or missed.
+