Software renderer implementation

CMakeLists.txt

@@ -125,6 +125,7 @@ if(PLATFORM STREQUAL "switch")
     set(ENABLE_LEGACY_GL OFF CACHE BOOL "Enable the legacy OpenGL renderer" FORCE)
 endif()
 option(ENABLE_MODERN_GL "Enable the modern OpenGL renderer" ON)
+option(ENABLE_SW_RENDERER "Enable the software renderer" ON)
 if(NOT ENABLE_WAD14 AND NOT ENABLE_WAD16 AND NOT ENABLE_WAD17)
     message(FATAL_ERROR "You need to build Butterscotch with at least one WAD version enabled!")
 endif()
@@ -143,6 +144,9 @@ endif()
 if(ENABLE_MODERN_GL)
     add_compile_definitions(ENABLE_MODERN_GL)
 endif()
+if(ENABLE_SW_RENDERER)
+    add_compile_definitions(ENABLE_SW_RENDERER)
+endif()
 
 if(PLATFORM STREQUAL "web-meta")
     # Metadata-only build: just the data.win parser and its direct deps. No VM, no runner, no I/O subsystems.
@@ -278,20 +282,27 @@ if(PLATFORM STREQUAL "cli" OR PLATFORM STREQUAL "vita" OR PLATFORM STREQUAL "swi
     # Matches the GitHub Actions container flags (FORTIFY requires building with optimizations enabled!)
     target_compile_options(butterscotch PRIVATE "$<$<CONFIG:Release,RelWithDebInfo>:-U_FORTIFY_SOURCE;-D_FORTIFY_SOURCE=2>")
 
-    if(NOT ENABLE_LEGACY_GL AND NOT ENABLE_MODERN_GL)
+    if(NOT ENABLE_LEGACY_GL AND NOT ENABLE_MODERN_GL AND NOT ENABLE_SW_RENDERER)
         message(FATAL_ERROR "You must enable at least one renderer!")
     endif()
-    file(GLOB GL_SOURCES src/image/*.c src/gl_common/*.c)
+    file(GLOB GL_SOURCES src/image/*.c)
+    if(ENABLE_LEGACY_GL OR ENABLE_MODERN_GL)
+        file(GLOB GL_SOURCES ${GL_SOURCES} src/gl_common/*.c)
+        target_include_directories(butterscotch PRIVATE ${CMAKE_SOURCE_DIR}/src/gl)
+        target_include_directories(butterscotch PRIVATE ${CMAKE_SOURCE_DIR}/src/gl_common)
+    endif()
     if(ENABLE_LEGACY_GL)
         file(GLOB GL_SOURCES ${GL_SOURCES} src/gl_legacy/*.c)
         target_include_directories(butterscotch PRIVATE ${CMAKE_SOURCE_DIR}/src/gl_legacy)
     endif()
     if(ENABLE_MODERN_GL)
         file(GLOB GL_SOURCES ${GL_SOURCES} src/gl/*.c)
     endif()
+    if(ENABLE_SW_RENDERER)
+        file(GLOB GL_SOURCES ${GL_SOURCES} src/sw/*.c)
+        target_include_directories(butterscotch PRIVATE ${CMAKE_SOURCE_DIR}/src/sw)
+    endif()
     target_sources(butterscotch PRIVATE ${GL_SOURCES})
-    target_include_directories(butterscotch PRIVATE ${CMAKE_SOURCE_DIR}/src/gl)
-    target_include_directories(butterscotch PRIVATE ${CMAKE_SOURCE_DIR}/src/gl_common)
     target_include_directories(butterscotch PRIVATE ${CMAKE_SOURCE_DIR}/src/image)
     if (MSVC)
         target_include_directories(butterscotch PRIVATE ${CMAKE_SOURCE_DIR}/compat/getopt)
@@ -328,12 +339,14 @@ if(PLATFORM STREQUAL "cli" OR PLATFORM STREQUAL "vita" OR PLATFORM STREQUAL "swi
 
     set(PLATFORM_LIBRARIES bzip2 stb_ds sha1 stb_vorbis)
     if(NOT PLATFORM STREQUAL "vita" AND NOT PLATFORM STREQUAL "switch")
-        # GLAD
-        add_library(glad STATIC vendor/glad/src/glad.c)
-        target_include_directories(glad PUBLIC vendor/glad/include)
-        target_compile_options(glad PRIVATE -Wno-unused-but-set-variable)
-        set(PLATFORM_LIBRARIES ${PLATFORM_LIBRARIES} glad)
+        if(ENABLE_LEGACY_GL OR ENABLE_MODERN_GL OR BACKEND STREQUAL "glfw3" OR BACKEND STREQUAL "glfw2")
+            # GLAD
+            add_library(glad STATIC vendor/glad/src/glad.c)
+            target_include_directories(glad PUBLIC vendor/glad/include)
+            set(PLATFORM_LIBRARIES ${PLATFORM_LIBRARIES} glad)
+        endif()
     endif()
+
     if(NOT MSVC)
         set(PLATFORM_LIBRARIES ${PLATFORM_LIBRARIES} m)
     endif()

Makefile

@@ -92,6 +92,9 @@ SYSCFLAGS += $(GLFW3_CFLAGS)
 LIBS += $(GLFW3_LIBS)
 DEFINES += $(DEFINE)USE_GLFW3
 ENABLE_GLAD := 1
+ifdef ENABLE_GLES
+DISABLE_SW_RENDERER := 1
+endif
 endif
 ifeq ($(BACKEND),glfw2)
 GLFW2_CFLAGS := $(shell $(PKG_CONFIG) $(PKG_CONFIG_FLAGS) --cflags libglfw)
@@ -100,6 +103,9 @@ SYSCFLAGS += $(GLFW2_CFLAGS)
 LIBS += $(GLFW2_LIBS)
 DEFINES += $(DEFINE)USE_GLFW2
 ENABLE_GLAD := 1
+ifdef ENABLE_GLES
+DISABLE_SW_RENDERER := 1
+endif
 endif
 ifeq ($(BACKEND),sdl1)
 SDL1_CFLAGS := $(shell $(PKG_CONFIG) $(PKG_CONFIG_FLAGS) --cflags sdl)
@@ -156,6 +162,13 @@ SRCS += $(wildcard src/gl/*.c)
 HEADERS += $(wildcard src/gl/*.h)
 endif
 
+ifndef DISABLE_SW_RENDERER
+DEFINES += -DENABLE_SW_RENDERER
+SRCS += $(wildcard src/sw/*.c)
+HEADERS += $(wildcard src/sw/*.h)
+INCLUDES += -Isrc/sw
+endif
+
 ifdef DISABLE_WAD14
 ifdef DISABLE_WAD16
 ifdef DISABLE_WAD17
@@ -166,9 +179,11 @@ endif
 
 ifdef DISABLE_LEGACY_GL
 ifdef DISABLE_MODERN_GL
+ifdef DISABLE_SW_RENDERER
 $(error must enable at least 1 renderer)
 endif
 endif
+endif
 
 ifeq ($(AUDIO_BACKEND),miniaudio)
 INCLUDES += $(INCLUDE)src/audio/miniaudio $(INCLUDE)vendor/miniaudio

src/backends/appkit.m

@@ -707,3 +707,15 @@ void platformSleepUntil(uint64_t time) {
         YIELD();
     }
 }
+
+#ifdef ENABLE_SW_RENDERER
+
+void platformSetNextFramebuffer(uint32_t* framebuffer, int width, int height)
+{
+    // TODO: this is a placeholder
+    (void) framebuffer;
+    (void) width;
+    (void) height;
+}
+
+#endif

src/backends/glfw2.c

@@ -256,7 +256,7 @@ void platformInitFunctions(Runner *runner) {
 static uint32_t* nextFb = NULL;
 static int fbWidth = 0, fbHeight = 0;
 
-void Runner_setNextFrame(uint32_t* framebuffer, int width, int height) {
+void platformSetNextFramebuffer(uint32_t* framebuffer, int width, int height) {
     nextFb = framebuffer;
     fbWidth = width;
     fbHeight = height;

src/backends/glfw3.c

@@ -329,7 +329,7 @@ void platformInitFunctions(Runner *runner) {
 static uint32_t* nextFb = NULL;
 static int fbWidth = 0, fbHeight = 0;
 
-void Runner_setNextFrame(uint32_t* framebuffer, int width, int height) {
+void platformSetNextFramebuffer(uint32_t* framebuffer, int width, int height) {
     nextFb = framebuffer;
     fbWidth = width;
     fbHeight = height;

src/backends/sdl1.c

@@ -317,7 +317,7 @@ void platformInitFunctions(Runner *runner) {
 
 static SDL_Surface* nextFb = NULL;
 
-void Runner_setNextFrame(uint32_t* framebuffer, int width, int height) {
+void platformSetNextFramebuffer(uint32_t* framebuffer, int width, int height) {
     if (nextFb) {
         SDL_FreeSurface(nextFb);
         nextFb = NULL;
@@ -378,10 +378,10 @@ static int32_t SDLKeyToGml(int sdlkey) {
         case SDLK_RCTRL:     return VK_CONTROL;
         case SDLK_LALT:
         case SDLK_RALT:      return VK_ALT;
-        case SDLK_UP:        return VK_UP;
-        case SDLK_DOWN:      return VK_DOWN;
-        case SDLK_LEFT:      return VK_LEFT;
-        case SDLK_RIGHT:     return VK_RIGHT;
+case SDLK_KP8:        case SDLK_UP:        return VK_UP;
+case SDLK_KP5:case SDLK_KP2:        case SDLK_DOWN:      return VK_DOWN;
+case SDLK_KP4:        case SDLK_LEFT:      return VK_LEFT;
+case SDLK_KP6:        case SDLK_RIGHT:     return VK_RIGHT;
         case SDLK_F1:        return VK_F1;
         case SDLK_F2:        return VK_F2;
         case SDLK_F3:        return VK_F3;

src/backends/sdl2.c

@@ -291,7 +291,7 @@ void platformInitFunctions(Runner *runner) {
 
 static SDL_Surface* nextFb = NULL;
 
-void Runner_setNextFrame(uint32_t* framebuffer, int width, int height) {
+void platformSetNextFramebuffer(uint32_t* framebuffer, int width, int height) {
     if (nextFb) {
         SDL_FreeSurface(nextFb);
         nextFb = NULL;

src/backends/sdl3.c

@@ -237,7 +237,7 @@ void platformInitFunctions(Runner *runner) {
 
 static SDL_Surface* nextFb = NULL;
 
-void Runner_setNextFrame(uint32_t* framebuffer, int width, int height) {
+void platformSetNextFramebuffer(uint32_t* framebuffer, int width, int height) {
     if (nextFb) {
         SDL_DestroySurface(nextFb);
         nextFb = NULL;

src/sw/defines.h

@@ -0,0 +1,39 @@
+#ifndef _SW_DEFINES_H
+#define _SW_DEFINES_H
+
+#include "common.h"
+
+// CONFIG: Change the size of a pixel.
+//
+// 32-bit: 0xAARRGGBB
+// 16-bit: 0b0RRRRRGGGGGBBBBB
+// 8-bit:  0bBBGGGRRR
+#define PIXEL_SIZE 32
+//#define PIXEL_SIZE 16
+//#define PIXEL_SIZE 8
+
+#if defined(__GNUC__) && (__GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96))
+#define LIKELY(cond)   __builtin_expect(!!(cond), 1)
+#define UNLIKELY(cond) __builtin_expect(!!(cond), 0)
+#else
+#define LIKELY(cond) (cond)
+#define UNLIKELY(cond) (cond)
+#endif
+
+#if defined(__GNUC__) || defined(__clang__)
+#define FORCE_INLINE static inline __attribute__((always_inline))
+#elif defined(_MSC_VER) && _MSC_VER >= 1200
+#define FORCE_INLINE static __forceinline
+#else
+#define FORCE_INLINE static inline
+#endif
+
+#if defined(__cplusplus) && __cplusplus >= 201703L
+#define UNUSED [[maybe_unused]]
+#elif defined(__GNUC__) || defined(__clang__)
+#define UNUSED __attribute__ ((unused))
+#else
+#define UNUSED
+#endif
+
+#endif//_SW_DEFINES_H

src/sw/pixel_convert.h

@@ -0,0 +1,103 @@
+#ifndef _PIXEL_CONVERT_H
+#define _PIXEL_CONVERT_H
+
+#include "defines.h"
+#include "binary_utils.h"
+
+#if PIXEL_SIZE == 32
+typedef uint32_t uintpixel_t;
+#elif PIXEL_SIZE == 16
+typedef uint16_t uintpixel_t;
+#elif PIXEL_SIZE == 8
+typedef uint8_t uintpixel_t;
+#define PXL_TRANSPARENT (0xAA)
+#else
+#error "Unknown pixel size!"
+#endif
+
+// The native format coming out of GameMaker Studio's assets.
+typedef union
+{
+	struct {
+		uint8_t r, g, b, a;
+	} p;
+	uint32_t l;
+}
+Pixel32ABGR;
+
+// This is the format the renderer knows how to work with.
+typedef union
+{
+	struct {
+#ifdef IS_BIG_ENDIAN
+		uint8_t a, r, g, b;
+#else
+		uint8_t b, g, r, a;
+#endif
+	} p;
+	uint32_t l;
+}
+Pixel32ARGB;
+
+FORCE_INLINE UNUSED
+uint16_t abgr8888_to_rgb1555(uint32_t xl)
+{
+	Pixel32ABGR x;
+	x.l = xl;
+	return (x.p.b >> 3) | ((x.p.g >> 3) << 5) | ((x.p.r >> 3) << 10) | ((x.p.a >> 7) << 15);
+}
+
+FORCE_INLINE UNUSED
+uint8_t abgr8888_to_rgb332(uint32_t xl)
+{
+	Pixel32ABGR x;
+	x.l = xl;
+
+#if PIXEL_SIZE == 8
+	//check if transparent
+	if (x.p.a < 128)
+		return PXL_TRANSPARENT;
+#endif
+
+	uint8_t pxl = (x.p.r >> 5) | ((x.p.g >> 5) << 3) | ((x.p.b >> 6) << 6);
+
+#if PIXEL_SIZE == 8
+	//hacky fixup
+	if (pxl == PXL_TRANSPARENT)
+		pxl++;
+#endif
+
+	return pxl;
+}
+
+FORCE_INLINE UNUSED
+uintpixel_t swrConvertPixelBase(uint32_t gmPixel)
+{
+#if PIXEL_SIZE == 32
+	return (gmPixel & 0xFF00FF00) | ((gmPixel & 0xFF) << 16) | ((gmPixel >> 16) & 0xFF);
+#elif PIXEL_SIZE == 16
+	return abgr8888_to_rgb1555(gmPixel);
+#elif PIXEL_SIZE == 8
+	return abgr8888_to_rgb332(gmPixel);
+#endif
+}
+
+#if PIXEL_SIZE == 32
+#define TRANSPARENT_MASK 0xFF000000
+#elif PIXEL_SIZE == 16
+#define TRANSPARENT_MASK 0x8000
+#endif
+
+#if defined IS_BIG_ENDIAN
+
+#define swrConvertPixel(x)        swrConvertPixelBase(x | 0xFF000000)
+#define swrConvertPixelTexture(x) swrConvertPixelBase(BinaryUtils_bswap32(x))
+
+#else
+
+#define swrConvertPixel(x)        swrConvertPixelBase((x) | 0xFF000000)
+#define swrConvertPixelTexture(x) swrConvertPixelBase(x)
+
+#endif
+
+#endif//_PIXEL_CONVERT_H