Simple VRAM Allocator

examples/cube/src/main.rs

@@ -9,7 +9,7 @@ use psp::sys::{
     FrontFaceDirection, ShadingModel, GuState, TexturePixelFormat, DepthFunc,
     VertexType, ClearBuffer, MipmapLevel,
 };
-use psp::gu_utils::get_static_vram_buffer;
+use psp::vram_alloc::SimpleVramAllocator;
 use psp::{BUF_WIDTH, SCREEN_WIDTH, SCREEN_HEIGHT};
 
 psp::module!("sample_cube", 1, 1);
@@ -88,18 +88,19 @@ fn psp_main() {
 unsafe fn psp_main_inner() {
     psp::enable_home_button();
 
-    let fbp0 = get_static_vram_buffer(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm8888);
-    let fbp1 = get_static_vram_buffer(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm8888);
-    let zbp = get_static_vram_buffer(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm4444);
+    let mut allocator = SimpleVramAllocator::new();
+    let fbp0 = allocator.alloc_texture_pixels(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm8888).start();
+    let fbp1 = allocator.alloc_texture_pixels(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm8888).start();
+    let zbp = allocator.alloc_texture_pixels(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm4444).start();
 
     sys::sceGumLoadIdentity();
 
     sys::sceGuInit();
 
     sys::sceGuStart(GuContextType::Direct, &mut LIST.0 as *mut [u32; 0x40000] as *mut _);
-    sys::sceGuDrawBuffer(DisplayPixelFormat::Psm8888, fbp0, BUF_WIDTH as i32);
-    sys::sceGuDispBuffer(SCREEN_WIDTH as i32, SCREEN_HEIGHT as i32, fbp1, BUF_WIDTH as i32);
-    sys::sceGuDepthBuffer(zbp, BUF_WIDTH as i32);
+    sys::sceGuDrawBuffer(DisplayPixelFormat::Psm8888, fbp0 as _, BUF_WIDTH as i32);
+    sys::sceGuDispBuffer(SCREEN_WIDTH as i32, SCREEN_HEIGHT as i32, fbp1 as _, BUF_WIDTH as i32);
+    sys::sceGuDepthBuffer(zbp as _, BUF_WIDTH as i32);
     sys::sceGuOffset(2048 - (SCREEN_WIDTH / 2), 2048 - (SCREEN_HEIGHT / 2));
     sys::sceGuViewport(2048, 2048, SCREEN_WIDTH as i32, SCREEN_HEIGHT as i32);
     sys::sceGuDepthRange(65535, 0);

examples/gu-background/src/main.rs

@@ -5,7 +5,7 @@
 
 use core::ffi::c_void;
 use psp::sys::{self, GuState, TexturePixelFormat, DisplayPixelFormat};
-use psp::gu_utils::get_static_vram_buffer;
+use psp::vram_alloc::SimpleVramAllocator;
 use psp::{BUF_WIDTH, SCREEN_WIDTH, SCREEN_HEIGHT};
 
 psp::module!("sample_gu_background", 1, 1);
@@ -15,19 +15,21 @@ static mut LIST: psp::Align16<[u32; 0x40000]> = psp::Align16([0; 0x40000]);
 fn psp_main() {
     psp::enable_home_button();
 
+    let mut allocator = SimpleVramAllocator::new();
+    let fbp0 = allocator.alloc_texture_pixels(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm8888).start();
+    let fbp1 = allocator.alloc_texture_pixels(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm8888).start();
+    let zbp = allocator.alloc_texture_pixels(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm4444).start();
+
     unsafe {
-        let fbp0 = get_static_vram_buffer(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm8888);
-        let fbp1 = get_static_vram_buffer(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm8888);
-        let zbp = get_static_vram_buffer(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm4444);
 
         sys::sceGuInit();
         sys::sceGuStart(
             sys::GuContextType::Direct,
             &mut LIST as *mut _ as *mut c_void,
         );
-        sys::sceGuDrawBuffer(DisplayPixelFormat::Psm8888, fbp0, BUF_WIDTH as i32);
-        sys::sceGuDispBuffer(SCREEN_WIDTH as i32, SCREEN_HEIGHT as i32, fbp1, BUF_WIDTH as i32);
-        sys::sceGuDepthBuffer(zbp, BUF_WIDTH as i32);
+        sys::sceGuDrawBuffer(DisplayPixelFormat::Psm8888, fbp0 as _, BUF_WIDTH as i32);
+        sys::sceGuDispBuffer(SCREEN_WIDTH as i32, SCREEN_HEIGHT as i32, fbp1 as _, BUF_WIDTH as i32);
+        sys::sceGuDepthBuffer(zbp as _, BUF_WIDTH as i32);
         sys::sceGuOffset(2048 - (SCREEN_WIDTH/2), 2048 - (SCREEN_HEIGHT/2));
         sys::sceGuViewport(2048, 2048, SCREEN_WIDTH as i32, SCREEN_HEIGHT as i32);
         sys::sceGuDepthRange(65535, 0);

examples/gu-debug-print/src/main.rs

@@ -6,7 +6,7 @@
 
 use core::ffi::c_void;
 use psp::sys::{self, TexturePixelFormat, DisplayPixelFormat};
-use psp::gu_utils::get_static_vram_buffer;
+use psp::vram_alloc::SimpleVramAllocator;
 use psp::{BUF_WIDTH, SCREEN_HEIGHT};
 
 psp::module!("sample_gu_debug", 1, 1);
@@ -16,14 +16,16 @@ static mut LIST: psp::Align16<[u32; 0x40000]> = psp::Align16([0; 0x40000]);
 fn psp_main() {
     psp::enable_home_button();
 
+    let mut allocator = SimpleVramAllocator::new();
+    let fbp0 = allocator.alloc_texture_pixels(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm8888).start();
+
     unsafe {
-        let fbp0 = get_static_vram_buffer(BUF_WIDTH, SCREEN_HEIGHT, TexturePixelFormat::Psm8888);
         sys::sceGuInit();
         sys::sceGuStart(
             sys::GuContextType::Direct,
             &mut LIST as *mut _ as *mut c_void,
         );
-        sys::sceGuDrawBuffer(DisplayPixelFormat::Psm8888, fbp0, BUF_WIDTH as i32);
+        sys::sceGuDrawBuffer(DisplayPixelFormat::Psm8888, fbp0 as _, BUF_WIDTH as i32);
         sys::sceGuDebugPrint(100, 100, 0xff0000ff, b"Hello World\0" as *const u8);
         sys::sceGuDebugFlush();
 

psp/src/lib.rs

@@ -31,7 +31,7 @@ pub mod debug;
 #[macro_use] mod vfpu;
 mod eabi;
 pub mod sys;
-pub mod gu_utils;
+pub mod vram_alloc;
 
 #[cfg(not(feature = "stub-only"))] mod alloc_impl;
 #[cfg(not(feature = "stub-only"))] pub mod panic;

psp/src/vram_alloc.rs

@@ -0,0 +1,81 @@
+use crate::sys::TexturePixelFormat;
+use crate::sys::sceGeEdramGetSize;
+use core::mem::size_of;
+
+pub struct VramMemChunk {
+    start: u32,
+    len: u32,
+}
+
+impl VramMemChunk {
+    fn new(start: u32, len: u32) -> Self {
+        Self { start, len }
+    }
+
+    pub fn start(&self) -> u32 {
+        self.start
+    }
+
+    pub fn len(&self) -> u32 {
+        self.len
+    }
+}
+
+// A dead-simple VRAM bump allocator.
+pub struct SimpleVramAllocator {
+   offset: u32,
+}
+
+impl SimpleVramAllocator {
+    pub fn new() -> Self {
+        Self { offset: 0 }
+    }
+
+    pub fn alloc(&mut self, size: u32) -> VramMemChunk {
+        let old_offset = self.offset;
+        self.offset += size;
+
+        if self.offset > self.total_mem() {
+            panic!("Total VRAM size exceeded!");
+        }
+
+        VramMemChunk::new(old_offset, size)
+    }
+
+    pub fn alloc_sized<T: Sized>(&mut self, count: u32) -> VramMemChunk {
+        let size = size_of::<T>() as u32;
+        self.alloc(count * size)
+    }
+
+    pub fn alloc_texture_pixels(
+        &mut self,
+        width: u32,
+        height: u32,
+        psm: TexturePixelFormat,
+    ) -> VramMemChunk {
+        let size = get_memory_size(width, height, psm);
+        self.alloc(size)
+    }
+
+    fn total_mem(&self) -> u32 {
+        unsafe {
+            sceGeEdramGetSize()
+        }
+    }
+}
+
+fn get_memory_size(width: u32, height: u32, psm: TexturePixelFormat) -> u32 {
+    match psm {
+        TexturePixelFormat::PsmT4 => (width * height) >> 1,
+        TexturePixelFormat::PsmT8 => width * height,
+
+        TexturePixelFormat::Psm5650
+        | TexturePixelFormat::Psm5551
+        | TexturePixelFormat::Psm4444
+        | TexturePixelFormat::PsmT16 => 2 * width * height,
+
+        TexturePixelFormat::Psm8888 | TexturePixelFormat::PsmT32 => 4 * width * height,
+
+        _ => unimplemented!(),
+    }
+}