hw2: add screenshot pass

src/d_main.c

@@ -868,8 +868,10 @@ void D_SRB2Loop(void)
 		// Only take screenshots after drawing.
 		if (moviemode)
 			M_SaveFrame();
-		if (takescreenshot)
-			M_DoScreenShot();
+#ifdef HWRENDER
+		if (rendermode == render_opengl && takescreenshot)
+			M_DoLegacyGLScreenShot();
+#endif
 
 		// consoleplayer -> displayplayers (hear sounds from viewpoint)
 		S_UpdateSounds(); // move positional sounds

src/g_game.c

@@ -1603,8 +1603,6 @@ void G_PreLevelTitleCard(void)
 
         if (moviemode)
             M_SaveFrame();
-        if (takescreenshot) // Only take screenshots after drawing.
-            M_DoScreenShot();
 
         while (!((nowtime = I_GetTime()) - lasttime))
         {
@@ -4396,7 +4394,7 @@ void G_LoadGameData(void)
 	{
 		// Don't load, but do save. (essentially, reset)
 		gamedata->loaded = true;
-		return; 
+		return;
 	}
 
 	if (P_SaveBufferFromFile(&save, va(pandf, srb2home, gamedatafilename)) == false)

src/hwr2/CMakeLists.txt

@@ -9,6 +9,8 @@ target_sources(SRB2SDL2 PRIVATE
 	pass_postprocess.hpp
 	pass_resource_managers.cpp
 	pass_resource_managers.hpp
+	pass_screenshot.cpp
+	pass_screenshot.hpp
 	pass_software.cpp
 	pass_software.hpp
 	pass_twodee.cpp

src/hwr2/pass_screenshot.cpp

@@ -0,0 +1,68 @@
+// SONIC ROBO BLAST 2
+//-----------------------------------------------------------------------------
+// Copyright (C) 2023 by Ronald "Eidolon" Kinard
+//
+// This program is free software distributed under the
+// terms of the GNU General Public License, version 2.
+// See the 'LICENSE' file for more details.
+//-----------------------------------------------------------------------------
+
+#include "pass_screenshot.hpp"
+
+#include <tcb/span.hpp>
+
+#include "../m_misc.h"
+
+using namespace srb2;
+using namespace srb2::hwr2;
+using namespace srb2::rhi;
+
+ScreenshotPass::ScreenshotPass() = default;
+ScreenshotPass::~ScreenshotPass() = default;
+
+void ScreenshotPass::prepass(Rhi& rhi)
+{
+	if (!render_pass_)
+	{
+		render_pass_ = rhi.create_render_pass(
+			{
+				std::nullopt,
+				PixelFormat::kRGBA8,
+				AttachmentLoadOp::kLoad,
+				AttachmentStoreOp::kStore
+			}
+		);
+	}
+
+	doing_screenshot_ = takescreenshot;
+}
+
+void ScreenshotPass::transfer(Rhi& rhi, Handle<TransferContext> ctx)
+{
+}
+
+void ScreenshotPass::graphics(Rhi& rhi, Handle<GraphicsContext> ctx)
+{
+	if (!doing_screenshot_)
+	{
+		return;
+	}
+
+	pixel_data_.clear();
+	pixel_data_.resize(width_ * height_ * 3); // 3 bytes per pixel for RGB8
+
+	rhi.begin_render_pass(ctx, {render_pass_, source_, std::nullopt, {0.f, 0.f, 0.f, 0.f}});
+	rhi.read_pixels(ctx, {0, 0, width_, height_}, PixelFormat::kRGB8, tcb::as_writable_bytes(tcb::span(pixel_data_)));
+	rhi.end_render_pass(ctx);
+}
+
+void ScreenshotPass::postpass(Rhi& rhi)
+{
+	if (!doing_screenshot_)
+	{
+		return;
+	}
+
+	M_DoScreenShot(width_, height_, tcb::as_bytes(tcb::span(pixel_data_)));
+	doing_screenshot_ = false;
+}

src/hwr2/pass_screenshot.hpp

@@ -0,0 +1,49 @@
+// SONIC ROBO BLAST 2
+//-----------------------------------------------------------------------------
+// Copyright (C) 2023 by Ronald "Eidolon" Kinard
+//
+// This program is free software distributed under the
+// terms of the GNU General Public License, version 2.
+// See the 'LICENSE' file for more details.
+//-----------------------------------------------------------------------------
+
+#ifndef __SRB2_HWR2_PASS_SCREENSHOT_HPP__
+#define __SRB2_HWR2_PASS_SCREENSHOT_HPP__
+
+#include <cstddef>
+#include <vector>
+
+#include "pass.hpp"
+
+namespace srb2::hwr2
+{
+
+class ScreenshotPass : public Pass
+{
+	bool doing_screenshot_ = false;
+	rhi::Handle<rhi::Texture> source_;
+	rhi::Handle<rhi::RenderPass> render_pass_;
+	std::vector<uint8_t> pixel_data_;
+	uint32_t width_ = 0;
+	uint32_t height_ = 0;
+
+public:
+	ScreenshotPass();
+	virtual ~ScreenshotPass();
+
+	virtual void prepass(rhi::Rhi& rhi) override;
+	virtual void transfer(rhi::Rhi& rhi, rhi::Handle<rhi::TransferContext> ctx) override;
+	virtual void graphics(rhi::Rhi& rhi, rhi::Handle<rhi::GraphicsContext> ctx) override;
+	virtual void postpass(rhi::Rhi& rhi) override;
+
+	void set_source(rhi::Handle<rhi::Texture> source, uint32_t width, uint32_t height)
+	{
+		source_ = source;
+		width_ = width;
+		height_ = height;
+	}
+};
+
+} // namespace srb2::hwr2
+
+#endif // __SRB2_HWR2_PASS_SCREENSHOT_HPP__

src/i_video_common.cpp

@@ -22,6 +22,7 @@
 #include "hwr2/pass_manager.hpp"
 #include "hwr2/pass_postprocess.hpp"
 #include "hwr2/pass_resource_managers.hpp"
+#include "hwr2/pass_screenshot.hpp"
 #include "hwr2/pass_software.hpp"
 #include "hwr2/pass_twodee.hpp"
 #include "hwr2/twodee.hpp"
@@ -118,6 +119,7 @@ static std::shared_ptr<PassManager> build_pass_manager()
 	twodee->ctx_ = &g_2d;
 	std::shared_ptr<BlitRectPass> pp_simple_blit_pass = std::make_shared<BlitRectPass>(false);
 	std::shared_ptr<PostprocessWipePass> pp_wipe_pass = std::make_shared<PostprocessWipePass>();
+	std::shared_ptr<ScreenshotPass> screenshot_pass = std::make_shared<ScreenshotPass>();
 	std::shared_ptr<ImguiPass> imgui_pass = std::make_shared<ImguiPass>();
 	std::shared_ptr<BlitRectPass> final_composite_pass = std::make_shared<BlitRectPass>(true);
 
@@ -186,7 +188,7 @@ static std::shared_ptr<PassManager> build_pass_manager()
 			}
 			pp_simple_blit_pass->set_texture(color, vid.width, vid.height);
 			pp_simple_blit_pass
-				->set_output(framebuffer_manager->current_post_color(), vid.width, vid.height, false, true);
+				->set_output(framebuffer_manager->current_post_color(), vid.width, vid.height, false, false);
 		}
 	);
 	manager->insert("pp_final_simple_blit", pp_simple_blit_pass);
@@ -209,12 +211,21 @@ static std::shared_ptr<PassManager> build_pass_manager()
 		[framebuffer_manager](PassManager&, Rhi&) { framebuffer_manager->swap_post(); }
 	);
 
+	manager->insert(
+		"screenshot_prepare",
+		[screenshot_pass, framebuffer_manager](PassManager&, Rhi&)
+		{
+			screenshot_pass->set_source(framebuffer_manager->previous_post_color(), vid.width, vid.height);
+		}
+	);
+	manager->insert("screenshot", screenshot_pass);
+
 	manager->insert(
 		"final_composite_prepare",
 		[final_composite_pass, framebuffer_manager](PassManager&, Rhi&)
 		{
 			final_composite_pass->set_texture(framebuffer_manager->previous_post_color(), vid.width, vid.height);
-			final_composite_pass->set_output(kNullHandle, vid.realwidth, vid.realheight, true, true);
+			final_composite_pass->set_output(kNullHandle, vid.realwidth, vid.realheight, true, false);
 		}
 	);
 	manager->insert("final_composite", final_composite_pass);

src/m_misc.cpp

@@ -1509,7 +1509,7 @@ void M_StopMovie(void)
   * \param palette  Palette of image data.
   *  \note if palette is NULL, BGR888 format
   */
-boolean M_SavePNG(const char *filename, void *data, int width, int height, const UINT8 *palette)
+boolean M_SavePNG(const char *filename, const void *data, int width, int height, const UINT8 *palette)
 {
 	png_structp png_ptr;
 	png_infop png_info_ptr;
@@ -1580,7 +1580,7 @@ boolean M_SavePNG(const char *filename, void *data, int width, int height, const
 
 	png_write_info(png_ptr, png_info_ptr);
 
-	M_PNGImage(png_ptr, png_info_ptr, height, static_cast<png_bytep>(data));
+	M_PNGImage(png_ptr, png_info_ptr, height, (png_bytep)data);
 
 	png_write_end(png_ptr, png_info_ptr);
 	png_destroy_write_struct(&png_ptr, &png_info_ptr);
@@ -1688,19 +1688,24 @@ void M_ScreenShot(void)
 	takescreenshot = true;
 }
 
+void M_DoLegacyGLScreenShot(void)
+{
+	const std::byte* fake_data = nullptr;
+	M_DoScreenShot(vid.width, vid.height, tcb::span(fake_data, vid.width * vid.height));
+}
+
 /** Takes a screenshot.
   * The screenshot is saved as "srb2xxxx.png" where xxxx is the lowest
   * four-digit number for which a file does not already exist.
   *
   * \sa HWR_ScreenShot
   */
-void M_DoScreenShot(void)
+void M_DoScreenShot(UINT32 width, UINT32 height, tcb::span<const std::byte> data)
 {
 #if NUMSCREENS > 2
 	const char *freename = NULL;
 	char pathname[MAX_WADPATH];
 	boolean ret = false;
-	UINT8 *linear = NULL;
 
 	// Don't take multiple screenshots, obviously
 	takescreenshot = false;
@@ -1733,13 +1738,6 @@ void M_DoScreenShot(void)
 		freename = Newsnapshotfile(pathname,"tga");
 #endif
 
-	if (rendermode == render_soft)
-	{
-		// munge planar buffer to linear
-		linear = screens[2];
-		I_ReadScreen(linear);
-	}
-
 	if (!freename)
 		goto failure;
 
@@ -1750,9 +1748,9 @@ void M_DoScreenShot(void)
 	else
 #endif
 	{
-		M_CreateScreenShotPalette();
+		const void* pixel_data = static_cast<const void*>(data.data());
 #ifdef USE_PNG
-		ret = M_SavePNG(va(pandf,pathname,freename), linear, vid.width, vid.height, screenshot_palette);
+		ret = M_SavePNG(va(pandf,pathname,freename), pixel_data, width, height, NULL);
 #else
 		ret = WritePCXfile(va(pandf,pathname,freename), linear, vid.width, vid.height, screenshot_palette);
 #endif

src/m_misc.h

@@ -22,6 +22,13 @@
 #include "command.h"
 
 #ifdef __cplusplus
+
+#include <cstddef>
+
+#include <tcb/span.hpp>
+
+void M_DoScreenShot(uint32_t width, uint32_t height, tcb::span<const std::byte> data);
+
 extern "C" {
 #endif
 
@@ -82,12 +89,14 @@ void FIL_ForceExtension(char *path, const char *extension);
 boolean FIL_CheckExtension(const char *in);
 
 #ifdef HAVE_PNG
-boolean M_SavePNG(const char *filename, void *data, int width, int height, const UINT8 *palette);
+boolean M_SavePNG(const char *filename, const void *data, int width, int height, const UINT8 *palette);
 #endif
 
 extern boolean takescreenshot;
 void M_ScreenShot(void);
-void M_DoScreenShot(void);
+#ifdef HWRENDER
+void M_DoLegacyGLScreenShot(void);
+#endif
 boolean M_ScreenshotResponder(event_t *ev);
 
 void M_MinimapGenerate(void);

src/rhi/gl3_core/gl3_core_rhi.cpp

@@ -42,6 +42,12 @@ constexpr GLenum map_pixel_format(rhi::PixelFormat format)
 {
 	switch (format)
 	{
+	case rhi::PixelFormat::kR8:
+		return GL_R8;
+	case rhi::PixelFormat::kRG8:
+		return GL_RG8;
+	case rhi::PixelFormat::kRGB8:
+		return GL_RGB8;
 	case rhi::PixelFormat::kRGBA8:
 		return GL_RGBA8;
 	case rhi::PixelFormat::kDepth16:
@@ -70,6 +76,11 @@ constexpr std::tuple<GLenum, GLenum, GLuint> map_pixel_data_format(rhi::PixelFor
 		type = GL_UNSIGNED_BYTE;
 		size = 2;
 		break;
+	case rhi::PixelFormat::kRGB8:
+		layout = GL_RGB;
+		type = GL_UNSIGNED_BYTE;
+		size = 3;
+		break;
 	case rhi::PixelFormat::kRGBA8:
 		layout = GL_RGBA;
 		type = GL_UNSIGNED_BYTE;
@@ -1581,13 +1592,19 @@ void GlCoreRhi::draw_indexed(Handle<GraphicsContext> ctx, uint32_t index_count,
 	GL_ASSERT
 }
 
-void GlCoreRhi::read_pixels(Handle<GraphicsContext> ctx, const Rect& rect, tcb::span<std::byte> out)
+void GlCoreRhi::read_pixels(Handle<GraphicsContext> ctx, const Rect& rect, PixelFormat format, tcb::span<std::byte> out)
 {
 	SRB2_ASSERT(graphics_context_active_ == true && graphics_context_generation_ == ctx.generation());
 	SRB2_ASSERT(current_render_pass_.has_value());
 
-	SRB2_ASSERT(out.size_bytes() == rect.w * rect.h);
-	gl_->ReadPixels(rect.x, rect.y, rect.w, rect.h, GL_RGBA, GL_UNSIGNED_BYTE, out.data());
+	std::tuple<GLenum, GLenum, GLuint> gl_format = map_pixel_data_format(format);
+	GLenum layout = std::get<0>(gl_format);
+	GLenum type = std::get<1>(gl_format);
+	GLint size = std::get<2>(gl_format);
+
+	SRB2_ASSERT(out.size_bytes() == rect.w * rect.h * size);
+
+	gl_->ReadPixels(rect.x, rect.y, rect.w, rect.h, layout, type, out.data());
 }
 
 void GlCoreRhi::finish()

src/rhi/gl3_core/gl3_core_rhi.hpp

@@ -226,7 +226,8 @@ public:
 	virtual void set_viewport(Handle<GraphicsContext> ctx, const Rect& rect) override;
 	virtual void draw(Handle<GraphicsContext> ctx, uint32_t vertex_count, uint32_t first_vertex) override;
 	virtual void draw_indexed(Handle<GraphicsContext> ctx, uint32_t index_count, uint32_t first_index) override;
-	virtual void read_pixels(Handle<GraphicsContext> ctx, const Rect& rect, tcb::span<std::byte> out) override;
+	virtual void
+	read_pixels(Handle<GraphicsContext> ctx, const Rect& rect, PixelFormat format, tcb::span<std::byte> out) override;
 
 	virtual void present() override;
 

src/rhi/rhi.hpp

@@ -73,6 +73,7 @@ enum class PixelFormat
 {
 	kR8,
 	kRG8,
+	kRGB8,
 	kRGBA8,
 	kDepth16,
 	kStencil8
@@ -562,7 +563,8 @@ struct Rhi
 	virtual void set_viewport(Handle<GraphicsContext> ctx, const Rect& rect) = 0;
 	virtual void draw(Handle<GraphicsContext> ctx, uint32_t vertex_count, uint32_t first_vertex) = 0;
 	virtual void draw_indexed(Handle<GraphicsContext> ctx, uint32_t index_count, uint32_t first_index) = 0;
-	virtual void read_pixels(Handle<GraphicsContext> ctx, const Rect& rect, tcb::span<std::byte> out) = 0;
+	virtual void
+	read_pixels(Handle<GraphicsContext> ctx, const Rect& rect, PixelFormat format, tcb::span<std::byte> out) = 0;
 
 	virtual void present() = 0;