Parse a cube .obj file to display.

Right now the implementation is extremely unoptimized and draw call heavy as I just copy and pasted that from the docs for tiny obj loader but added gl calls.

.vscode/launch.json

@@ -28,6 +28,64 @@
 			],
 			"avoidWindowsConsoleRedirection": false,
 			"internalConsoleOptions": "openOnSessionStart"
+		},
+		{
+			"name": "(gdb) Launch cube.elf",
+			"type": "cppdbg",
+			"request": "launch",
+			"program": "${workspaceFolder}/build/cube.elf",
+			"args": [],
+			"stopAtEntry": false,
+			"cwd": "${workspaceFolder}",
+			"environment": [],
+			"externalConsole": false,
+			"MIMode": "gdb",
+			"miDebuggerPath": "/opt/toolchains/dc/sh-elf/bin/sh-elf-gdb",
+			"miDebuggerServerAddress": "localhost:3263",
+			"debugServerPath": "/usr/bin/flycast",
+			"debugServerArgs": "${workspaceFolder}/build/cube.elf",
+			"setupCommands": [
+				{
+					"description": "Enable pretty-printing for gdb",
+					"text": "-enable-pretty-printing",
+					"ignoreFailures": true
+				},
+				{
+					"description": "Set SuperH architechture",
+					"text": "set architecture sh4"
+				}
+			],
+			"avoidWindowsConsoleRedirection": false,
+			"internalConsoleOptions": "openOnSessionStart"
+		},
+		{
+			"name": "(gdb, lxdream-nitro) Launch cube.elf",
+			"type": "cppdbg",
+			"request": "launch",
+			"program": "${workspaceFolder}/build/cube.elf",
+			"args": [],
+			"stopAtEntry": false,
+			"cwd": "${workspaceFolder}",
+			"environment": [],
+			"externalConsole": false,
+			"MIMode": "gdb",
+			"miDebuggerPath": "/opt/toolchains/dc/sh-elf/bin/sh-elf-gdb",
+			"miDebuggerServerAddress": "localhost:3263",
+			"debugServerPath": "/home/user/Downloads/lxdream-nitro/builddir/lxdream-nitro",
+			"debugServerArgs": "-d -g 3263 -e ${workspaceFolder}/build/cube.elf",
+			"setupCommands": [
+				{
+					"description": "Enable pretty-printing for gdb",
+					"text": "-enable-pretty-printing",
+					"ignoreFailures": true
+				},
+				{
+					"description": "Set SuperH architechture",
+					"text": "set architecture sh4"
+				}
+			],
+			"avoidWindowsConsoleRedirection": false,
+			"internalConsoleOptions": "openOnSessionStart"
 		}
 	]
 }

cube.cc

@@ -0,0 +1,145 @@
+#include <GL/gl.h>
+#include <GL/glext.h>
+#include <GL/glkos.h>
+#include <GL/glu.h>
+#include <stb_image/stb_image.h>
+#include <tiny_obj_loader.h>
+
+#include <cstdio>
+#include "engine.hh"
+
+class Cube : public Engine {
+	unsigned int texture;
+	tinyobj::ObjReader reader;
+
+	bool parseObj(std::string objFile, tinyobj::ObjReader& reader);
+	void cube();
+	void displayStuff();
+	void gameLoop() override { displayStuff(); }
+	void initScreen() override;
+	void model();
+};
+
+void Cube::model() {
+	const tinyobj::attrib_t& attrib = reader.GetAttrib();
+	auto& shapes = reader.GetShapes();
+	angle += 1.0f;
+	glRotatef(angle, 1.0f, 0.0f, 1.0f);
+
+	int drawCalls = 0;
+
+	for (size_t s = 0; s < shapes.size(); s++) {
+		// Loop over faces(polygon)
+		size_t index_offset = 0;
+		for (size_t f = 0; f < shapes[s].mesh.num_face_vertices.size(); f++) {
+			size_t fv = size_t(shapes[s].mesh.num_face_vertices[f]);
+
+			glBegin(GL_TRIANGLES);
+			// Loop over vertices in the face.
+			for (size_t v = 0; v < fv; v++) {
+				// access to vertex
+				tinyobj::index_t idx = shapes[s].mesh.indices[index_offset + v];
+				tinyobj::real_t vx =
+					attrib.vertices[3 * size_t(idx.vertex_index) + 0];
+				tinyobj::real_t vy =
+					attrib.vertices[3 * size_t(idx.vertex_index) + 1];
+				tinyobj::real_t vz =
+					attrib.vertices[3 * size_t(idx.vertex_index) + 2];
+				glVertex3f(vx, vy, vz);
+				drawCalls += 1;
+				
+
+				// Check if `normal_index` is zero or positive. negative = no
+				// normal data
+				if (idx.normal_index >= 0) {
+					tinyobj::real_t nx =
+						attrib.normals[3 * size_t(idx.normal_index) + 0];
+					tinyobj::real_t ny =
+						attrib.normals[3 * size_t(idx.normal_index) + 1];
+					tinyobj::real_t nz =
+						attrib.normals[3 * size_t(idx.normal_index) + 2];
+					glNormal3f(nx, ny, nz);
+					drawCalls += 1;
+				}
+
+				// Check if `texcoord_index` is zero or positive. negative = no
+				// texcoord data
+				if (idx.texcoord_index >= 0) {
+					tinyobj::real_t tx =
+						attrib.texcoords[2 * size_t(idx.texcoord_index) + 0];
+					tinyobj::real_t ty =
+						attrib.texcoords[2 * size_t(idx.texcoord_index) + 1];
+					glTexCoord2f(tx, ty);
+					drawCalls += 1;
+				}
+			}
+			index_offset += fv;
+
+			glEnd();
+		}
+	}
+	printf("Draw Calls: %i\n", drawCalls);
+	drawCalls = 0;
+
+	// glDrawArrays(GL_QUADS, 0, susSize);
+}
+
+bool Cube::parseObj(std::string objFile, tinyobj::ObjReader& reader) {
+	tinyobj::ObjReaderConfig readerConfig;
+	readerConfig.mtl_search_path = "./";
+	if (!reader.ParseFromFile(objFile, readerConfig)) {
+		if (!reader.Error().empty()) {
+			printf("TinyOBJReader: %s\n", reader.Error().c_str());
+			return false;
+		}
+	}
+	return true;
+}
+
+void Cube::displayStuff() {
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glLoadIdentity();
+	glTranslatef(0.0f, 0.0f, -5.0f);
+	glRotatef(90, 0.0f, 1.0f, 0.5f);
+	model();
+	glKosSwapBuffers();
+}
+
+void Cube::initScreen() {
+	glKosInit();
+
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	gluPerspective(45.0f, 640.0f / 480.0f, 0.1f, 100.0f);
+	glMatrixMode(GL_MODELVIEW);
+	glEnable(GL_TEXTURE_2D);
+	glEnable(GL_DEPTH_TEST);
+	glFrontFace(GL_CW);
+
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+	glGenTextures(1, &texture);
+	glBindTexture(GL_TEXTURE_2D, texture);
+
+	int width, height, nr_channels;
+	unsigned char* data =
+		stbi_load("/rd/sanic.png", &width, &height, &nr_channels, 0);
+
+	if (data) {
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA,
+					 GL_UNSIGNED_BYTE, data);
+		glGenerateMipmap(GL_TEXTURE_2D);
+	} else {
+		printf("Texture failed to load.\n");
+	}
+
+	stbi_image_free(data);
+
+	if (!parseObj("/rd/cube.obj", reader)) return;
+}
+
+int main() {
+	Cube engine;
+	engine.initializeEngine();
+	engine.initializeGameLoop();
+}

engine.cc

@@ -1,3 +1,5 @@
+#define TINYOBJLOADER_IMPLEMENTATION
+
 #include "engine.hh"
 
 #include <GL/gl.h>
@@ -65,9 +67,7 @@ void Engine::pressButton(cont_state_t* controller_state, int button,
 }
 
 void Engine::glVertex3fNormalized(float x, float y, float z) {
-	int xSize, ySize;
+	constexpr int xSize = 640, ySize = 480;
-	xSize = 640;
-	ySize = 480;
 
 	glVertex3f(x * xSize, y * ySize, z);
 }

engine.hh

@@ -8,7 +8,7 @@
 
 class Engine {
    protected:
-	const float microSecond = 0.000001f;
+	static constexpr float microSecond = 0.000001f;
 
 	float angle = 0;
 	float deltaTime = 1.0 / 60.0;
@@ -17,7 +17,7 @@ class Engine {
 	bool thirtyfps;
 	unsigned int buttonsPressed;
 
-	void initScreen();
+	virtual void initScreen();
 	void printSystemInformation();
 	virtual void gameLoop(){};
 	void pressButton(cont_state_t* controller_state, int button,

meson.build

@@ -9,12 +9,18 @@ kosportsinc = include_directories('/opt/toolchains/dc/kos-ports/include')
 
 GL = cc.find_library('GL', required: true)
 math = cc.find_library('m', required: true)
+stb_image = cc.find_library('stb_image', required: true)
+subdir('romdisk')
+tinyobjloader = subproject('tinyobjloader')
+tinyobjloader_dep = tinyobjloader.get_variable('tinyobjloader_dep')
 # pcx = cc.find_library('pcx', required: true)
 # kosutils = cc.find_library('kosutils', required: true)
 
 deps = [
 	GL,
-	math
+	math,
+	stb_image,
+	tinyobjloader_dep
 ]
 
 incdirs = [
@@ -24,5 +30,11 @@ incdirs = [
 	kosportsinc
 ]
 
-executable('hello.elf', ['hello.cc', 'engine.cc'], dependencies: deps, include_directories: incdirs)
+engine = static_library('engine', ['engine.cc'], dependencies: deps, include_directories: incdirs)
-executable('gl.elf', ['gl.cc', 'engine.cc'], dependencies: deps, include_directories: incdirs)
+engine_dep = declare_dependency(link_with: engine, include_directories: incdirs)
+
+deps += [engine_dep]
+
+executable('hello.elf', ['hello.cc'], dependencies: deps, include_directories: incdirs)
+executable('gl.elf', ['gl.cc'], dependencies: deps, include_directories: incdirs)
+executable('cube.elf', ['cube.cc', romdsk_o], dependencies: deps, include_directories: incdirs)

romdisk/cube.mtl

@@ -0,0 +1,2 @@
+# Blender 4.0.2 MTL File: 'None'
+# www.blender.org

romdisk/cube.obj

@@ -0,0 +1,45 @@
+# Blender 4.0.2
+# www.blender.org
+mtllib cube.mtl
+o Cube
+v -1.000000 -1.000000 1.000000
+v -1.000000 1.000000 1.000000
+v -1.000000 -1.000000 -1.000000
+v -1.000000 1.000000 -1.000000
+v 1.000000 -1.000000 1.000000
+v 1.000000 1.000000 1.000000
+v 1.000000 -1.000000 -1.000000
+v 1.000000 1.000000 -1.000000
+vn -1.0000 -0.0000 -0.0000
+vn -0.0000 -0.0000 -1.0000
+vn 1.0000 -0.0000 -0.0000
+vn -0.0000 -0.0000 1.0000
+vn -0.0000 -1.0000 -0.0000
+vn -0.0000 1.0000 -0.0000
+vt 0.625000 0.000000
+vt 0.375000 0.250000
+vt 0.375000 0.000000
+vt 0.625000 0.250000
+vt 0.375000 0.500000
+vt 0.625000 0.500000
+vt 0.375000 0.750000
+vt 0.625000 0.750000
+vt 0.375000 1.000000
+vt 0.125000 0.750000
+vt 0.125000 0.500000
+vt 0.875000 0.500000
+vt 0.625000 1.000000
+vt 0.875000 0.750000
+s 0
+f 2/1/1 3/2/1 1/3/1
+f 4/4/2 7/5/2 3/2/2
+f 8/6/3 5/7/3 7/5/3
+f 6/8/4 1/9/4 5/7/4
+f 7/5/5 1/10/5 3/11/5
+f 4/12/6 6/8/6 8/6/6
+f 2/1/1 4/4/1 3/2/1
+f 4/4/2 8/6/2 7/5/2
+f 8/6/3 6/8/3 5/7/3
+f 6/8/4 2/13/4 1/9/4
+f 7/5/5 5/7/5 1/10/5
+f 4/12/6 2/14/6 6/8/6

romdisk/meson.build

@@ -0,0 +1,24 @@
+romdiskcomp = find_program('/opt/toolchains/dc/kos/utils/genromfs/genromfs')
+bin2o = find_program('/opt/toolchains/dc/kos/utils/bin2o/bin2o')
+cc = find_program('/opt/toolchains/dc/sh-elf/bin/sh-elf-gcc')
+kos_libs =['-L/opt/toolchains/dc/kos/lib/dreamcast','-L/opt/toolchains/dc/kos/addons/lib/dreamcast','-L/opt/toolchains/dc/kos/../kos-ports/lib']
+
+romdisk_path = join_paths(meson.current_source_dir())
+
+romdisk_img = custom_target('romdisk.img', 
+	output : 'romdisk.img',
+	build_always_stale: true,
+	command: [
+		romdiskcomp, '-f', '@OUTPUT@', '-d', romdisk_path, '-v', '-x', '.svn', '-x', '.keepme', '-x', 'meson.build'
+	])
+
+romdsk = custom_target('romdisk_tmp.o', 
+	output : 'romdisk_tmp.o',
+	input: [romdisk_img],
+	command: [
+		bin2o, '@INPUT@', 'romdisk', '@OUTPUT@'
+	])
+
+romdsk_o = custom_target('romdisk.o', output: 'romdisk.o', input: [romdsk], command: [
+	cc, '-o', '@OUTPUT@', '-r', '@INPUT@', '-Wl,--whole-archive', kos_libs, '-lromdiskbase'
+])

subprojects/.gitignore

@@ -0,0 +1,3 @@
+*
+!*.wrap
+!.gitignore

subprojects/tinyobjloader.wrap

@@ -0,0 +1,8 @@
+[wrap-git]
+url = https://github.com/tinyobjloader/tinyobjloader
+revision = cab4ad7254cbf7eaaafdb73d272f99e92f166df8
+depth = 1
+method = cmake
+
+[provide]
+tinyobjloader = tinyobjloader_dep