Added some useful info on perspective transformations based on research. Also added a math source file with a custom rotation matrix routine, which isn't quite working as it should yet.

CMakeLists.txt

@@ -11,7 +11,8 @@ project(
 	HOMEPAGE_URL "http://lameguy64.net/?page=psn00bsdk"
 )
 
-psn00bsdk_add_executable(template STATIC main.c)
+file(GLOB _sources *.c)
+psn00bsdk_add_executable(template STATIC ${_sources})
 
 psn00bsdk_target_incbin(template PRIVATE mdl_player player.ps1mdl)
 psn00bsdk_target_incbin(template PRIVATE tim_player_f player_f.tim)

main.c

@@ -25,6 +25,7 @@
 #include <psxgpu.h>
 #include <inline_c.h>
 #include "ps1mdl.h"
+#include "qmath.h"
 
 #define OTLEN	1024
 
@@ -213,7 +214,7 @@ void init(void)
 	FntLoad(960, 0);
 	
 	// Open up a test font text stream of 100 characters
-	FntOpen(0, 8, 320, 224, 0, 100);
+	FntOpen(0, 8, SCREENWIDTH, SCREENHEIGHT, 0, 200);
 
 	nextpri = primbuff[0];
 
@@ -229,9 +230,13 @@ void init(void)
 	loadModel(mdl_quaddama, &quadModel);
 	loadSkin(tim_quaddama_f, tim_quaddama_b, &quadSkin);
 
+	// Perspective calculations are quite simple, with Go = GeomOffset and Gs = GeomScreen, view coordinates are transformed to screen coordinates as such:
+	// x' = vx * Gs / vz + Go.x
+	// y' = vy * Gs / vz + Go.y
+	// z' = (vz - 1) / 4 (depth does not appear to be affected by any parameters)
 	InitGeom();
 	gte_SetGeomOffset(SCREENWIDTH >> 1, SCREENHEIGHT >> 1);
-	gte_SetGeomScreen(180);	// Screen depth for FOV control. Essentially the Z position of the vanishing point.
+	gte_SetGeomScreen(180);	// Screen depth for FOV control. Determines the distance of the camera to the near plane.
 
 	// Set texture page for the entire drawing environment. Nice in some cases perhaps, but not what we need.
 	//draw[0].tpage = getTPage(playerFrontTex.mode & 0x3, 0, playerFrontTex.prect->x, playerFrontTex.prect->y);
@@ -415,7 +420,7 @@ void drawModel(MATRIX *view_matrix, ps1mdl_t *model, ps1skin_t *skin, int frameC
 
 	// Model world position and rotation
 	MATRIX model_mtx;
-	RotMatrix(&model->rotation, &model_mtx);
+	RotMatrixQ(&model->rotation, &model_mtx);
 	TransMatrix(&model_mtx, &model->position);
 
 	// Adjust light direction by the model's rotation relative to the world
@@ -525,13 +530,6 @@ void drawStuff(int counter)
 {
 	ClearOTagR(ot[db], OTLEN);
 
-	FntPrint(-1, "Image x %d y %d w %d h %d mode 0x%x\n", playerSkin.front.prect.x, playerSkin.front.prect.y, playerSkin.front.prect.w, playerSkin.front.prect.h, playerSkin.front.mode);
-	FntPrint(-1, "Model: %d tris, %d verts\n", playerModel.header->triangleCount, playerModel.header->vertexCount);
-	FntPrint(-1, "Trsf: (%d, %d, %d)\n", outPos.vx, outPos.vy, outPos.vz);
-	
-	// Draw the last created text stream
-	FntFlush(-1);
-
 	gte_SetBackColor(48, 48, 48);		// Ambient light color
 	gte_SetColorMatrix(&light_cols);	// Light color (up to three different lights)
 
@@ -541,7 +539,7 @@ void drawStuff(int counter)
 	MATRIX view_matrix;
 	SVECTOR trot = { -cam_rot.vx, -cam_rot.vy, -cam_rot.vz, 0 };	// Inverse camera rotation (in Quake coordinates)
 	VECTOR tpos = { -cam_pos.vx, -cam_pos.vy, -cam_pos.vz };		// Inverse camera position (in Quake coordinates)
-	RotMatrix(&trot, &view_matrix);		// Set camera rotation part of the view matrix
+	RotMatrixQ(&trot, &view_matrix);		// Set camera rotation part of the view matrix
 	ApplyMatrixLV(&view_matrix, &tpos, &tpos);	// Apply camera rotation to camera position
 	TransMatrix(&view_matrix, &tpos);	// Apply transformed position to the translation part of the view matrix
 
@@ -552,6 +550,13 @@ void drawStuff(int counter)
 	drawModel(&view_matrix, &shamblerModel, &shamblerSkin, counter >> 2);
 	//drawModel(&view_matrix, &ogreModel, &ogreSkin, counter >> 2);
 	drawModel(&view_matrix, &quadModel, &quadSkin, 0);
+	
+	FntPrint(-1, "Camera pos = (%d, %d, %d) rot = (%d, %d, %d)\n", cam_pos.vx, cam_pos.vy, cam_pos.vz, cam_rot.vx, cam_rot.vy, cam_rot.vz);
+	FntPrint(-1, "Model: %d tris, %d verts\n", playerModel.header->triangleCount, playerModel.header->vertexCount);
+	FntPrint(-1, "Trsf: (%d, %d, %d)\n", outPos.vx, outPos.vy, outPos.vz);
+
+	// Draw the last created text stream
+	FntFlush(-1);
 }
 
 void handleInput()
@@ -566,19 +571,19 @@ void handleInput()
 
 	// Determine direction vectors of the camera
 	MATRIX cam_mtx;
-	RotMatrix(&cam_rot, &cam_mtx);
+	RotMatrixQ(&cam_rot, &cam_mtx);
 
 	u_short buttons = *((u_short*)(padBuffer[0]+2));
 	if (!(buttons & PAD_UP))
 	{
-		// Move forward
+		// Move forward (+Y)
 		cam_pos.vx += (cam_mtx.m[0][1] * moveSpeed) >> 12;
 		cam_pos.vy += (cam_mtx.m[1][1] * moveSpeed) >> 12;
 		cam_pos.vz += (cam_mtx.m[2][1] * moveSpeed) >> 12;
 	}
 	if (!(buttons & PAD_DOWN))
 	{
-		// Move backward
+		// Move backward (-Y)
 		cam_pos.vx -= (cam_mtx.m[0][1] * moveSpeed) >> 12;
 		cam_pos.vy -= (cam_mtx.m[1][1] * moveSpeed) >> 12;
 		cam_pos.vz -= (cam_mtx.m[2][1] * moveSpeed) >> 12;
@@ -595,28 +600,28 @@ void handleInput()
 	}
 	if (!(buttons & PAD_TRIANGLE))
 	{
-		// Move up
+		// Move up (+Z)
 		cam_pos.vx += (cam_mtx.m[0][2] * moveSpeed) >> 12;
 		cam_pos.vy += (cam_mtx.m[1][2] * moveSpeed) >> 12;
 		cam_pos.vz += (cam_mtx.m[2][2] * moveSpeed) >> 12;
 	}
 	if (!(buttons & PAD_CROSS))
 	{
-		// Move down
+		// Move down (-Z)
 		cam_pos.vx -= (cam_mtx.m[0][2] * moveSpeed) >> 12;
 		cam_pos.vy -= (cam_mtx.m[1][2] * moveSpeed) >> 12;
 		cam_pos.vz -= (cam_mtx.m[2][2] * moveSpeed) >> 12;
 	}
 	if (!(buttons & PAD_L1))
 	{
-		// Strafe left
+		// Strafe left (-X)
 		cam_pos.vx -= (cam_mtx.m[0][0] * moveSpeed) >> 12;
 		cam_pos.vy -= (cam_mtx.m[1][0] * moveSpeed) >> 12;
 		cam_pos.vz -= (cam_mtx.m[2][0] * moveSpeed) >> 12;
 	}
 	if (!(buttons & PAD_R1))
 	{
-		// Strafe right
+		// Strafe right (+X)
 		cam_pos.vx += (cam_mtx.m[0][0] * moveSpeed) >> 12;
 		cam_pos.vy += (cam_mtx.m[1][0] * moveSpeed) >> 12;
 		cam_pos.vz += (cam_mtx.m[2][0] * moveSpeed) >> 12;

qmath.c

@@ -0,0 +1,34 @@
+#include "qmath.h"
+
+MATRIX *RotMatrixQ(SVECTOR *r, MATRIX *m)
+{
+	short s[3],c[3];
+	MATRIX tm[3];
+
+	s[0] = isin(r->vx);		s[1] = isin(r->vy);		s[2] = isin(r->vz);
+	c[0] = icos(r->vx);		c[1] = icos(r->vy);		c[2] = icos(r->vz);
+
+	// mY (roll)
+	m->m[0][0] = c[1];	m->m[0][1] = 0;		m->m[0][2] = s[1];
+	m->m[1][0] = 0;		m->m[1][1] = ONE;	m->m[1][2] = 0;
+	m->m[2][0] = -s[1];	m->m[2][1] = 0;		m->m[2][2] = c[1];
+
+	// mX (pitch)
+	tm[0].m[0][0] = ONE;		tm[0].m[0][1] = 0;			tm[0].m[0][2] = 0;
+	tm[0].m[1][0] = 0;			tm[0].m[1][1] = c[0];		tm[0].m[1][2] = -s[0];
+	tm[0].m[2][0] = 0;			tm[0].m[2][1] = s[0];		tm[0].m[2][2] = c[0];
+
+    // mZ (yaw)
+	tm[1].m[0][0] = c[2];	tm[1].m[0][1] = -s[2];	tm[1].m[0][2] = 0;
+	tm[1].m[1][0] = s[2];	tm[1].m[1][1] = c[2];	tm[1].m[1][2] = 0;
+	tm[1].m[2][0] = 0;		tm[1].m[2][1] = 0;		tm[1].m[2][2] = ONE;
+
+	PushMatrix();
+
+	MulMatrix0( m, &tm[1], &tm[2] );
+	MulMatrix0( &tm[2], &tm[0], m );
+
+	PopMatrix();
+
+	return m;
+}

qmath.h

@@ -0,0 +1,8 @@
+#ifndef __QMATH_H__
+#define __QMATH_H__
+
+#include <psxgte.h>
+
+MATRIX *RotMatrixQ(SVECTOR *r, MATRIX *m);
+
+#endif // __QMATH_H__