1 files changed, 212 insertions, 0 deletions
diff --git a/libpsn00b/psxgpu/env.c b/libpsn00b/psxgpu/env.c
new file mode 100644
index 0000000..5642ad4
--- /dev/null
+++ b/libpsn00b/psxgpu/env.c
@@ -0,0 +1,212 @@
+/*
+ * PSn00bSDK GPU library (DRAWENV/DISPENV functions)
+ * (C) 2022 spicyjpeg - MPL licensed
+ */
+
+#include <stdint.h>
+#include <psxgpu.h>
+#include <hwregs_c.h>
+
+#define _min(x, y) (((x) < (y)) ? (x) : (y))
+
+extern GPU_VideoMode _gpu_video_mode;
+
+/* Drawing API */
+
+DRAWENV *SetDefDrawEnv(DRAWENV *env, int x, int y, int w, int h) {
+	env->clip.x = x;
+	env->clip.y = y;
+	env->clip.w = w;
+	env->clip.h = h;
+
+	env->ofs[0] = 0;
+	env->ofs[1] = 0;
+
+	env->tw.x = 0;
+	env->tw.y = 0;
+	env->tw.w = 0;
+	env->tw.h = 0;
+
+	env->tpage = 0x0a;
+	env->dtd   = 1;
+	env->dfe   = 0;
+	env->isbg  = 0;
+	setRGB0(env, 0, 0, 0);
+
+	env->dr_env.tag = 0;
+	return env;
+}
+
+void DrawOTagEnv(const uint32_t *ot, DRAWENV *env) {
+	DR_ENV *prim = &(env->dr_env);
+
+	// All commands are grouped into a single display list packet for
+	// performance reasons (keep in mind that the GPU doesn't care about this
+	// as the display list is parsed by the DMA unit in the CPU and only the
+	// payload is sent to the GPU).
+	setaddr(prim, ot);
+	setlen(prim, 4);
+
+	// Set drawing area top left
+	prim->code[0]  = 0xe3000000;
+	prim->code[0] |=  env->clip.x & 0x3ff;
+	prim->code[0] |= (env->clip.y & 0x3ff) << 10;
+
+	// Set drawing area bottom right
+	prim->code[1]  = 0xe4000000;
+	prim->code[1] |=  (env->clip.x + (env->clip.w - 1)) & 0x3ff;
+	prim->code[1] |= ((env->clip.y + (env->clip.h - 1)) & 0x3ff) << 10;
+
+	// Set drawing offset
+	prim->code[2]  = 0xe5000000;
+	prim->code[2] |=  (env->clip.x + env->ofs[0]) & 0x7ff;
+	prim->code[2] |= ((env->clip.y + env->ofs[1]) & 0x7ff) << 11;
+
+	// Texture page (reset active page and set dither/mask bits)
+	prim->code[3]  = 0xe1000000;
+	prim->code[3] |= (env->dtd & 1) << 9;
+	prim->code[3] |= (env->dfe & 1) << 10;
+
+	if (env->isbg) {
+		setlen(prim, 7);
+
+		// Rectangle fill
+		// FIXME: reportedly this command doesn't accept height values >511...
+		prim->code[4]  = 0x02000000;
+		//prim->code[4] |= env->r0 | (env->g0 << 8) | (env->b0 << 16);
+		prim->code[4] |= *((const uint32_t *) &(env->isbg)) >> 8;
+		//prim->code[5]  = env->clip.x;
+		//prim->code[5] |= env->clip.y << 16;
+		prim->code[5]  = *((const uint32_t *) &(env->clip.x));
+		prim->code[6]  = env->clip.w;
+		prim->code[6] |= _min(env->clip.h, 0x1ff) << 16;
+	}
+
+	//while (!(GPU_GP1 & (1 << 26)))
+		//__asm__ volatile("");
+
+	DrawOTag((const uint32_t *) prim);
+}
+
+void PutDrawEnv(DRAWENV *env) {
+	DrawOTagEnv((const uint32_t *) 0x00ffffff, env);
+}
+
+// This function skips rebuilding the cached packet whenever possible and is
+// useful if the DRAWENV structure is never modified (which is the case most of
+// the time).
+void PutDrawEnvFast(DRAWENV *env) {
+	if (!(env->dr_env.tag)) {
+		DrawOTagEnv((const uint32_t *) 0x00ffffff, env);
+		return;
+	}
+
+	DrawOTag((const uint32_t *) &(env->dr_env));
+}
+
+/* Display API */
+
+DISPENV *SetDefDispEnv(DISPENV *env, int x, int y, int w, int h) {
+	env->disp.x = x;
+	env->disp.y = y;
+	env->disp.w = w;
+	env->disp.h = h;
+
+	env->screen.x = 0;
+	env->screen.y = 0;
+	env->screen.w = 0;
+	env->screen.h = 0;
+
+	env->isinter = 0;
+	env->isrgb24 = 0;
+	env->reverse = 0;
+
+	return env;
+}
+
+void PutDispEnv(const DISPENV *env) {
+	uint32_t h_range, v_range, mode, fb_pos;
+
+	mode  = _gpu_video_mode << 3;
+	mode |= (env->isrgb24 & 1) << 4;
+	mode |= (env->isinter & 1) << 5;
+	mode |= (env->reverse & 1) << 7;
+
+	if (env->disp.h >= 256)
+		mode |= 1 << 2;
+
+	// Calculate the horizontal display range values. The original code was
+	// this bad; in actual fact it was even worse due to being written in
+	// assembly and using slow multiplication even when not necessary.
+	int offset, span, default_span = 2560;
+
+	if (env->disp.w > 560) {
+		// 640 pixels
+		mode  |= 3;
+		offset = 620;
+		span   = env->screen.w * 4;
+	} else if (env->disp.w > 400) {
+		// 512 pixels
+		mode  |= 2;
+		offset = 615;
+		span   = env->screen.w * 4 + env->screen.w;
+	} else if (env->disp.w > 352) {
+		// 384 pixels (this mode is weird)
+		mode  |= 1 << 6;
+		offset = 539;
+		span   = env->screen.w * 8 - env->screen.w;
+		default_span = 2688;
+	} else if (env->disp.w > 280) {
+		// 320 pixels
+		mode  |= 1;
+		offset = 600;
+		span   = env->screen.w * 8;
+	} else {
+		// 256 pixels
+		offset = 590;
+		span   = env->screen.w * 8 + env->screen.w * 2;
+	}
+
+	offset += env->screen.x * 4;
+	if (!span)
+		span = default_span;
+
+	h_range  = offset & 0xfff;
+	h_range |= ((offset + span) & 0xfff) << 12;
+
+	// Calculate the vertical display range values.
+	offset = 16 + env->screen.y;
+	span   = env->screen.h ? env->screen.h : 240;
+
+	v_range  = offset & 0x3ff;
+	v_range |= ((offset + span) & 0x3ff) << 10;
+
+	fb_pos  =  env->disp.x & 0x3ff;
+	fb_pos |= (env->disp.y & 0x1ff) << 10;
+
+	GPU_GP1 = 0x06000000 | h_range; // Set horizontal display range
+	GPU_GP1 = 0x07000000 | v_range; // Set vertical display range
+	GPU_GP1 = 0x08000000 | mode;    // Set video mode
+	GPU_GP1 = 0x05000000 | fb_pos;  // Set VRAM location to display
+}
+
+/* Deprecated "raw" display API */
+
+void PutDispEnvRaw(const DISPENV_RAW *env) {
+	uint32_t h_range, v_range, fb_pos;
+
+	h_range  =   608 + env->vid_xpos;
+	h_range |= (3168 + env->vid_xpos) << 12;
+
+	// FIXME: these hardcoded values are for NTSC displays.
+	v_range  =  (136 - 120 + env->vid_ypos) & 0x3ff;
+	v_range |= ((136 + 120 + env->vid_ypos) & 0x3ff) << 12;
+
+	fb_pos  =  env->fb_x & 0x3ff;
+	fb_pos |= (env->fb_y & 0x1ff) << 10;
+
+	GPU_GP1 = 0x06000000 | h_range;       // Set horizontal display range
+	GPU_GP1 = 0x07000000 | v_range;       // Set vertical display range
+	GPU_GP1 = 0x08000000 | env->vid_mode; // Set video mode
+	GPU_GP1 = 0x05000000 | fb_pos;        // Set VRAM location to display
+}