From 3e4d0b255a3363dc19e8db99845121b2b401e475 Mon Sep 17 00:00:00 2001
From: kdx <kikoodx@paranoici.org>
Date: Mon, 27 Mar 2023 08:59:27 +0200
Subject: mouse position and screen transform

---
 headers/TZR_events.h           |  2 ++
 headers/TZR_globals.h          |  3 +++
 headers/TZR_render.h           |  2 ++
 sources/TZR_DrawEnd.c          | 18 +++++++++---------
 sources/TZR_GetMousePosition.c | 12 ++++++++++++
 sources/TZR_ScreenTransform.c  | 16 ++++++++++++++++
 sources/globals.c              |  3 +++
 7 files changed, 47 insertions(+), 9 deletions(-)
 create mode 100644 sources/TZR_GetMousePosition.c
 create mode 100644 sources/TZR_ScreenTransform.c

diff --git a/headers/TZR_events.h b/headers/TZR_events.h
index 4b2b0c6..61262c8 100644
--- a/headers/TZR_events.h
+++ b/headers/TZR_events.h
@@ -6,3 +6,5 @@ int TZR_PollEvent(TZR_Event *e);
 
 /* Drain queued events with TZR_PollEvent and call TZR_ResourcesWatch. */
 void TZR_CycleEvents(void);
+
+void TZR_GetMousePosition(int *x, int *y);
diff --git a/headers/TZR_globals.h b/headers/TZR_globals.h
index 4f8c00c..548110b 100644
--- a/headers/TZR_globals.h
+++ b/headers/TZR_globals.h
@@ -20,3 +20,6 @@ extern int ___tzr_mouse_y;
 extern const char *___tzr_command[___TZR_RES_COUNT];
 extern TZR_KeyState ___tzr_keystates[SDL_NUM_SCANCODES];
 extern TZR_KeyState ___tzr_mousestates[256];
+extern float ___tzr_scale;
+extern int ___tzr_off_x;
+extern int ___tzr_off_y;
diff --git a/headers/TZR_render.h b/headers/TZR_render.h
index 2ba0b3c..592440c 100644
--- a/headers/TZR_render.h
+++ b/headers/TZR_render.h
@@ -55,3 +55,5 @@ int TZR_DrawRectangle(bool fill, int x, int y, int w, int h);
 [[nodiscard]]
 #endif
 int _TZR_DrawImage(const TZR_DrawImageArgs *args);
+
+void TZR_ScreenTransform(int *x, int *y);
diff --git a/sources/TZR_DrawEnd.c b/sources/TZR_DrawEnd.c
index ba379be..38c8e1b 100644
--- a/sources/TZR_DrawEnd.c
+++ b/sources/TZR_DrawEnd.c
@@ -22,16 +22,16 @@ TZR_DrawEnd(void)
 
 	const float ratio_w = win_w / (float)___tzr_config.width;
 	const float ratio_h = win_h / (float)___tzr_config.height;
-	float scale = (ratio_w < ratio_h) ? ratio_w : ratio_h;
-	if (scale > 1.0f && ___tzr_config.pixel_perfect)
-		scale = (int)scale;
-	const int off_x = (win_w - ___tzr_config.width * scale) / 2;
-	const int off_y = (win_h - ___tzr_config.height * scale) / 2;
+	___tzr_scale = (ratio_w < ratio_h) ? ratio_w : ratio_h;
+	if (___tzr_scale > 1.0f && ___tzr_config.pixel_perfect)
+		___tzr_scale = (int)___tzr_scale;
+	___tzr_off_x = (win_w - ___tzr_config.width * ___tzr_scale) / 2;
+	___tzr_off_y = (win_h - ___tzr_config.height * ___tzr_scale) / 2;
 	const SDL_Rect dest = {
-		off_x,
-		off_y,
-		___tzr_config.width * scale,
-		___tzr_config.height * scale
+		___tzr_off_x,
+		___tzr_off_y,
+		___tzr_config.width * ___tzr_scale,
+		___tzr_config.height * ___tzr_scale
 	};
 
 	if (SDL_RenderCopy(___tzr_renderer, ___tzr_target, NULL, &dest) < 0)
diff --git a/sources/TZR_GetMousePosition.c b/sources/TZR_GetMousePosition.c
new file mode 100644
index 0000000..f09bd22
--- /dev/null
+++ b/sources/TZR_GetMousePosition.c
@@ -0,0 +1,12 @@
+#include "TZR_globals.h"
+#include "TZR_render.h"
+
+void
+TZR_GetMousePosition(int *x, int *y)
+{
+	if (x != NULL)
+		*x = ___tzr_mouse_x;
+	if (y != NULL)
+		*y = ___tzr_mouse_y;
+	TZR_ScreenTransform(x, y);
+}
diff --git a/sources/TZR_ScreenTransform.c b/sources/TZR_ScreenTransform.c
new file mode 100644
index 0000000..d936781
--- /dev/null
+++ b/sources/TZR_ScreenTransform.c
@@ -0,0 +1,16 @@
+#include "TZR_globals.h"
+
+void
+TZR_ScreenTransform(int *x, int *y)
+{
+	if (___tzr_scale == 0.0)
+		return;
+	if (x != NULL) {
+		*x -= ___tzr_off_x;
+		*x /= ___tzr_scale;
+	}
+	if (y != NULL) {
+		*y -= ___tzr_off_y;
+		*y /= ___tzr_scale;
+	}
+}
diff --git a/sources/globals.c b/sources/globals.c
index badcc1e..7c4f26b 100644
--- a/sources/globals.c
+++ b/sources/globals.c
@@ -20,3 +20,6 @@ int ___tzr_mouse_y = 0;
 const char *___tzr_command[___TZR_RES_COUNT] = {};
 TZR_KeyState ___tzr_keystates[SDL_NUM_SCANCODES] = {};
 TZR_KeyState ___tzr_mousestates[256] = {}; //doc says than mouse button is u8
+float ___tzr_scale = 1.0;
+int ___tzr_off_x = 1.0;
+int ___tzr_off_y = 1.0;
-- 
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