configurable blend mode

3 files changed, 17 insertions, 3 deletions

diff --git a/demo.c b/demo.c
index 314f39e..48e53d8 100644
--- a/demo.c
+++ b/demo.c
@@ -1,11 +1,13 @@
 #include "lzr.h"
+#include <SDL2/SDL_blendmode.h>
 #include <SDL2/SDL_scancode.h>
 #include <dx/log.h>
 #include <stdbool.h>
 
 int main(void)
 {
-	LZR_Config cfg = {400, 224, 60, 16, "LZR demo", false};
+	LZR_Config cfg = {
+	    400, 224, 60, 16, "LZR demo", false, SDL_BLENDMODE_MUL};
 	if (LZR_Init(cfg))
 		return 1;
 	LZR_ImageLoad("coucou.bmp");
diff --git a/lzr.c b/lzr.c
index 6fcfd16..701ce66 100644
--- a/lzr.c
+++ b/lzr.c
@@ -4,6 +4,7 @@
 #include <SDL2/SDL2_gfxPrimitives.h>
 #include <SDL2/SDL_image.h>
 #include <SDL2/SDL_mixer.h>
+#include <SDL2/SDL_render.h>
 #include <dx/log.h>
 #include <dx/mem.h>
 #include <dx/str.h>
@@ -37,6 +38,7 @@ static SDL_Point *points = NULL;
 static uint64_t tick = 0;
 static Mix_Chunk *sounds[LZR_MAX_SOUNDS] = {0};
 static Mix_Music *music = NULL;
+static SDL_BlendMode blend_mode = SDL_BLENDMODE_NONE;
 
 static int _scode_to_button(unsigned int scode)
 {
@@ -287,6 +289,11 @@ int LZR_ImageLoad(const char *path)
 		return -1;
 	}
 	images[i].tex = tex;
+	blend_mode = config.blend_mode;
+	if (SDL_SetTextureBlendMode(images[i].tex, blend_mode) < 0) {
+		dx_log_error("%s", SDL_GetError());
+		return -1;
+	}
 	if (SDL_QueryTexture(tex, NULL, NULL, &images[i].width,
 	                     &images[i].height)) {
 		dx_log_error("%s", SDL_GetError());
@@ -399,6 +406,10 @@ int LZR_DrawBegin(void)
 		dx_log_error("%s", SDL_GetError());
 		return -1;
 	}
+	SDL_SetRenderDrawBlendMode(renderer, SDL_BLENDMODE_NONE);
+	SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+	SDL_RenderClear(renderer);
+	SDL_SetRenderDrawBlendMode(renderer, blend_mode);
 	return 0;
 }
 
@@ -408,6 +419,7 @@ int LZR_DrawEnd(void)
 		dx_log_error("%s", SDL_GetError());
 		return -1;
 	}
+	SDL_SetRenderDrawBlendMode(renderer, SDL_BLENDMODE_NONE);
 	LZR_DrawSetColor(0.0f, 0.0f, 0.0f);
 	if (LZR_DrawClear()) {
 		dx_log_error("LZY_DrawClear failed");
@@ -429,8 +441,7 @@ int LZR_DrawEnd(void)
 	const int off_y = (win_h - config.display_height * scale) / 2;
 	const SDL_Rect dest = {off_x, off_y, config.display_width * scale,
 	                       config.display_height * scale};
-	if (SDL_RenderCopyEx(renderer, target, NULL, &dest, 0.0, NULL, 0) <
-	    0) {
+	if (SDL_RenderCopyEx(renderer, target, NULL, &dest, 0.0, NULL, 0) < 0) {
 		dx_log_error("%s", SDL_GetError());
 		return -1;
 	}
diff --git a/lzr.h b/lzr.h
index e09a2a5..c03e677 100644
--- a/lzr.h
+++ b/lzr.h
@@ -15,6 +15,7 @@ typedef struct LZR_Config {
 	unsigned int tile_size;
 	const char *title;
 	bool disable_bind_menu;
+	unsigned int blend_mode;
 } LZR_Config;
 
 typedef enum LZR_EventType {