render: Introduce wlr_render_texture_options.blend_mode

include/wlr/render/wlr_renderer.h

@@ -221,6 +221,8 @@ struct wlr_render_texture_options {
 	enum wl_output_transform transform;
 	/* Filtering */
 	enum wlr_scale_filter_mode filter_mode;
+	/* Blend mode */
+	enum wlr_render_blend_mode blend_mode;
 };
 
 /**

render/gles2/pass.c

@@ -121,6 +121,17 @@ static void set_tex_matrix(GLint loc, enum wl_output_transform trans,
 	glUniformMatrix3fv(loc, 1, GL_FALSE, tex_matrix);
 }
 
+static void setup_blending(enum wlr_render_blend_mode mode) {
+	switch (mode) {
+	case WLR_RENDER_BLEND_MODE_PREMULTIPLIED:
+		glEnable(GL_BLEND);
+		break;
+	case WLR_RENDER_BLEND_MODE_NONE:
+		glDisable(GL_BLEND);
+		break;
+	}
+}
+
 static void render_pass_add_texture(struct wlr_render_pass *wlr_pass,
 		const struct wlr_render_texture_options *options) {
 	struct wlr_gles2_render_pass *pass = get_render_pass(wlr_pass);
@@ -159,12 +170,8 @@ static void render_pass_add_texture(struct wlr_render_pass *wlr_pass,
 	src_fbox.height /= options->texture->height;
 
 	push_gles2_debug(renderer);
-
-	if (!texture->has_alpha && alpha == 1.0) {
-		glDisable(GL_BLEND);
-	} else {
-		glEnable(GL_BLEND);
-	}
+	setup_blending(!texture->has_alpha && alpha == 1.0 ?
+		WLR_RENDER_BLEND_MODE_NONE : options->blend_mode);
 
 	glUseProgram(shader->program);
 
@@ -202,19 +209,7 @@ static void render_pass_add_rect(struct wlr_render_pass *wlr_pass,
 	const struct wlr_box *box = &options->box;
 
 	push_gles2_debug(renderer);
-
-	switch (options->blend_mode) {
-	case WLR_RENDER_BLEND_MODE_PREMULTIPLIED:
-		if (color->a == 1.0) {
-			glDisable(GL_BLEND);
-		} else {
-			glEnable(GL_BLEND);
-		}
-		break;
-	case WLR_RENDER_BLEND_MODE_NONE:
-		glDisable(GL_BLEND);
-		break;
-	}
+	setup_blending(color->a == 1.0 ? WLR_RENDER_BLEND_MODE_NONE : options->blend_mode);
 
 	glUseProgram(renderer->shaders.quad.program);
 

render/pass.c

@@ -113,10 +113,16 @@ static void legacy_add_texture(struct wlr_render_pass *wlr_pass,
 	pixman_region32_t clip;
 	get_clip_region(pass, options->clip, &clip);
 
+	float black[4] = {0};
 	int rects_len = 0;
 	const pixman_box32_t *rects = pixman_region32_rectangles(&clip, &rects_len);
 	for (int i = 0; i < rects_len; i++) {
 		scissor(pass->renderer, &rects[i]);
+
+		if (options->blend_mode == WLR_RENDER_BLEND_MODE_NONE) {
+			wlr_renderer_clear(pass->renderer, black);
+		}
+
 		wlr_render_subtexture_with_matrix(pass->renderer, texture, &src_box, matrix, alpha);
 	}
 

render/pixman/pass.c

@@ -26,6 +26,16 @@ static bool render_pass_submit(struct wlr_render_pass *wlr_pass) {
 	return true;
 }
 
+static pixman_op_t get_pixman_blending(enum wlr_render_blend_mode mode) {
+	switch (mode) {
+	case WLR_RENDER_BLEND_MODE_PREMULTIPLIED:
+		return PIXMAN_OP_OVER;
+	case WLR_RENDER_BLEND_MODE_NONE:
+		return PIXMAN_OP_SRC;
+	}
+	abort();
+}
+
 static void render_pass_add_texture(struct wlr_render_pass *wlr_pass,
 		const struct wlr_render_texture_options *options) {
 	struct wlr_pixman_render_pass *pass = get_render_pass(wlr_pass);
@@ -129,8 +139,10 @@ static void render_pass_add_texture(struct wlr_render_pass *wlr_pass,
 		break;
 	}
 
+	pixman_op_t op = get_pixman_blending(options->blend_mode);
+
 	pixman_image_set_clip_region32(buffer->image, (pixman_region32_t *)options->clip);
-	pixman_image_composite32(PIXMAN_OP_OVER, texture->image, mask,
+	pixman_image_composite32(op, texture->image, mask,
 		buffer->image, src_box.x, src_box.y, 0, 0, dest_x, dest_y,
 		width, height);
 	pixman_image_set_clip_region32(buffer->image, NULL);
@@ -152,16 +164,8 @@ static void render_pass_add_rect(struct wlr_render_pass *wlr_pass,
 	struct wlr_pixman_buffer *buffer = pass->buffer;
 	struct wlr_box box = options->box;
 
-	pixman_op_t op = 0;
-	switch (options->blend_mode) {
-	case WLR_RENDER_BLEND_MODE_PREMULTIPLIED:
-		op = options->color.a == 1 ? PIXMAN_OP_SRC : PIXMAN_OP_OVER;
-		break;
-	case WLR_RENDER_BLEND_MODE_NONE:
-		op = PIXMAN_OP_SRC;
-		break;
-	}
-	assert(op != 0);
+	pixman_op_t op = get_pixman_blending(options->color.a == 1 ?
+		WLR_RENDER_BLEND_MODE_NONE : options->blend_mode);
 
 	struct pixman_color color = {
 		.red = options->color.r * 0xFFFF,

render/vulkan/pass.c

@@ -550,6 +550,8 @@ static void render_pass_add_texture(struct wlr_render_pass *wlr_pass,
 				.filter_mode = options->filter_mode,
 			},
 			.texture_transform = texture->transform,
+			.blend_mode = !texture->has_alpha && alpha == 1.0 ?
+				WLR_RENDER_BLEND_MODE_NONE : options->blend_mode,
 		});
 	if (!pipe) {
 		pass->failed = true;