render/gles2: remove current_buffer checks

All backends now use wlr_swapchain. This means the renderer is
guaranteed to have a current_buffer bound.

Remove the legacy code used for EGLSurface.

render/gles2/renderer.c

@@ -34,6 +34,7 @@ static struct wlr_gles2_renderer *gles2_get_renderer_in_context(
 		struct wlr_renderer *wlr_renderer) {
 	struct wlr_gles2_renderer *renderer = gles2_get_renderer(wlr_renderer);
 	assert(wlr_egl_is_current(renderer->egl));
+	assert(renderer->current_buffer != NULL);
 	return renderer;
 }
 
@@ -222,15 +223,7 @@ static void gles2_scissor(struct wlr_renderer *wlr_renderer,
 
 	push_gles2_debug(renderer);
 	if (box != NULL) {
-		struct wlr_box gl_box;
-		if (renderer->current_buffer != NULL) {
-			memcpy(&gl_box, box, sizeof(gl_box));
-		} else {
-			wlr_box_transform(&gl_box, box, WL_OUTPUT_TRANSFORM_FLIPPED_180,
-				renderer->viewport_width, renderer->viewport_height);
-		}
-
-		glScissor(gl_box.x, gl_box.y, gl_box.width, gl_box.height);
+		glScissor(box->x, box->y, box->width, box->height);
 		glEnable(GL_SCISSOR_TEST);
 	} else {
 		glDisable(GL_SCISSOR_TEST);
@@ -277,11 +270,8 @@ static bool gles2_render_subtexture_with_matrix(
 	}
 
 	float gl_matrix[9];
-	if (renderer->current_buffer != NULL) {
 	wlr_matrix_multiply(gl_matrix, flip_180, matrix);
-	} else {
-		memcpy(gl_matrix, matrix, sizeof(gl_matrix));
-	}
+
 	// OpenGL ES 2 requires the glUniformMatrix3fv transpose parameter to be set
 	// to GL_FALSE
 	wlr_matrix_transpose(gl_matrix, gl_matrix);
@@ -334,11 +324,8 @@ static void gles2_render_quad_with_matrix(struct wlr_renderer *wlr_renderer,
 		gles2_get_renderer_in_context(wlr_renderer);
 
 	float gl_matrix[9];
-	if (renderer->current_buffer != NULL) {
 	wlr_matrix_multiply(gl_matrix, flip_180, matrix);
-	} else {
-		memcpy(gl_matrix, matrix, sizeof(gl_matrix));
-	}
+
 	// OpenGL ES 2 requires the glUniformMatrix3fv transpose parameter to be set
 	// to GL_FALSE
 	wlr_matrix_transpose(gl_matrix, gl_matrix);
@@ -367,11 +354,8 @@ static void gles2_render_ellipse_with_matrix(struct wlr_renderer *wlr_renderer,
 		gles2_get_renderer_in_context(wlr_renderer);
 
 	float gl_matrix[9];
-	if (renderer->current_buffer != NULL) {
 	wlr_matrix_multiply(gl_matrix, flip_180, matrix);
-	} else {
-		memcpy(gl_matrix, matrix, sizeof(gl_matrix));
-	}
+
 	// OpenGL ES 2 requires the glUniformMatrix3fv transpose parameter to be set
 	// to GL_FALSE
 	wlr_matrix_transpose(gl_matrix, gl_matrix);
@@ -454,19 +438,19 @@ static enum wl_shm_format gles2_preferred_read_format(
 	struct wlr_gles2_renderer *renderer =
 		gles2_get_renderer_in_context(wlr_renderer);
 
-	GLint gl_format = -1, gl_type = -1;
 	push_gles2_debug(renderer);
+
+	GLint gl_format = -1, gl_type = -1;
 	glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_FORMAT, &gl_format);
 	glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_TYPE, &gl_type);
-	pop_gles2_debug(renderer);
 
 	EGLint alpha_size = -1;
-	if (renderer->current_buffer != NULL) {
 	glBindRenderbuffer(GL_RENDERBUFFER, renderer->current_buffer->rbo);
 	glGetRenderbufferParameteriv(GL_RENDERBUFFER,
 		GL_RENDERBUFFER_ALPHA_SIZE, &alpha_size);
 	glBindRenderbuffer(GL_RENDERBUFFER, 0);
-	}
+
+	pop_gles2_debug(renderer);
 
 	const struct wlr_gles2_pixel_format *fmt =
 		get_gles2_format_from_gl(gl_format, gl_type, alpha_size > 0);
@@ -508,41 +492,26 @@ static bool gles2_read_pixels(struct wlr_renderer *wlr_renderer,
 
 	unsigned char *p = (unsigned char *)data + dst_y * stride;
 	uint32_t pack_stride = width * fmt->bpp / 8;
-	if (pack_stride == stride && dst_x == 0 && flags != NULL) {
+	if (pack_stride == stride && dst_x == 0) {
 		// Under these particular conditions, we can read the pixels with only
 		// one glReadPixels call
 
-		uint32_t y = src_y;
-		if (renderer->current_buffer == NULL) {
-			y = renderer->viewport_height - height - src_y;
-		}
-
-		glReadPixels(src_x, y, width, height, fmt->gl_format, fmt->gl_type, p);
-
-		if (renderer->current_buffer != NULL) {
-			*flags = 0;
-		} else {
-			*flags = WLR_RENDERER_READ_PIXELS_Y_INVERT;
-		}
+		glReadPixels(src_x, src_y, width, height, fmt->gl_format, fmt->gl_type, p);
 	} else {
 		// Unfortunately GLES2 doesn't support GL_PACK_*, so we have to read
 		// the lines out row by row
 		for (size_t i = 0; i < height; ++i) {
 			uint32_t y = src_y + i;
-			if (renderer->current_buffer == NULL) {
-				y = renderer->viewport_height - src_y - i - 1;
-			}
-
 			glReadPixels(src_x, y, width, 1, fmt->gl_format,
 				fmt->gl_type, p + i * stride + dst_x * fmt->bpp / 8);
 		}
+	}
+
+	pop_gles2_debug(renderer);
 
 	if (flags != NULL) {
 		*flags = 0;
 	}
-	}
-
-	pop_gles2_debug(renderer);
 
 	return glGetError() == GL_NO_ERROR;
 }
@@ -565,7 +534,7 @@ static bool gles2_blit_dmabuf(struct wlr_renderer *wlr_renderer,
 		goto restore_context_out;
 	}
 
-	// TODO: get inverted_y right when current_buffer != NULL
+	// TODO: get inverted_y right
 	// This is to take into account y-inversion on both buffers rather than
 	// just the source buffer.
 	bool src_inverted_y =
@@ -574,11 +543,6 @@ static bool gles2_blit_dmabuf(struct wlr_renderer *wlr_renderer,
 		!!(dst_attr->flags & WLR_DMABUF_ATTRIBUTES_FLAGS_Y_INVERT);
 	struct wlr_gles2_texture *gles2_src_tex = gles2_get_texture(src_tex);
 	gles2_src_tex->inverted_y = src_inverted_y ^ dst_inverted_y;
-	if (renderer->current_buffer == NULL) {
-		// The result is negated because wlr_matrix_projection y-inverts the
-		// texture.
-		gles2_src_tex->inverted_y = !gles2_src_tex->inverted_y;
-	}
 
 	if (!wlr_egl_make_current(renderer->egl)) {
 		goto texture_destroy_out;